Improving Sphenophorus levis Adult Mortality with Solid Insecticide Applications and Increased Insecticide Dose

Improving Sphenophorus levis Adult Mortality with Solid Insecticide Applications and Increased Insecticide Dose | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Improving Sphenophorus levis Adult Mortality with Solid Insecticide Applications and Increased Insecticide Dose Pedro Henrique Urach Ferreira, Marcelo da Costa Ferreira, Eliane Vieira This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4018984/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract The sugarcane weevil ( Sphenophorus levis Vaurie, 1978) is currently considered the most important sugarcane pest in Brazil causing significant yield losses. Application methods of insecticides for S. levis control have not been effective mostly due to the insect’s habitat behavior bellow soil surface suppressing the correct placement of the insecticide active ingredient on target. Two experiments were conducted using a novel bioassay methodology that simulates sugarcane field conditions to effectively evaluate S. levis adult mortality and insecticide soil residue under different treatments. One study aimed to assess the efficacy of two liquid and solid applied insecticides while the second aimed to examinate the effect of increasing lambda-cyhalothrin + thiamethoxam dose on S. levis adult control. The novel bioassays simulated liquid and solid insecticide applications on sugarcane and exposed S. levis adults to residual rhizome and soil after insecticide application. In the first experiment, low S. levis adult control was detected (< 53% mortality) across all treatments where both solid and liquid applications of lambda-cyhalothrin + thiamethoxam provided greater efficacy levels than imidacloprid and control treatments, respectively. Solid applications promoted greater insecticide concentrations in soil during longer periods in comparison with liquid insecticide applications, providing maximum insect control levels at 7 days after application. In the second experiment, solid applications at higher insecticide dose significantly improved S. levis adult control (76.7% mortality) in comparison with results of recommended label rate for adult control (58.8% mortality). Billbug sugarcane weevil granular residue mortality Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction The sugarcane weevil [ Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae)] is considered one of the most important pests in sugarcane ( Saccharum officinarum L.) in Brazil. It was first reported in 1977 (Degaspari et al. 1987 ) but had its importance significantly increased in the last twenty years following the shift of cane harvesting system, from manual harvesting of burnt cane to mechanical harvesting of green cane. Burning sugarcane as a harvesting tool had a direct impact on pest control. After the new mechanical harvesting system without burning was implemented, an increase of pest pressure in sugarcane has been noticed, especially for sugarcane borer [ Diatraea saccharalis Fabricius (Lepidoptera: Crambidae)], root spittlebug [ Mahanarva fimbriolatta Stål (Hemiptera; Cercopidae] and S. levis (Dinardo-Miranda and Fracasso 2013 ). Since then, S. levis has caused great and increasing damage for sugarcane growers with losses up to 30 t ha − 1 (Precetti and Arrigoni, 1990 ). It has been reported, for instance, that every 1% of damage caused by S. levis resulted in 1% yield loss (Casteliani et al. 2020 ). Sphenophorus levis is a soil-inhabiting pest that damages sugarcane plants by larvae feeding the rhizome. Its larvae stage is, on average, 50 days long, followed by the pupae period with mean duration of 12 days while S. levis adults can live up to 250 days (Degaspari et al. 1987 ; Casteliani et al. 2020 ). Females deposit their eggs inside the sugarcane base and rhizome where it hatches and the larvae starts to feed causing the main damage. Larvae’s damage in the rhizome is characterized by a white/yellow frass formed inside tunnels. Plant symptoms include leaf yellowing, starting from outer leaves, leaf necrosis, followed by plant death forming yellow/brown patches distributed across the field. Nearly 90% of formed tunnels are opened bellow soil surface and most of rhizome’s openings are filled with soil or with the white/yellow frass (Casteliani et al. 2020 ). In addition to pest’s immature stages hiding inside buried rhizomes, S. levis adults are also mostly hidden underground as it has been previously observed (Ferreira 2022). Due to the pest’s biology and behavior location underneath the soil, it has been extremely difficult to obtain effective control levels of S. levis . Specific S. levis management alternatives have been developed in sugarcane farming systems, including the desiccation with herbicides and destruction of volunteer cane, insect baiting and biological and chemical insecticide applications during planting and ratoon treatment. However, despite the development of different methods, low efficacy of control has been achieved, especially in insecticide applications (Dinardo-Miranda et al. 2006 ; Tavares 2006 ; Alencar 2016 ). Among the insecticide application methods currently being used for S. levis control, the most common in ratoon treatments is conducted with ratoon drill applicators. This equipment physically opens the rhizome with a drilling disc at each sugarcane row and applies insecticides through a full jet spray in the rhizome aiming to deposit the active ingredient as close as possible to the target. Unfortunately, this method has not been fully effective, possibly due to inaccurate applications and low insecticide residual. In one study evaluating different insecticides for S. levis control, the mean insecticide efficacy was of only 60% (Dinardo-Miranda et al. 2006 ). In another study comparing several insecticides, no treatment was effective to reduce S. levis infestation or to improve sugarcane yield in comparison with the untreated control (Alencar, 2006). All insecticides currently being used for S. levis control are liquid applied through hydraulic nozzles while no solid applications of granular insecticides are used. Meanwhile, several authors have reported pest control benefits when adopting the application of solid insecticides (Buhler and Gibb 1993 ; Roy et al. 2014 ; Ward 2016 ; Allsopp 2020 , Pandey and Kumar 2020 ). Granular applications of imidacloprid with controlled-release technology, for example, have provided up to 4 years of satisfactory canegrub control (Ward 2016 ). Granular insecticides may improve S. levis control through the gradual release of the active ingredient concentrated on a granule to the soil profile and for plant uptake. In addition, insecticide concentrations being gradually released underneath the soil could enhance insect control especially due to the gregarious characteristic of this and other Curculionidae species. Moreover, considering the low efficacy of current insecticides, dose-response studies comparing different product concentrations should be conducted to evaluate if recommended rates are in fact effective or not for S. levis control. Studying the lethal concentration of different insecticides for hunting billbug ( Sphenophorus venatus vestitus Chittenden) control, for example, authors reported it was necessary 6.4 times more insecticide concentration to provide 95% billbug mortality (LC 95 ) compared to the concentration required to control 50% of insects (LC 50 ) (Doskocil et al. 2012 ). Due to ineffective S. levis control with current insecticide application methods and recommended product rates, the present study aimed to evaluate the efficacy of two insecticides products (lambda-cyhalothrin + thiamethoxam and imidacloprid) applied through solid and liquid application and to compare two insecticide rates (recommended and double dose) on S. levis adult control through a novel bioassay methodology. 2. Materials and Methods 2.1. Experiment 1 – Liquid and Solid Application of Insecticides An insecticide efficacy study in ratoon sugarcane for S. levis adult control was conducted in 2021 in Jaboticabal, SP, Brazil. The experiment was conducted in a factorial arrangement of treatments (three efficacy evaluation dates by five application treatments) in a completely randomized design with four replications. The experiment was performed in duplicate with insecticide treatment applications on May 27th and June 8th, respectively. 2.1.1. Sugarcane plants Seedlings of sugarcane variety CTC 4 (Centro de Tecnologia Canavieira S.A., Piracicaba, SP, Brazil) were planted on November 19th, 2020, in 50 L pots of 0.44 m 2 diameter containing a mixture of soil, sand and manure in a proportion mix of 3:1:1, respectively (Fig. 1 a). Pot mixture was sent for soil analysis at the Soil Fertility Laboratory at UNESP following known methodology (Raij et al. 2001 ) for organic matter content (14 g dm − 3 ) cation exchange capacity (73 mmol c dm − 3 ), base saturation (81%) and soil pH (6.0). Sugarcane pots were continuously watered through drip irrigation (Fig. 1 b) with 10 mm of water per day. On April 29th, 162 days after planting, sugarcane plants of the first experiment duplicate were manually harvested (Fig. 1 c and 1 d). Harvesting was conducted to induce sugarcane ratoon shoots and tillering. On May 13th, the second experiment duplicate was harvested. All plant residue (dry leaves) from each pot was placed on the soil surface of the corresponding harvested pot. The average amount of residue was of 220 g per sugarcane pot (5,000.0 kg ha − 1 ). 2.1.2. Treatment Application Insecticide treatment application was conducted on ratoon sugarcane plants 28 days after harvesting. The first and second experiment duplicates had insecticide treatments applied on May 27th and June 8th, respectively. As the experiment aimed to simulate ratoon drill application of insecticides in field, ratoon cane plants in each pot were manually cut using a small size axe. A vertical and uniform drill depth of 10 cm was ensured using a 30 cm rule (Fig. 1 e). As in field ratoon applications, in which insecticides are applied right after a drilling disc mechanically opens sugarcane tillers and rhizomes, experiment treatments were applied in the same manner after manual drilling. Two insecticides were used with two application methods (solid and liquid application) and one untreated check as in Table 1 . Insecticide dose was calculated based on the average surface area of sugarcane cylindrical pots, 0.44 m 2 , and the recommended dose of each insecticide in grams per hectare (g ha − 1 ) following the Eq. 1 (Eq. 1) where CID is the Calculated Insecticide Dose given in g per treated pot and RCPD is the Recommended Commercial Product Dose given in g ha − 1 : Table 1 Insecticide application treatments including insecticides, trade names, dose, and active ingredient application rate Application treatments Trade name Dose a.i. Rate L or kg ha − 1 g ha − 1 T1 - untreated --------- --------- --------- T2 - liquid - lambda-cyhalothrin + thiamethoxam 1 Engeo Pleno™ S 2.0 L ha − 1 212 + 282 T3 - solid - lambda-cyhalothrin + thiamethoxam 2 Kaiso Sorbie BR GR + 1 Actara® 250 WG 0.883 + 1.128 kg ha − 1 212 + 282 T4 - liquid - imidacloprid 3 Warrant® 700 WG 1.5 kg ha − 1 1200 T5 - solid - imidacloprid Warrant® 700 WG 1.5 kg ha − 1 1200 1 Syngenta, Basel, Switzerland; 2 Nufarm Limited, Laverton North, VIC, Australia; 3 FMC Química do Brasil Ltda, SP, Brazil. $$CID=\frac{0.44 x RCPD}{10000}\text{ }\text{ }\text{ }\text{ }\text{(1)}$$ Liquid treatments were applied adopting an application water volume of 200 L ha − 1 and using a 10 mL syringe size that was constantly pressed towards the entire rhizome cut and pot diameter (Fig. 1 f). Solid treatments were manually applied inside the whole plant fissure ensuring uniform granular application (Fig. 1 f). Air temperature and relative humidity were measured during insecticide treatment applications with a digital thermo hygrometer Jprolab (JProlab, São José dos Pinhais, PR, Brazil). Pot subsurface soil temperature was measured with a digital thermometer TE-400 (Instrutherm, São Paulo, SP, Brazil) and soil humidity was assessed with a ph-2500 pH/soil humidity meter (Instrutherm, São Paulo, SP, Brazil). Daily meteorological data including the entire study period was received from the Processing, Automatization and Instrumentalization Laboratory (LIAP) at the Exact Sciences and Engineering Department at FCAV/UNESP, Jaboticabal, SP, Brazil. The data was obtained from an automatic weather station (Davis Instruments, Hayward, CA, USA) closely installed to the study area in the LIAP premises. Average meteorological and soil conditions during application are available in Table 2 and additional data of mean rainfall and temperature during the study period is available in the Online Resource 1. Table 2 Harvest date, meteorological and soil conditions of each duplicate in experiment 1 Duplicate 1 Duplicate 2 Harvest date 29/04/2021 13/05/2021 Treatment application date 27/05/2021 08/06/2021 Temperature (°C) 28.9 25.9 Relative humidity (%) 43.0 67.5 Soil temperature (°C) 24.2 25.0 Soil humidity (%) 53.6 54.0 First rain after application / rain amount 14 DAA / 24.8 mm 2 DAA / 24.8 mm 2.1.3. Plant and Soil Removal Treated sugarcane rhizome, tiller and soil were removed for insect exposure and residue evaluation in three different dates including 1 day after application (DAA), 7 and 14 DAA. In each insect exposure period, sugarcane rhizomes were manually extracted from all pots with a grubbing hoe (Fig. 2 a). Extracted plants were manually chopped in small pieces (6 cm) using a machete and were placed in individual plastic bags. A uniform amount of treated soil (265 g) was collected from the 5 cm surface of each pot and was placed in identified individual plastic bags. To avoid any source of contamination during plant and soil removal, both grubbing hoe and machete were washed with water and soap between each pot extraction procedure. 2.1.4. Insects Sphenophorus levis adults used in the mortality evaluations of the experiment were collected between March and May of 2021 in sugarcane fields with previous infestation history and no insecticide application in the year. Sugarcane stalks cut in half (30 cm) were used as S. levis baits. Following an adapted methodology (Pérez 2008 ), cane stalks were immersed in 50 L water containers with 10% of melted sugar solution for 24 h. The following day, cane baits were distributed in sugarcane fields with the stalk cut in half section facing the soil and were covered with sugarcane residue. Five days after bait distribution, S. levis adults found in baits were collected and placed in containers with cane stalks in it. Collected insects were maintained in rectangular plastic containers (15 cm x 11 cm x 6 cm) sealed with small punctured lids for air exchange. In each container 30 adults of S. levis were placed with 3 cane stalks cut in half (14 cm). Containers were cleaned with soap and 70% ethyl alcohol and sugarcane stalks were replaced every four days. Insects were maintained under 12 h photoperiod, at room temperature (23.2°C ± 1.5) and relative humidity (65% ± 12) until were used in the insecticide efficacy study. Room temperature and relative humidity were measured with a digital thermo hygrometer Jprolab (JProlab, São José dos Pinhais, PR, Brazil). 2.1.5. Insecticide Soil Residue Analysis Soil samples (265 g) that were collected from the 5 cm surface of each pot were stored in plastic bags (-20°C) in complete darkness and were transported in thermal boxes to the Agrochemicals Ecology Laboratory from the Biological Institute at São Paulo, SP, Brazil. For each experiment duplicate, individual soil samples of each pot and treatment were then air-dried at ambient conditions, homogenized, sieved at 2 mm mesh size and stored in plastic bag (-20ºC) in complete darkness prior to extraction and analysis. The extraction procedure was based on QuEChERS (quick, easy, cheap, rugged and safe) method (Anastassiades et al. 2003 ). A dried soil sample (10 g) was placed in a 50 mL polypropylene centrifugation tube and rehydrated with 2 mL distilled water. Then the samples were mixed manually for 30 seconds. Subsequently, 2 g of sodium acetate and 20 mL of acetonitrile containing 1% acetic acid (ACN 1% HAc; extraction solvent) was added. The tube with this mixture was agitated vigorously for 5 minutes, after which, 2 g of sodium chloride and 8 g of magnesium sulfate were added to the tube and again agitated vigorously for 5 min. The tube was then shaken for 30 minutes in an agitator and it was centrifuged for 5 minutes at 3000 rpm. 6 mL of supernatant was transferred to a 15 mL polyethylene tube with 900 mg of anhydrous MgSO4, and 300 mg of PSA. The tubes were mixed manually for 1 minute and centrifuged at 3000 rpm for 5 minutes. The supernatant was filtered through a 0.22 um filter membrane. Imidacloprid and thiamethoxam were analyzed in a liquid chromatography-tandem mass spectrometry Shimadzu 40DXS HPLC (Shimadzu Corporation, Kyoto, Japan) coupled to a Shimadzu 8050 Triple Quad-LC-MS/MS (Shimadzu Corporation, Kyoto, Japan). Chromatographic separation was performed on a Shim-pack Velox C18 of 2.7 µm × 2.1 mm × 100 mm (Shimadzu Corporation, Kyoto, Japan). Mobile phase A was 5 mmol L − 1 ammonium acetate-water, mobile phase B was 5 mmol L − 1 ammonium acetate-methanol at a constant flow rate of 0.3 mL min − 1 . The optimized gradient program was 3% of B (initial conditions) for 1.5 minutes, after a linear gradient up to 95% of B in 8.75 minutes and finally, the mobile phase came back to the initial conditions (3% B) at 8.76 minutes. The total run time was 10 minutes and the injection volume was 10 µL. The HPLC was coupled to a MS/MS with an ESI source, operating with positive and negative ionization modes. Nitrogen was used as the nebulizer gas and argon as the collision gas. Lambda cyhalothrin was analyzed with Agilent 7890 Gas Chromatograph (Agilent Technologies, Santa Clara, CA, USA) equipped with an electron capture detector (ECD) 320ºC. A HP-5MS (30 m × 0.320 mm × 0.25 µm) (Agilent Technologies, Santa Clara, CA, USA) capillary column was used. The temperature program was as follows: primary temperature, 100°C held for 1 min, then increased with the rate of 10°C/min to 280°C. The injection port temperature was set at 230°C and a volume of 1 µL was injected in a splitless mode. 2.1.6. Insecticide Efficacy for S. levis control Cane rhizomes, tillers and soil that were removed from each treated pot and placed in individual bags were weighed with a GF-1000 precision scale (A&D Company, Limited, Tokyo, Japan). 50 g of treated soil and 85 g of chopped rhizomes, with average length of 6 cm, from each pot were placed in 1 L round containers. Four S. levis adults were then placed in each round container for treatment exposure. One treated sugarcane pot was used to fill two containers with soil, rhizome and insects. The containers were maintained in a laboratory room with 12 h of photoperiod, room temperature (22.0°C ± 1.3) and relative humidity (64% ± 7). After 96 hours of S. levis insect’s initial exposure to treated soil and rhizomes, insects were replaced to new 1 L containers with one half sliced cane stalk inside it, with average weight of 40 g and 10 cm long. These new containers were now filled with eight insects from two containers with soil and rhizome of the same treated pot. Thus, each new container had 8 insects that were in contact with treated soil and rhizome of the same individual sugarcane pot. Insects were kept inside the new containers with cane stalks for 96 h until the first mortality evaluation. The mortality evaluation consisted of counting the number of live, moribund and dead S. levis adults in each container. As S. levis exhibits the behavior of thanatosis, insects were considered dead when no movement was noticed during one minute and when no movement was observed after an involuntary reflex was induced (slight grasp in the abdomen with entomology forceps). Insects were considered live when vigorous and expected movement (insect walking; movement of legs, antenna and head) were observed. The insects assessed as moribund were either lying on their back, even after flipping the insects over, or had an atypical slow and uncoordinated body-part movement. There was a total of three insect control evaluations dates including at 8 days, at 12 days and at 14 days after insect exposure (DAIE) to treated soil and rhizomes. At every mortality evaluation, live and moribund insects were replaced to new containers with half sliced cane stalk. Dead S. levis adults were discarded. 2.2. Experiment 2 – Insecticide Rate Comparison in Solid Application A second insecticide efficacy experiment was conducted. The experiment aimed to evaluate solid application efficacy of one insecticide mixture at two rates. The insecticide mixture consisted of lambda-cyhalothrin (Kaiso Sorbie BR GR, Nufarm Limited, Laverton North, VIC, Australia) with thiamethoxam (Actara® 250 WG, Syngenta, Basel, Switzerland). Treatments included granular lambda-cyhalothrin + thiamethoxam at two rates: 212 + 282 and 424 + 564 g a.i. ha − 1 , respectively. All experiment methodology steps (planting, harvesting, treatment application, plant/soil removal, insecticide residue analysis and laboratory work) were conducted as previously described in Experiment 1. Harvesting was conducted on May 13th and treatment applications on ratoon cane of first and second duplicates were made on August 13th and August 26th, respectively. The only differences between methodologies were that in Experiment 2 only one period of soil/rhizome removal and insect exposure (14 DAA) was adopted, a total of eight round containers with twelve S. levis adults were used for each insecticide rate and four evaluation periods were conducted including 4, 8, 12 and 14 days after insect exposure (DAIE) to treated soil and rhizomes. Average meteorological and soil conditions during application are available in Table 3 and additional data of mean rainfall and temperature during the study period is available in the Online Resource 1. Table 3 Harvest date, meteorological and soil conditions of each duplicate in experiment 2 Duplicate 1 Duplicate 2 Harvest date 13/05/2021 13/05/2021 Treatment application date 13/08/2021 26/08/2021 Temperature (°C) 27.4 29.0 Relative humidity (%) 32.5 35.0 Soil temperature (°C) 28.1 30.7 Soil humidity (%) 56.2 57.0 First rain after application / rain amount 3 DAA / 4.2 mm 0 mm 2.3. Data analysis Descriptive analysis and model fitness were conducted in RStudio Version 1.4.1717 software (RStudioTeam 2021) for the dependent variables of dead and moribund S. levis adults. Before selection of the best model, different model error distributions and link functions were tested and adjusted to correct for overdispersion and assess goodness of fit. To select the best model, model’s performances were compared by half-normal plots with simulation envelopes using the hnp package in R software (Moral et al. 2017 ). Sphenophorus levis mortality and moribund percentage data of each period after application and each evaluation date was treated as dependent variable in a quasibinomial generalized linear model with application treatment as the independent variable in experiment 1 and with insecticide rate as the independent variable in experiment 2. After model selection, results of S. levis mortality and moribund percentage were submitted to an analysis of deviance (type II Wald chi-square tests) for main effects. Significant effects were analyzed using the emmeans package with Sidak’s test at p < 0.05 (Lenth 2019 ) to determine significant differences between treatments. Treatment efficacy was calculated using Schneider-Orelli’s correction formula (Schneider-Orelli 1947 ) in which it considers both mortality of treated and untreated mean values in its equation. 3. Results 3.1. Experiment 1 - Liquid and Solid Application of Insecticides Insecticide soil residue analysis at different periods after applications indicated slower insecticide dissipation and release rates on treated soil for all solid applied insecticides in comparison with liquid applied insecticides. For instance, residue results showed liquid applied lambda-cyhalothrin concentration on soil rapidly reducing over time, starting with a concentration of 580 ng g − 1 at 1 DAA, to 230 ng g − 1 at 14 DAA, representing a 60.3% reduction from its initial concentration at 1 DAA, while solid applied lambda-cyhalothrin concentrations were slightly reduced in a 14 days period, from 265 to 245 ng g − 1 , a 7.5% concentration reduction (Table 4 ). Thiamethoxam concentrations on soil samples followed the same pattern. Liquid thiamethoxam application treatment had high insecticide concentrations in soil shortly after application (1 DAA) with 1560 ng g − 1 , but it was quickly reduced 14 days after to 710 ng g − 1 , a 54.5% reduction from its initial concentration. Solid application of thiamethoxam, however, provided a slower decrease on its initial concentration after a 14 days span with a 38.1% reduction (Table 4 ). Imidacloprid application, on the other hand, showed similar concentration decline for both application methods. Although solid applied imidacloprid treatment had higher initial and final concentrations than the liquid applied treatment on soil at 1 and 14 DAA, respectively, both treatments showed concentration reductions close to 66% from 1 to 14 DAA. Table 4 Mean determination of insecticide residues (ng/g; dry weight) using QuEChERS sample preparation and LC-MS/MS and Gas Chromatography of soil samples from each insecticide treatment at three periods after application Insecticide Application Method 1 DAA 7 DAA 14 DAA Residue (ng g − 1 ) Residue (ng g − 1 ) Residue (ng g − 1 ) lambda-cyhalothrin liquid 580 280 230 lambda-cyhalothrin solid 265 255 245 thiamethoxam liquid 1560 1055 710 thiamethoxam solid 1875 1315 1160 imidacloprid liquid 35 20 12 imidacloprid solid 45.5 36.5 15.5 Insecticide efficacy results showed that adults of S. levis exposed to treated sugarcane 1 day after application (1 DAA) had significant results of control for each evaluation period. At 8 days after insect exposure (8 DAIE) to treated rhizome and soil, application treatments were significant to affect percentage of dead and moribund insects ( p < 0.0001) as in Fig. 3 . Despite the liquid application of lambda-cyhalothrin + thiamethoxam (T2) had higher mortality level, 18,7% of S. levis control, it was only significantly higher than T4. Additionally, T2 also presented the greatest level of moribund insects, 23.4%. At 12 days after insect exposure (12 DAIE), S. levis dead and moribund percentage was significantly affected by application treatment ( p = 0.0018 and p = 0.0067, respectively) as in Fig. 3 . The liquid application of lambda-cyhalothrin + thiamethoxam (T2) had higher S. levis control, 34.4%, than the untreated check, but it was not significant different than the solid application of lambda-cyhalothrin + thiamethoxam (T3) and both imidacloprid treatments (T4 and T5). At 12 DAIE, the percentage of moribund insects decreased while the level of dead insects increased for all treatments in comparison with the previous evaluation at 8 DAIE, especially for the lambda-cyhalothrin + thiamethoxam treatments (T2 and T3). At 14 days after insect exposure (14 DAIE), S. levis control was also significantly affected by application treatment ( p = 0.0028 and p = 0.0152) as in Fig. 3 . Such as at 12 DAIE, liquid application of lambda-cyhalothrin + thiamethoxam also had greater insect control than T1 and T4 but was not significantly different from the solid application of the same insecticide (T3) and solid application of imidacloprid (T5). Insects exposed to treated sugarcane and soil 7 days after application (7 DAA) were significantly affected by treatment application. At 8 DAIE, application treatment was not significant to affect S. levis control ( p = 0.2583) but it was significant to affect the percentage of moribund insects ( p < 0.0001) as in Fig. 4 . Both liquid and solid applications of lambda-cyhalothrin + thiamethoxam (T2 and T3) presented greater concentration of moribund S. levis adults than the untreated and the imidacloprid treatments. The T2 treatment had 15.6% while T3 had 17.5% of moribund insects at 8 DAIE. At 12 DAIE, treatments were significant to affect insect control ( p < 0.0001) as in Fig. 4 . The T3 treatments was more effective than the other treatments, except T2, with 41.3% of S. levis control. Despite the percentage of moribund insects at 12 DAIE being reduced in comparison with 8 DAIE, both T2 and T3 had greater levels of moribund insects. For the T3 treatment, for example, the level of moribund insects decreased from 17.5–12.7% while the percentage of dead insects increased from 11.1–41.3% in four days. At 14 DAIE, treatments also impacted significantly the levels of dead insects ( p < 0.0001) but not the concentration of moribund adults ( p = 0.0731). Both T2 and T3 were better effective for S. levis control (40.6 and 52.4%) than the untreated check (T1) and the imidacloprid treatments (T4 and T5). Application treatments on sugarcane 14 days after application were also significant to affect S. levis control. At the evaluation period of 8 DAIE, significant differences across treatments were observed for dead and moribund insects ( p = 0.0004 and p < 0.0001, respectively) (Fig. 5 ). Regarding insect control, the T4 treatment was significantly lower than the remaining treatments while no other differences were observed. The moribund percentage results, however, showed the T3 treatment with the highest concentration, 26.6%, followed by T2 treatment with 15.6%. At 12 DAIE, application treatments were significant to impact insect control and moribund concentration ( p < 0.0001) as in Fig. 5 . The percentage of dead insects increased considerably from 8 to 12 DAIE. In the T3 treatment, it increased from 14–36%. Treatments in the last evaluation period at 14 DAIE also affected significantly ( p < 0.0001) insect control and moribund levels with T3 having greater control values than the remaining treatments, except T2 (Fig. 5 ). Thus, the solid application (T3) had 42.2% of dead adults followed by the liquid application of the same insecticide (T2) with 25%. In addition, both liquid and solid applications of imidacloprid and the untreated check presented less than 10% of S. levis control. To evaluate S. levis control over time after application, results of evaluations at 14 DAIE were analyzed for each period after application (1, 7 and 14 DAA) as in Fig. 6 . Thus, no significant differences of insect control among periods after application were observed for each treatment ( p = 0.5061). However, despite not statically significant, it was possible to notice the liquid application of lambda-cyhalothrin + thiamethoxam (T2) presenting greater insect control at 1 DAA followed by a slight increase on control at 7 DAA and then a substantial decrease at 14 DAA (Fig. 6 ). The T3 treatment, on the other hand, had lower control levels at 1 DAA, followed by a peak on insect control at 7 DAA followed by a percentage decrease at 14 DAA (Fig. 6 ). Analyzing the treatment efficacy in relation to the untreated check (Schneider-Orelli correction formula) for each period after application and evaluation period as in Table 5 , it was possible to observe that for insects exposed to sugarcane and soil at 1 DAA, the highest insecticide efficacy was obtained by the liquid application of lambda-cyhalothrin + thiamethoxam (T2), with maximum efficacy at 14 DAIE (Table 5 ). Sphenophorus levis adults that were exposed to treated soil and sugarcane at 7 DAA were better controlled by the solid application of lambda-cyhalothrin + thiamethoxam (T3) (Table 5 ). Similarly, insects that were exposed to sugarcane and soil treated at 14 DAA were also better controlled by the T3 treatments showing greater treatment efficacy than the other application treatments. As it was also noticed in the percentage of dead insects, the imidacloprid treatments had also extremely low efficacy values. And as observed in Fig. 6 , both T2 and T3 treatment’s efficacy were better achieved on insects exposed to plant/soil at 7 DAA. Table 5 Insecticide application efficacy on Sphenophorus levis control (Schneider-Orelli 1947 ) in relation to the untreated check for each date of insect exposure to treatments (1, 7 and 14 DAA) and at each evaluation period (8, 12 and 14 DAIE) Insecticide Exposure Period Evaluation Period Treatment Efficacy (%) 1 T2 T3 T4 T5 1 DAA 8 DAIE 11.9 0 0 0 12 DAIE 28.8 20.6 1.7 3.4 14 DAIE 29.3 19.2 0 3.4 7 DAA 8 DAIE 1.7 5.2 0 0 12 DAIE 25.4 36.3 0 0 14 DAIE 35.6 48.4 0 0 14 DAA 8 DAIE 11.1 12.7 0 3.2 12 DAIE 12.9 33.9 0 4.8 14 DAIE 20.0 38.3 0 3.3 1 T2 – lambda-cyhalothrin + thiamethoxam liquid applied; T3 - lambda-cyhalothrin + thiamethoxam solid applied; T4 – imidacloprid liquid applied; T5 – imidacloprid solid applied. 3.2. Experiment 2 - Insecticide Rate Comparison in Solid Application In the second experiment comparing two rates of solid applied lambda-cyhalothrin + thiamethoxam it was possible to observe meaningful differences between active ingredient concentrations in soil for both tested rates. The higher insecticide dose at 14 DAA promoted lambda-cyhalothrin concentration in soil of 11665 ng g − 1 , 123% more concentrated than the lower dose of lambda-cyhalothrin with 5230 ng g − 1 (Table 6 ). Meanwhile, doubling insecticide rate for thiamethoxam promoted an increment of 136% more than the recommended rate, from 3310 to 7830 ng g − 1 (Table 6 ). Table 6 Mean determination of insecticide residues (ng/g; dry weight) using QuEChERS sample preparation and LC-MS/MS and Gas Chromatography of soil samples from each solid applied insecticide dose treatment at 14 days after application (DAA) Insecticide Insecticide Rate Residue (ng g − 1 ) lambda-cyhalothrin 1x Dose 5230 lambda-cyhalothrin 2x Dose 11665 thiamethoxam 1x Dose 3310 thiamethoxam 2x Dose 7830 Mortality results were conducted with S. levis adults exposed to insecticide residue on sugarcane and soil at 14 DAA during four evaluation periods. At the first evaluation period, 4 DAIE, treatments were significantly different to affect the concentration of moribund insects ( p = 0.0110) but not to affect the mortality levels ( p = 0.3334) as shown in Fig. 7 . Doubling the insecticide rate significantly increased S. levis control. The higher insecticide dose (double dose) resulted in 67.4% of moribund S. levis adults while the lower dose (recommended dose) provided 40.7% of moribund insects. Less than 6% of insect were dead at 4 DAIE for both doses. At 8 DAIE, treatments were significantly different regarding insect mortality ( p = 0.0287) but were not for moribund insects ( p = 0.2182). The higher insecticide dose provided better S. levis control than the lower dose (Fig. 7 ). Additionally, the percentage of moribund insects decreased substantially while the number of dead insects increased. At 4 DAIE for the double dose treatment, for example, the level of moribund insects was of 67.4% and four days later, at 8 DAIE, it dropped to 21.2%. S. levis control was also significantly affected by treatments at 12 DAIE ( p = 0.0086) while the level of moribund insects was not ( p = 0.9032). The solid application of lambda-cyhalothrin + thiamethoxam with higher insecticide rate had better S. levis control (65.3%) than the lower dose treatment (44%). The percentage of moribund insects decreased even more when compared to the previous evaluation period at 8 DAIE while the level of dead insects increased. Finally, at the last evaluation period of 14 DAIE, significant differences on S. levis control between insecticide doses were detected ( p = 0.0426) with no differences on moribund concentration ( p = 0.2069). The higher dose treatment had better control than the lower dose treatment, 76.7% and 58.8%, respectively (Fig. 7). 4. Discussion 4.1. Experiment 1 - Liquid and Solid Application of Insecticides Results of S. levis adult control indicated low treatment efficacy across all insecticides and application methods, including liquid and solid applications. The maximum percentage for insect control was of only 52.38% with lambda-cyhalothrin + thiamethoxam solid applied at 7 DAA during the last evaluation period (Fig. 4 ) while the maximum treatment efficacy using the correction formula was of 48.4% for the same treatment and period (Table 5 ). According to Health and Safe Executive (HSE) British regulator agency, pest control levels between 40 and 60% are considered to provide some control or to reduce pest damage (HSE 2020), although some regulation agencies may require pest control levels above 80% (Embrapa 2011 ). Similar results have also been reported by different authors regarding low efficacy of insecticides on S. levis control. In one field study evaluating different insecticides for S. levis control, average efficacy was of only 60% (Dinardo-Miranda et al. 2006 ). No success of S. levis control was also observed in another field study testing different insecticides (Alencar 2016 ). In one laboratory experiment, however, the author reported high S. levis adult control efficacy with entomopathogenic nematodes associated with insecticides (Tavares 2006 ), but the adopted methodology in that study consisted of direct treatment applications on sugarcane stalks carrying S. levis adults in it and buried in sand, probably facilitating insecticide translocation and improving control levels. The current experimental methodology, on the other hand, simulated ratoon applications by applying treatments on actual ratoon plants and soil and exposing insects to treated ratoon plants and soil. Even though the current experiment was conducted in a more realistic scenario in comparison to other methodologies, laboratory results are expected to present higher efficacy levels than field trials. For instance, even when highly effective treatments from laboratory results were tested in field, low S. levis controls were still reported (Tavares 2006 ). Laboratory experiment conditions are often controlled and restricted to some standards while field conditions are susceptible to several variables. These field variables can, therefore, impact directly the active ingredient’s degradation, absorption and efficacy. The soil half-life (DT 50 ) of thiamethoxam in laboratory conditions, for example, is of 121 days, while in field conditions it drops to 39 days (Lewis et al. 2016 ). In the present study, however, insecticides concentrations from soil samples at 1 DAA had a reduction of over 50% for all liquid applications of lambda-cyhalothrin, thiamethoxam and imidacloprid after 14 days. Thus, if recommended insecticide rates were not effective against S. levis adults in laboratory, as observed in the present study, field applications may present even worst efficacy levels. In addition, both liquid and solid applications of imidacloprid had low insecticide residues on soil at all evaluation periods and had practically zero S. levis adult control such as the untreated control. Similar results were also reported in a study comparing insecticides and entomopathogenic nematodes for S. levis adult control. In this study, the liquid application of imidacloprid provided less than 10% of S. levis adult mortality (Tavares 2006 ). Hence, based on present results and previous research (Tavares 2006 ; Alencar 2016 ), both solid and liquid application of imidacloprid should not be recommended for S. levis adult control while applications of lambda-cyhalothrin + thiamethoxam showed some potential for S. levis adult control requiring further studies with higher insecticide rates. Present results showed the efficacy of treatments considering residual exposure of adults to insecticides as an attempt to better simulate field reality. However, if treatments were topically tested on S. levis adults, efficacy levels would probably be greater than the ones reported here. But as S. levis is a soil-inhabiting pest, the biology cycle and adult activity takes place predominantly in the soil subsurface (Ferreira 2022) while the minority of S. levis larvae, pupae and adults in field would be directly exposed to insecticide applications. In addition, treatment efficacy values reported here are only valid for adult S. levis control. If treatments were to be tested for larvae/pupae mortality, greater control levels would also be expected. Some granular insecticide labels have, for example, specified at which pest’s life stage the product is recommended to be applied (Anonymous, 2022 ). During the evaluation periods of insect control assessment, it was also possible to observe the progression of insecticide poisoning symptomology on S. levis adults, especially for those exposed to lambda-cyhalothrin + thiamethoxam. During the first evaluations, at eight and twelve days after insects were exposed to the insecticide, the concentration of moribund insects was higher than in the last evaluation period, at 14 DAIE. It was clear that S. levis adults exposed to lambda-cyhalothrin + thiamethoxam were initially affected showing poisoning symptoms like uncoordinated, slow and atypical movement (Online Resource 2). Most insects that showed initial poisoning symptoms were dead by the last evaluation period. The usual symptoms of pyrethroid insecticides, like lambda-cyhalothrin, include convulsive activity, vigorous tremors, incorporated movements, rapid paralysis and death (Nishimura et al. 1987 ; Tomlin 1997 ). Similar uncoordinated movements as those observed on S. levis adults in the experiment were also reported in a study in which authors evaluated pyrethroid symptoms on desert locusts ( Schistocerca gregaria Forskål) (Maccuaig 1980 ). Within few minutes after application, symptoms were evident on desert locusts but were less apparent after two days (Maccuaig 1980 ). However, due to lambda-cyhalothrin’s low solubility (0.005 mg L − 1 ) and extremely high adsorption to organic matter (Koc = 283707) (Lewis et al. 2016 ), the insecticide was probably not available through soil and plant rhizome when S. levis adults were exposed due to organic matter binding of the insecticide. Even though some lambda-cyhalothrin concentration was detected on soil samples the strong sorption and hydrophobic characteristics of lambda-cyhalothrin can affect its bioavailability causing pest control reduction (Oudou and Hansen 2002 ). Therefore, based on physicochemical properties and literature, it is hypothesized that most residual poisoning symptoms on S. levis adults were caused by thiamethoxam toxicity. Thiamethoxam and other neonicotinoid insecticides are also known to induce continuous nervous excitation, loss of coordination and orientation, paralysis, decrease in plant feeding and death, as similarly reported in the present study (Martinou et al. 2014 ; Goulson 2013 ; Yao et al. 2015 ). In an experiment investigating the reduction in feeding and locomotion pattern of carabids ( Platynus assimilis Paykull), it was noticed a significant reduction of food consumption even for insects treated with very low thiamethoxam rates (Tooming et al. 2017 ). In the same study, beetle adults showed similar symptoms of locomotor hypoactivity state after thiamethoxam treatment (Tooming et al. 2017 ). According to thiamethoxam’s physicochemical properties, such as its solubility (4100 mg L − 1 ) and adsorption (Koc = 56.2) (Lewis et al. 2016 ), it is possible to suggest that thiamethoxam was probably more available in soil and for plant uptake (rhizome) with consequent higher exposure on S. levis adults than lambda-cyhalothrin was, regardless of its detected concentrations on soil samples. This characteristic high mobility of thiamethoxam in soil has been previously reported (Mörtl et al. 2016 ). In addition, when associating both the insecticide’s degradation path and insecticide’s efficacies as observed in the present study, it is important to state that low S. levis control can also be related to the adsorption of lambda-cyhalothrin on organic matter or the high mobility of thiamethoxam causing the active ingredient to leach and dilute its concentration within the soil profile. Despite no great levels of insect control, both liquid and solid applications of lambda-cyhalothrin + thiamethoxam were better alternatives to control S. levis adults than the remaining treatments. The results indicated similar S. levis adult control for both liquid and solid application of lambda-cyhalothrin + thiamethoxam, however, it was evident the liquid application (T2) provided higher control levels and efficacy than T3 (Fig. 3 ) when insects were exposed to treatments shortly after application (1 DAA) due to its availability in the soil solution. Pesticides when liquid applied are usually readily available for plant/insect uptake once the active ingredient reaches the soil solution, depending only on the kinetics of dissolution of the active ingredient (Davis et al. 1996 ). Insecticide granules, however, are applied dry and need to be wetted first so the active ingredient is dissipated from the granule into the soil solution for later target absorption (Davis et al. 1996 ). Thus, the liquid treatment (T2), in association with the drip irrigation used on sugarcane pots, had more lambda-cyhalothrin + thiamethoxam initially available for insect exposure than the solid treatment. It was also possible to notice the liquid application efficacy of lambda-cyhalothrin + thiamethoxam and its concentrations decreasing faster over time than the solid treatment which indicates low potential for long-term crop protection (Fig. 6 and Table 5 ). As previously stated, liquid pesticides can quickly dissolve into the soil solution accelerating its availability but also its losses in the environment through biological and chemical degradation, photolysis, evaporation, runoff and leaching (Davis et al. 1996 ; Fernández-Pérez 2007 ). On the other hand, despite not significant different, the solid application of lambda-cyhalothrin + thiamethoxam (T3) had greater S. levis adult control percentage than T2 when insects were exposed to treatments at 7 and 14 DAA demonstrating some potential for long-term insect control. Considering the solid treatment, T3, was not composed by a specific formulation for solid application but by a mixture of two insecticides with different formulations (GR of lambda-cyhalothrin and WG of thiamethoxam), the observed behavior of maximum efficacy at 7 DAA could be highly improved if a proper and adequate GR formulation was used for both active ingredients. Proper granular formulations may include those with controlled release (CR) technologies that can maintain effective control levels during longer and controlled periods (Roy et al. 2014 ). Since the early 1990s, the Australian sugar industry has been working with CR formulations of insecticides aiming the control of canegrubs species in sugarcane (Allsopp 2020 ). More recently, with a newer imidacloprid CR formulation product, trial results have indicated control of different canegrub species from 2 to 4 years using the granular formulated insecticide (Ward 2016 ). In a study developing a CR formulation for imidacloprid, it was observed that both the amount and concentration of the coating membrane of granules had direct effects on release time of the active ingredient (Kimoto et al. 2007 ). The authors also observed the effect of temperature on the insecticide release profile, in which lower temperatures extended the release period (Kimoto et al. 2007 ). Even without an adequate formulation of lambda-cyhalothrin + thiamethoxam, the potential of insecticide solid applications on sugarcane for S. levis adult control was observed in the present study showing prolonged insect control with slower reduction of insecticide residue in soil. As no granular and controlled-release insecticides are currently available for S. levis control in sugarcane, the development of new insecticide formulations should be encouraged by the sugarcane farming community and by the pesticide industry. Moreover, based on the results, it is clear the recommended insecticide rates were not effective to control S. levis adults, thus, new experiments comparing different insecticide rates should be conducted. 4.2. Experiment 2 - Insecticide Rate Comparison in Solid Application As observed in Experiment 1, current insecticide rates were not effective to successfully control S. levis adults. The second experiment considered the treatment with greatest control efficacy from experiment 1, with was the lambda-cyhalothrin + thiamethoxam solid applied (T3), and compared two insecticide rates regarding insecticide concentration analysis in soil and S. levis adult control. The higher dose clearly promoted greater insecticide residue on soil and provided better adult control than the recommended rate at 14 DAIE, giving a maximum control percentage of 76.7% in comparison to 58.8%. Despite potential insecticide losses from different degradation pathways such as leaching, adsorption, microbiological and photodegradation, the greater dose treatment maintained greater concentrations in soil (up to 136% more for thiamethoxam) and rhizome and, as consequence, provided greater insect control. According to the HSE British regulator agency, insect control levels between 60 and 80% can be classified as useful for pest control while levels between 40 and 60% are considered to provide some control or to reduce pest damage (HSE 2020). Thus, doubling the recommended lambda-cyhalothrin + thiamethoxam rate improved S. levis control’s classification as useful for control and improved the mortality levels by 1.3 times. In an experiment evaluating the susceptibility of pepper weevil ( Anthonomus eugenii Cano) to thiamethoxam, for example, the insecticide concentration to provide 50% weevil mortality (LC 50 ) was of 0.53 mg ai L − 1 while the concentration to control 95% of insects (LC 95 ) was 3.6 times higher, 1.91 mg ai L − 1 (Caballero et al. 2015 ). Similarly, studying the toxicity of lambda-cyhalothrin to Asian long horned beetle ( Anoplophora glabripennis Motschulsky), authors reported a dose increment of 5.7 required to change the lethal dose of 50% of insects (LD 50 ) to a 90% (LD 90 ) (Wu et al. 2015). As the experiment was conducted in controlled conditions, including sugarcane plants grown in pots and a confined area (plastic container) for insect exposure to insecticide residue on soil and cane rhizome, observed residue and control results are probably higher than under field conditions. Especially due to intrinsic field variability. Therefore, it is expected that both insecticide residue in soil and S. levis adult control in field applications may present lower concentrations and efficacy in comparison with current laboratory results. Further studies including additional insecticide rates should be conducted to better asses the most effective active ingredient concentration for S. levis adult control. Several authors have evaluated the toxicity profile of different insecticides to a range of agricultural pests but no study has assessed the dose response of insecticides on S. levis control to present date. Some authors have evaluated the lethal dose and concentration of some insecticides on S. venatus vestitus in laboratory bioassays (Doskocil et al. 2012 ). In that study, authors evaluated bifenthrin, imidacloprid and clothianidin insecticide dose responses by topical application on the ventral side of the insect’s thorax (Doskocil et al. 2012 ). Future S. levis laboratory bioassays, however, should consider the insect’s subterranean behavior and should consider applying insecticide treatments directly on soil/plant instead of topical applications as a more realistic scenario. The present study’s bioassay, for example, provides a better representation of field reality by considering the insect behavior and the most probable path of exposure to applied insecticides, the soil and plant rhizome. If the double dose treatment in the present study provided up to 2.3 times more insecticide residue on soil at 14 DAA and promoted control levels up to 76.7%, higher doses may provide greater residues and control results closer to 90 or 100%. As previously stated, several researchers have conducted similar studies for different insects and products (Doskocil et al. 2012 ; Caballero et al. 2015 ; Wu et al. 2015) and new experiments should consider dose-response insecticide effects for S. levis control. However, a cost-effectiveness analysis of higher insecticide rates should also be conducted to evaluate the economic viability of the operation. Although increasing insecticide application rate increases the application cost, potential yield increment through S. levis control may reveal to be economically valid. Evaluating the cost-effectiveness of different granular insecticides for pink stem borer ( Sesamia inferens Walker) control, authors have reported the economic viability of two applications of solid thiamethoxam (WG) in corn ( Zea mays L.) (Sidar et al. 2017 ). Moreover, if precision agriculture tools for insect symptomology mapping is proper used, such as satellite multispectral/hyperspectral imagery and unmanned aerial vehicles (UAVs) photogrammetry, site-specific maps for insecticide applications can be used for spot spraying. By only spraying where S. levis symptoms are detected, the total amount of insecticide to be applied can be drastically reduced in comparison with conventional broadcast/band applications and, therefore, could possibly justify insecticide dose increment. In addition, improved pest control as a result of greater insecticide doses may require less applications and may reduce operational costs in despite of pesticide inputs. The higher insecticide rate results also indicate a great potential for solid applications on S. levis control. As a number of researchers have reported low field efficacies with current insecticides liquid applied for S. levis control (Dinardo-Miranda et al. 2006 ; Tavares 2006 ; Alencar 2016 ), current results are an indication that insecticides solid applied can improve pest control, especially if proper granular formulation is adopted (Roy et al. 2014 ; Ward 2016 ; Allsopp 2020 ). In addition to new studies including more insecticides and different active ingredient concentrations, sequential insecticide applications and other integrated pest management (IPM) alternatives should also be tested for S. levis control potential. Examples of IPM actions should include desiccation and destruction of volunteer cane, bare fallow, crop rotation, seed cane billets of high phytosanitary quality, variety selection, insect baiting, biological control and insecticide’s mode of action rotation. Similar to Experiment 1 results, a great number of moribund adults was detected during earlier insect evaluations (Fig. 7 ) for both treatments. The first evaluation (4 DAIE), especially, had a high number of S. levis adults with symptoms of slow, uncoordinated and uncommon movement (Online Resource 2). By the last evaluation, most insects initially showing poisoning symptoms were diagnosed dead (Fig. 7 ). 5. Conclusions The proposed bioassay methodology simulating S. levis adult control though insecticide exposure after ratoon sugarcane treatments has proven to be effective for S. levis adult control evaluation. Based on the results, low S. levis adult control (< 53%) was achieved with both liquid and solid application of insecticides while solid applications prolonged the residual activity in comparison with liquid ones. Solid and liquid application of lambda-cyhalothrin + thiamethoxam promoted maximum pest control when S. levis adults were exposed to insecticide residues after seven days from the application. Doubling lambda-cyhalothrin + thiamethoxam dose resulted in higher soil residue and greater S. levis adult control (76.7%) in comparison with the recommended labelled dose (58.8%). The application of solid lambda-cyhalothrin + thiamethoxam demonstrated great potential for S. levis adult control in sugarcane but the development of proper granular formulations including higher active ingredient concentration formulations should optimize insecticide performance for S. levis control. Declarations Author Contribution P.H.U.F. performed the study, designed and validated the experiment, analyzed the data, wrote the manuscript, reviewed and edited the manuscript. M.C.F. supervised the study, reviewed and edited the manuscript. E.V. conducted insecticide residue analysis. Funding This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. Data Availability Statement Additional data information is available from the corresponding author, P.H.U.F., upon reasonable request such as datasets generated and/or analyzed during the study. Conflict of Interest The authors declare no competing interests. References Alencar MAV (2016) Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae): caracterização macroscópica e determinação de inseticida e época de aplicação para controle. PhD Thesis in Agricultural Entomology, Universidade Estadual Paulista, Jaboticabal, SP. p. 68. Allsopp PG (2020) IPM for Whitegrubs in Australian Sugarcane: From a Continuing Success to Regressing to the Past. Sugar Tech 23:225-238. doi:10.1007/s12355-020-00904-0 Anastassiades M, Lehotay SJ, tajnbaher D, Schenck FJ (2003) Fast and easy multiresidue method employing acetonitrile extraction/partitioning and “dispersive solid-phase extraction” for the determination of pesticide residues in produce. Journal of AOAC International, 86: 412–431. PMID:12723926 Anonymous (2022) Merit ® 0.5 G insecticide product label. Publication No. 80867190C 161025 AV1. Research Triangle, NC: Bayer Environmental Science. Buhler WG, Gibb TJ (1993) Efficacy of Insecticides on Black Cutworm in Bentgrass, 1992. Insecticide and Acaricide Tests 18: 305-306. Caballero R, Schuster DJ, Smith HA, Mangandi J, Portillo HE (2015) A systemic bioassay to determine susceptibility of the pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) to cyantraniliprole and thiamethoxam. Crop Prot. 72:16-21. doi:doi.org/10.1016/j.cropro.2014.11.002. Casteliani A, Martins LF, Cardoso, JFM, Silva MSO, Silva RSA, Chacon-Orozco JG, Casteliani AGB, Půža V, Harakava R, Leite LG (2020) Behavioral aspects of Sphenophorus levis (Coleoptera: Curculionidae), damage to sugarcane and its natural infection by Steinernema carpocapsae (Nematoda: Rhabditidae). Crop Prot. 137: 105262. doi:doi.org/10.1016/j.cropro.2020.105262. Davis RF, Wauchope RD, Johnson AW, Burgoa B, Pepperman AB (1996) Release of Fenamiphos, Atrazine, and Alachlor into Flowing Water from Granules and Spray Deposits of Conventional and Controlled-Release Formulations. J Agric Food. Chem. 44:2900–2907. Doi:10.1021/jf950131x Degaspari N, Botelho NPS, Almeida LC, Castilho HJ (1987) Biologia de Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae) em dieta artificial e no campo. Pesquisa Agropecuária Brasileira 22: 556-558. Dinardo-Miranda LL, Fracasso JV, Cabral SB, Valério W, Gonçalves RD, Beltrame JÁ (2006) Eficiência de inseticidas aplicados em soqueiras de cana-de-açúcar no controle de Sphenophorus levis. STAB. Açúcar, Álcool e subprodutos, 24: 34-37. Dinardo-Miranda LL, Fracasso JV (2013) Sugarcane straw and the populations of pests and nematoids. Scientia Agricola 70: 305-310 Doskocil JP, Sorenson CE, Royalty RN, Brandenburg RL (2012) Evaluation of Insecticides for Lethal Dose, Lethal Concentration, and Field Activity on Hunting Billbug in Warm-Season Turfgrass. Appl Turfgrass Sci. 9:1–9. doi:10.1094/ATS-2012-0227-01-RV Embrapa (2011) Normas para avaliação e para indicação de inseticidas. In: V Reunião da Comissão Brasileira de Pesquisa de Trigo e Triticale. Regimento, Dourados: Embrapa Agropecuária Oeste: ISBN 978-85-7540-028-9. Fernández-Pérez M (2007) Controlled release systems to prevent the agro-environmental pollution derived from pesticide use. J Environ Sci Health B 42(7):857–862. doi:10.1080/03601230701555138 Ferreira PHU, Ferreira MDC (2023) Sphenophorus levis Behavior Studies: Evaluating Insect Attractiveness or Repellency to One Insecticide Treatment and Assessing Nocturnal Insect Activity and Location Pattern. Insects, 14: 205. doi: 10.3390/insects14020205. PMID: 36835774; PMCID: PMC9962633. Goulson D (2013) An overview of the environmental risks posed by neonicotinoid insecticides. J Appl Ecol. 50:977–987. doi:10.1111/ 1365-2664.12111 HSE, Health and Safety Executive (2020) Efficacy Assessments: UK Product Labelling and National Issues. V. 1.0. July, 2020. https://www.hse.gov.uk/pesticides/pesticides-registration/efficacy-guides/index.htm Kimoto N, Takahashi A, Inubushi K (2007) Design and release profile of timed-release coated granules of systemic insecticide. Journal of Pesticide Science 32: 402-406. Lenth R (2019) Emmeans: Estimated Marginal Means, aka Least-Squares Means. R package v. 1.3.5.1. Lewis KA, Tzilivakis J, Warner D, Green A (2016) An international database for pesticide risk assessments and management. Hum Ecol Risk Assess. 22:1050-1064. doi:10.1080/10807039.2015.1133242 Maccuaig RD (1980) Synthetic Pyrethroid Insecticides: Some Studies with Locusts. Trop Pest Manag. 26:349–354. doi:10.1080/09670878009414915 Martinou AF, Seraphides N, Stavrinides MC (2014) Lethal and behavioral effects of pesticides on the insect predator Macrolophus pygmaeus. Chemosphere 96:167–173. doi.org/10.1016/j.chemosphere.2013.10.024 Moral RA, Hinde J, Demétrio CGB (2017) Half-Normal Plots and Overdispersed Models in R: The hnp Package. J Stat Softw. 81:1–23. Mörtl M, Kereki O, Darvas B, Klátyik S, Vehovszky A, Gyyri J, Székács A (2016) Study on Soil Mobility of Two Neonicotinoid Insecticides. J Chem. 2016:1-9. Article ID 4546584. http://dx.doi.org/10.1155/2016/4546584 Nishimura K, Ohoka M, Fujita T (1987) Quantitative structure-activity studies of pyrethroids: 10. Physicochemical substituent effects of substituted benzyl pyrethrates on symptomatic and neurophysiological activities. Pestic Biochem Phys. 28:257–270. doi:10.1016/0048-3575(87)90024-1 Oudou HC, Hansen HCB (2002) Sorption of lambda-cyhalothrin, cypermethrin, deltamethrin and fenvalerate to quartz, corundum, kaolinite and montmorillonite. Chemosphere 49:1285–1294. doi:10.1016/s0045-6535(02)00507-6 Pandey AK, Kumar M (2020) Species profiling of white grub beetles and evaluation of pre and post sown application of insecticides against white grub infesting soybean. International Journal of Agricultural and Biosystems Engineering 14: 10-14. doi.org/10.6084/m9.figshare.12488975 Pérez KG (2008) Eficiência de iscas tóxicas no controle de adultos de Sphenophorus levis Vaurie (Coleoptera: Curculinidae) em cana-de-açúcar ( Saccharum officinarum L.). MSc Thesis in Entomology. Universidade de São Paulo, Piracicaba, SP. Precetti AACM, Arrigoni EB (1990) Aspectos bioecológicos e controle do besouro Sphenophorus levis Vaurie, 1978 (Coleoptera, Curculionidae) em cana-de-açúcar. Boletim Técnico Copersucar Edição Especial: 1-15. Raij BV, Andrade JC, Cantarella H, Quaggio JA (2001) Análise Química para Avaliação da Fertilidade de Solos Tropicais. Campinas: Instituto Agronômico; p. 285. Roy A, Singh SK, Bajpai J, Bajpai AK (2014) Controlled pesticide release from biodegradable polymers. Cent Eur J Chem. 12:453-469. doi:10.2478/s11532-013-0405-2 RStudio Team (2021) RStudio: Integrated development for R. v. 1.4.1717. RStudio, Inc., Boston, MA. http://www.rstudio.com/. Schneider-Orelli, O (1947). Entomologisches Praktikum. Sauerlander, Aarau, Switzerland. Sidar YK, Deole S, Gajbhiye RK, Nirmal A (2017) To evaluate the bioefficacy of granular insecticide molecules against pink stem borer. J Entomol Zool Stud. 5:1114-1120. Tavares FM (2006) Avaliação de nematóides entomopatogênicos contra o bicudo da cana-de açúcar Sphenophorus levis Vaurie, 1978, e efeito da associação desses agentes com inseticidas químicos. MSc Thesis in Agronomy, Universidade Estadual Paulista, Botucatu, SP. p. 61. Tomlin CDS (1997) A World Compendium: The Pesticide Manual. 11th ed. Farnham, Surrey, UK: British Crop Protection Council; pp 300-302. Tooming E, Merivee E, Must A, Merivee M-I, Sibul I, Nurme K, Williams IH (2017) Behavioural effects of the neonicotinoid insecticide thiamethoxam on the predatory insect Platynus assimilis. Ecotoxicology 26:902-913. doi:10.1007/s10646-017-1820-5 Ward A (2016) Development of controlled release formulations of imidacloprid for canegrub control: final report 2014/006. Indooroopilly, QLD, Australia: Sugar Research Australia Limited. http://hdl.handle.net/11079/17024 Wu J, Smith MT (2015) Lethal Effects of Lambda-Cyhalothrin and its Commercial Formulation on Asian Longhorned Beetle (Coleoptera: Cerambycidae): Implications for Population Suppression, Tree Protection, Eradication, and Containment. J Econ Entomol. 108:150–156. doi.org/10.1093/jee/tou052 Yao F-L, Zheng Y, Zhao J-W, Desneux N, He Y-X, Weng Q-Y (2015) Lethal and sublethal effects of thiamethoxam on the whitefly predator Serangium japonicum (Coleoptera: Coccinellidae) through different exposure routes. Chemosphere 128:49–55. doi:10.1016/j.chemosphere.2015.01.010 Supplementary Files SupplementaryInformation.docx SupplementaryMaterialsNeotropicalEntomologyPedroUrach.rar Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 15 Mar, 2024 Reviewers invited by journal 14 Mar, 2024 Editor invited by journal 13 Mar, 2024 Editor assigned by journal 08 Mar, 2024 First submitted to journal 06 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4018984","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":279560406,"identity":"92c6c0e4-6c54-4983-92e2-037bfbb89ca8","order_by":0,"name":"Pedro Henrique Urach Ferreira","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5ElEQVRIiWNgGAWjYHACAwjFzsD4AEjx8BGvhZmBGcTiYSNFC5sEiCaoxZy9eduHDww29vzNzNsqv+bYybAxMD98dAOPFsueY8UzZzCkJc44zFZ2W3ZbMtBhbMbGOfhcdSPHmJmH4XACw2Ees9uS25iBWnjYpPFquf8GpOW/vTxQS7HktnoitNzgAWk5wLgBqIXx47bDhLVY9qQVM84wSE7ceJitWJpx23EeNmYCfjFnP7yZ4UOFnb3c8eaNH39uq7bnZ29++Bivw5BJoAsZQBGEHxggsxl/EFA9CkbBKBgFIxMAAGB1PlB1k16VAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-1803-4511","institution":"UNESP FCAV: Universidade Estadual Paulista Julio de Mesquita Filho Faculdade de Ciencias Agrarias e Veterinarias","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Pedro","middleName":"Henrique Urach","lastName":"Ferreira","suffix":""},{"id":279560407,"identity":"34688724-36ca-495d-bd9a-6813f5cbfa65","order_by":1,"name":"Marcelo da Costa Ferreira","email":"","orcid":"","institution":"UNESP FCAV: Universidade Estadual Paulista Julio de Mesquita Filho Faculdade de Ciencias Agrarias e Veterinarias","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Marcelo","middleName":"da Costa","lastName":"Ferreira","suffix":""},{"id":279560408,"identity":"d261822a-364b-4727-811f-ba4ce92f9e0d","order_by":2,"name":"Eliane Vieira","email":"","orcid":"","institution":"Instituto Biologico","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Eliane","middleName":"","lastName":"Vieira","suffix":""}],"badges":[],"createdAt":"2024-03-06 02:11:54","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4018984/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4018984/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":52927073,"identity":"5f11b0db-9d2b-4d6e-bccc-a5c7159c0c76","added_by":"auto","created_at":"2024-03-18 18:44:42","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1496687,"visible":true,"origin":"","legend":"\u003cp\u003eMethodology stages for the insecticide efficacy study: planting of sugarcane seedlings (a); drip irrigation (b); sugarcane pots before (c) and after (d) harvesting; ratoon drill (e) and application of liquid and solid insecticides in ratoon plants (f) simulating ratoon drill applications\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/818e216f46afd92882ceb231.png"},{"id":52927078,"identity":"ee24527a-c674-4606-a613-ff101105710e","added_by":"auto","created_at":"2024-03-18 18:44:44","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":945586,"visible":true,"origin":"","legend":"\u003cp\u003eLaboratory methodology stages for the insecticide efficacy study: sugarcane plants (a) and soil (b) were removed at each evaluation date; treated plants and soil were placed in containers (c) with \u003cem\u003eSphenophorus levis\u003c/em\u003e adults placed right after it (d); insects were exposed to treated soil and rhizome (e) for 96 h and were replaced to new containers with sugarcane stalks (f) at every mortality evaluation (g)\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/826218a67f3e675ebd36001e.png"},{"id":52927077,"identity":"ee1c11c9-6087-47ae-936b-57683b2ce49c","added_by":"auto","created_at":"2024-03-18 18:44:44","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":311917,"visible":true,"origin":"","legend":"\u003cp\u003ePercentage of dead and moribund \u003cem\u003eSphenophorus levis\u003c/em\u003e adults exposed to different treatments on sugarcane one day after application (1 DAA) at different evaluation periods. DAIE – Days After Insect Exposure; lamb+tmx – lambda-cyhalothrin + thiamethoxam; imd – imidacloprid; L – liquid applied; S – solid applied; Bars with mean values in each period followed by same lowercase letter indicate no significant difference for dead insects and bars in each period followed by same uppercase letter indicate no significant difference for moribund insects at α=0.05\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/93167a8ba14012b1d37ce750.png"},{"id":52927076,"identity":"bbb1a67e-b1c3-428c-9525-d64046a068c3","added_by":"auto","created_at":"2024-03-18 18:44:43","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":286402,"visible":true,"origin":"","legend":"\u003cp\u003ePercentage of dead and moribund \u003cem\u003eSphenophorus levis\u003c/em\u003e adults exposed to different treatments on sugarcane seven days after application (7 DAA) at different evaluation periods. DAIE – Days After Insect Exposure; lamb+tmx – lambda-cyhalothrin + thiamethoxam; imd – imidacloprid; L – liquid applied; S – solid applied; Bars with mean values in each period followed by same lowercase letter indicate no significant difference for dead insects and bars in each period followed by same uppercase letter indicate no significant difference for moribund insects at α=0.05\u003c/p\u003e","description":"","filename":"Fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/4a0602eaaa176a51ae861476.png"},{"id":52927072,"identity":"eccf4ac0-3e09-42bb-b06f-2b3b5bec9b46","added_by":"auto","created_at":"2024-03-18 18:44:42","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":288283,"visible":true,"origin":"","legend":"\u003cp\u003ePercentage of dead and moribund \u003cem\u003eSphenophorus levis\u003c/em\u003e adults exposed to different treatments on sugarcane fourteen days after application (14 DAA) at different evaluation periods. DAIE – Days After Insect Exposure; lamb+tmx – lambda-cyhalothrin + thiamethoxam; imd – imidacloprid; L – liquid applied; S – solid applied; Bars with mean values in each period followed by same lowercase letter indicate no significant difference for dead insects and bars in each period followed by same uppercase letter indicate no significant difference for moribund insects at α=0.05\u003c/p\u003e","description":"","filename":"Fig5.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/5ac8ff4cf4b65f6e37c5adc3.png"},{"id":52927075,"identity":"0459e3da-9783-4b90-856a-4f48ef1077b3","added_by":"auto","created_at":"2024-03-18 18:44:43","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":266531,"visible":true,"origin":"","legend":"\u003cp\u003eControl of \u003cem\u003eSphenophorus levis\u003c/em\u003eadults, considering dead insects only, exposed to different treatments on sugarcane at 1, 7 and 14 DAA for the evaluation period of 14 DAIE. DAA – Days After Application; DAIE – Days After Insect Exposure; lamb + tmx –lambda-cyhalothrin + thiamethoxam; \u003cem\u003ens\u003c/em\u003e – not significant at α=0.05\u003c/p\u003e","description":"","filename":"Fig6.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/f608f1e2fecce1688f8cc9dd.png"},{"id":52927079,"identity":"6b82cc10-d8f0-4c74-ad1f-6b4a5782dcf3","added_by":"auto","created_at":"2024-03-18 18:44:45","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":251418,"visible":true,"origin":"","legend":"\u003cp\u003ePercentage of dead and moribund \u003cem\u003eSphenophorus levis\u003c/em\u003e adults exposed to two insecticide rates on sugarcane fourteen days after application (14 DAA) at different evaluation periods. DAIE – Days After Insect Exposure; Bars with mean values in each period followed by same lowercase letter indicate no significant difference for dead insects and bars in each period followed by same uppercase letter indicate no significant difference for moribund insects at α=0.05\u003c/p\u003e","description":"","filename":"Fig7.png","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/ee8c9bb92a93b024269317e8.png"},{"id":52927505,"identity":"ae484202-4f42-44a3-bc22-3cb9090e6e03","added_by":"auto","created_at":"2024-03-18 18:52:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4032831,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/fc81e482-d543-4fbe-b0b6-a55ed41ff3b5.pdf"},{"id":52927074,"identity":"17b048b7-6e5b-4288-969c-5f053402deeb","added_by":"auto","created_at":"2024-03-18 18:44:42","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":34685,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/31d92629678dc77dc165eefe.docx"},{"id":52927081,"identity":"f48a4c2c-40c8-46e0-9d24-458a6e8815e7","added_by":"auto","created_at":"2024-03-18 18:44:46","extension":"rar","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":14123145,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterialsNeotropicalEntomologyPedroUrach.rar","url":"https://assets-eu.researchsquare.com/files/rs-4018984/v1/63ab493157189a874f1c4007.rar"}],"financialInterests":"","formattedTitle":"Improving Sphenophorus levis Adult Mortality with Solid Insecticide Applications and Increased Insecticide Dose","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe sugarcane weevil [\u003cem\u003eSphenophorus levis\u003c/em\u003e Vaurie, 1978 (Coleoptera: Curculionidae)] is considered one of the most important pests in sugarcane (\u003cem\u003eSaccharum officinarum\u003c/em\u003e L.) in Brazil. It was first reported in 1977 (Degaspari et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1987\u003c/span\u003e) but had its importance significantly increased in the last twenty years following the shift of cane harvesting system, from manual harvesting of burnt cane to mechanical harvesting of green cane. Burning sugarcane as a harvesting tool had a direct impact on pest control. After the new mechanical harvesting system without burning was implemented, an increase of pest pressure in sugarcane has been noticed, especially for sugarcane borer [\u003cem\u003eDiatraea saccharalis\u003c/em\u003e Fabricius (Lepidoptera: Crambidae)], root spittlebug [\u003cem\u003eMahanarva fimbriolatta\u003c/em\u003e St\u0026aring;l (Hemiptera; Cercopidae] and \u003cem\u003eS. levis\u003c/em\u003e (Dinardo-Miranda and Fracasso \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Since then, \u003cem\u003eS. levis\u003c/em\u003e has caused great and increasing damage for sugarcane growers with losses up to 30 t ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Precetti and Arrigoni, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e1990\u003c/span\u003e). It has been reported, for instance, that every 1% of damage caused by \u003cem\u003eS. levis\u003c/em\u003e resulted in 1% yield loss (Casteliani et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cem\u003eSphenophorus levis\u003c/em\u003e is a soil-inhabiting pest that damages sugarcane plants by larvae feeding the rhizome. Its larvae stage is, on average, 50 days long, followed by the pupae period with mean duration of 12 days while \u003cem\u003eS. levis\u003c/em\u003e adults can live up to 250 days (Degaspari et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1987\u003c/span\u003e; Casteliani et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Females deposit their eggs inside the sugarcane base and rhizome where it hatches and the larvae starts to feed causing the main damage. Larvae\u0026rsquo;s damage in the rhizome is characterized by a white/yellow frass formed inside tunnels. Plant symptoms include leaf yellowing, starting from outer leaves, leaf necrosis, followed by plant death forming yellow/brown patches distributed across the field. Nearly 90% of formed tunnels are opened bellow soil surface and most of rhizome\u0026rsquo;s openings are filled with soil or with the white/yellow frass (Casteliani et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In addition to pest\u0026rsquo;s immature stages hiding inside buried rhizomes, \u003cem\u003eS. levis\u003c/em\u003e adults are also mostly hidden underground as it has been previously observed (Ferreira 2022). Due to the pest\u0026rsquo;s biology and behavior location underneath the soil, it has been extremely difficult to obtain effective control levels of \u003cem\u003eS. levis\u003c/em\u003e. Specific \u003cem\u003eS. levis\u003c/em\u003e management alternatives have been developed in sugarcane farming systems, including the desiccation with herbicides and destruction of volunteer cane, insect baiting and biological and chemical insecticide applications during planting and ratoon treatment. However, despite the development of different methods, low efficacy of control has been achieved, especially in insecticide applications (Dinardo-Miranda et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Tavares \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Alencar \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAmong the insecticide application methods currently being used for \u003cem\u003eS. levis\u003c/em\u003e control, the most common in ratoon treatments is conducted with ratoon drill applicators. This equipment physically opens the rhizome with a drilling disc at each sugarcane row and applies insecticides through a full jet spray in the rhizome aiming to deposit the active ingredient as close as possible to the target. Unfortunately, this method has not been fully effective, possibly due to inaccurate applications and low insecticide residual. In one study evaluating different insecticides for \u003cem\u003eS. levis\u003c/em\u003e control, the mean insecticide efficacy was of only 60% (Dinardo-Miranda et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). In another study comparing several insecticides, no treatment was effective to reduce \u003cem\u003eS. levis\u003c/em\u003e infestation or to improve sugarcane yield in comparison with the untreated control (Alencar, 2006). All insecticides currently being used for \u003cem\u003eS. levis\u003c/em\u003e control are liquid applied through hydraulic nozzles while no solid applications of granular insecticides are used. Meanwhile, several authors have reported pest control benefits when adopting the application of solid insecticides (Buhler and Gibb \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1993\u003c/span\u003e; Roy et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Ward \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Allsopp \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2020\u003c/span\u003e, Pandey and Kumar \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Granular applications of imidacloprid with controlled-release technology, for example, have provided up to 4 years of satisfactory canegrub control (Ward \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Granular insecticides may improve \u003cem\u003eS. levis\u003c/em\u003e control through the gradual release of the active ingredient concentrated on a granule to the soil profile and for plant uptake. In addition, insecticide concentrations being gradually released underneath the soil could enhance insect control especially due to the gregarious characteristic of this and other Curculionidae species.\u003c/p\u003e \u003cp\u003eMoreover, considering the low efficacy of current insecticides, dose-response studies comparing different product concentrations should be conducted to evaluate if recommended rates are in fact effective or not for \u003cem\u003eS. levis\u003c/em\u003e control. Studying the lethal concentration of different insecticides for hunting billbug (\u003cem\u003eSphenophorus venatus vestitus\u003c/em\u003e Chittenden) control, for example, authors reported it was necessary 6.4 times more insecticide concentration to provide 95% billbug mortality (LC\u003csub\u003e95\u003c/sub\u003e) compared to the concentration required to control 50% of insects (LC\u003csub\u003e50\u003c/sub\u003e) (Doskocil et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2012\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDue to ineffective \u003cem\u003eS. levis\u003c/em\u003e control with current insecticide application methods and recommended product rates, the present study aimed to evaluate the efficacy of two insecticides products (lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam and imidacloprid) applied through solid and liquid application and to compare two insecticide rates (recommended and double dose) on \u003cem\u003eS. levis\u003c/em\u003e adult control through a novel bioassay methodology.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Experiment 1 \u0026ndash; Liquid and Solid Application of Insecticides\u003c/h2\u003e \u003cp\u003eAn insecticide efficacy study in ratoon sugarcane for \u003cem\u003eS. levis\u003c/em\u003e adult control was conducted in 2021 in Jaboticabal, SP, Brazil. The experiment was conducted in a factorial arrangement of treatments (three efficacy evaluation dates by five application treatments) in a completely randomized design with four replications. The experiment was performed in duplicate with insecticide treatment applications on May 27th and June 8th, respectively.\u003c/p\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003e2.1.1. Sugarcane plants\u003c/h2\u003e \u003cp\u003eSeedlings of sugarcane variety CTC 4 (Centro de Tecnologia Canavieira S.A., Piracicaba, SP, Brazil) were planted on November 19th, 2020, in 50 L pots of 0.44 m\u003csup\u003e2\u003c/sup\u003e diameter containing a mixture of soil, sand and manure in a proportion mix of 3:1:1, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). Pot mixture was sent for soil analysis at the Soil Fertility Laboratory at UNESP following known methodology (Raij et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2001\u003c/span\u003e) for organic matter content (14 g dm\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e) cation exchange capacity (73 mmol\u003csub\u003ec\u003c/sub\u003e dm\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e), base saturation (81%) and soil pH (6.0). Sugarcane pots were continuously watered through drip irrigation (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb) with 10 mm of water per day. On April 29th, 162 days after planting, sugarcane plants of the first experiment duplicate were manually harvested (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed). Harvesting was conducted to induce sugarcane ratoon shoots and tillering. On May 13th, the second experiment duplicate was harvested. All plant residue (dry leaves) from each pot was placed on the soil surface of the corresponding harvested pot. The average amount of residue was of 220 g per sugarcane pot (5,000.0 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003e2.1.2. Treatment Application\u003c/h2\u003e \u003cp\u003eInsecticide treatment application was conducted on ratoon sugarcane plants 28 days after harvesting. The first and second experiment duplicates had insecticide treatments applied on May 27th and June 8th, respectively. As the experiment aimed to simulate ratoon drill application of insecticides in field, ratoon cane plants in each pot were manually cut using a small size axe. A vertical and uniform drill depth of 10 cm was ensured using a 30 cm rule (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee). As in field ratoon applications, in which insecticides are applied right after a drilling disc mechanically opens sugarcane tillers and rhizomes, experiment treatments were applied in the same manner after manual drilling. Two insecticides were used with two application methods (solid and liquid application) and one untreated check as in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Insecticide dose was calculated based on the average surface area of sugarcane cylindrical pots, 0.44 m\u003csup\u003e2\u003c/sup\u003e, and the recommended dose of each insecticide in grams per hectare (g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) following the Eq.\u0026nbsp;1 (Eq.\u0026nbsp;1) where \u003cem\u003eCID\u003c/em\u003e is the Calculated Insecticide Dose given in g per treated pot and \u003cem\u003eRCPD\u003c/em\u003e is the Recommended Commercial Product Dose given in g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e:\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eInsecticide application treatments including insecticides, trade names, dose, and active ingredient application rate\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApplication treatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTrade name\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDose\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ea.i. Rate\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eL or kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1 - untreated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e---------\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e---------\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e---------\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT2 - liquid - lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003csup\u003e1\u003c/sup\u003eEngeo Pleno\u0026trade; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.0 L ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e212\u0026thinsp;+\u0026thinsp;282\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT3 - solid - lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003eKaiso Sorbie BR GR\u0026thinsp;+\u0026thinsp;\u003csup\u003e1\u003c/sup\u003eActara\u0026reg; 250 WG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.883\u0026thinsp;+\u0026thinsp;1.128\u003c/p\u003e \u003cp\u003ekg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e212\u0026thinsp;+\u0026thinsp;282\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT4 - liquid - imidacloprid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003csup\u003e3\u003c/sup\u003eWarrant\u0026reg; 700 WG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.5 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1200\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT5 - solid - imidacloprid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWarrant\u0026reg; 700 WG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.5 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1200\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e1\u003c/sup\u003eSyngenta, Basel, Switzerland; \u003csup\u003e2\u003c/sup\u003eNufarm Limited, Laverton North, VIC, Australia; \u003csup\u003e3\u003c/sup\u003eFMC Qu\u0026iacute;mica do Brasil Ltda, SP, Brazil.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cdiv id=\"Equa\" class=\"Equation\"\u003e \u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$CID=\\frac{0.44 x RCPD}{10000}\\text{ }\\text{ }\\text{ }\\text{ }\\text{(1)}$$\u003c/div\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003eLiquid treatments were applied adopting an application water volume of 200 L ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and using a 10 mL syringe size that was constantly pressed towards the entire rhizome cut and pot diameter (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef). Solid treatments were manually applied inside the whole plant fissure ensuring uniform granular application (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef).\u003c/p\u003e \u003cp\u003eAir temperature and relative humidity were measured during insecticide treatment applications with a digital thermo hygrometer Jprolab (JProlab, S\u0026atilde;o Jos\u0026eacute; dos Pinhais, PR, Brazil). Pot subsurface soil temperature was measured with a digital thermometer TE-400 (Instrutherm, S\u0026atilde;o Paulo, SP, Brazil) and soil humidity was assessed with a ph-2500 pH/soil humidity meter (Instrutherm, S\u0026atilde;o Paulo, SP, Brazil). Daily meteorological data including the entire study period was received from the Processing, Automatization and Instrumentalization Laboratory (LIAP) at the Exact Sciences and Engineering Department at FCAV/UNESP, Jaboticabal, SP, Brazil. The data was obtained from an automatic weather station (Davis Instruments, Hayward, CA, USA) closely installed to the study area in the LIAP premises. Average meteorological and soil conditions during application are available in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and additional data of mean rainfall and temperature during the study period is available in the Online Resource 1.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHarvest date, meteorological and soil conditions of each duplicate in experiment 1\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDuplicate 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDuplicate 2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHarvest date\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29/04/2021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13/05/2021\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment application date\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27/05/2021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e08/06/2021\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTemperature (\u0026deg;C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRelative humidity (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e67.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoil temperature (\u0026deg;C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoil humidity (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFirst rain after application / rain amount\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 DAA / 24.8 mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 DAA / 24.8 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.1.3. Plant and Soil Removal\u003c/h2\u003e \u003cp\u003eTreated sugarcane rhizome, tiller and soil were removed for insect exposure and residue evaluation in three different dates including 1 day after application (DAA), 7 and 14 DAA. In each insect exposure period, sugarcane rhizomes were manually extracted from all pots with a grubbing hoe (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). Extracted plants were manually chopped in small pieces (6 cm) using a machete and were placed in individual plastic bags. A uniform amount of treated soil (265 g) was collected from the 5 cm surface of each pot and was placed in identified individual plastic bags. To avoid any source of contamination during plant and soil removal, both grubbing hoe and machete were washed with water and soap between each pot extraction procedure.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.1.4. Insects\u003c/h2\u003e \u003cp\u003e \u003cem\u003eSphenophorus levis\u003c/em\u003e adults used in the mortality evaluations of the experiment were collected between March and May of 2021 in sugarcane fields with previous infestation history and no insecticide application in the year. Sugarcane stalks cut in half (30 cm) were used as \u003cem\u003eS. levis\u003c/em\u003e baits. Following an adapted methodology (P\u0026eacute;rez \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2008\u003c/span\u003e), cane stalks were immersed in 50 L water containers with 10% of melted sugar solution for 24 h. The following day, cane baits were distributed in sugarcane fields with the stalk cut in half section facing the soil and were covered with sugarcane residue. Five days after bait distribution, \u003cem\u003eS. levis\u003c/em\u003e adults found in baits were collected and placed in containers with cane stalks in it. Collected insects were maintained in rectangular plastic containers (15 cm x 11 cm x 6 cm) sealed with small punctured lids for air exchange. In each container 30 adults of \u003cem\u003eS. levis\u003c/em\u003e were placed with 3 cane stalks cut in half (14 cm). Containers were cleaned with soap and 70% ethyl alcohol and sugarcane stalks were replaced every four days. Insects were maintained under 12 h photoperiod, at room temperature (23.2\u0026deg;C\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5) and relative humidity (65% \u0026plusmn; 12) until were used in the insecticide efficacy study. Room temperature and relative humidity were measured with a digital thermo hygrometer Jprolab (JProlab, S\u0026atilde;o Jos\u0026eacute; dos Pinhais, PR, Brazil).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.1.5. Insecticide Soil Residue Analysis\u003c/h2\u003e \u003cp\u003eSoil samples (265 g) that were collected from the 5 cm surface of each pot were stored in plastic bags (-20\u0026deg;C) in complete darkness and were transported in thermal boxes to the Agrochemicals Ecology Laboratory from the Biological Institute at S\u0026atilde;o Paulo, SP, Brazil. For each experiment duplicate, individual soil samples of each pot and treatment were then air-dried at ambient conditions, homogenized, sieved at 2 mm mesh size and stored in plastic bag (-20\u0026ordm;C) in complete darkness prior to extraction and analysis. The extraction procedure was based on QuEChERS (quick, easy, cheap, rugged and safe) method (Anastassiades et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). A dried soil sample (10 g) was placed in a 50 mL polypropylene centrifugation tube and rehydrated with 2 mL distilled water. Then the samples were mixed manually for 30 seconds. Subsequently, 2 g of sodium acetate and 20 mL of acetonitrile containing 1% acetic acid (ACN 1% HAc; extraction solvent) was added. The tube with this mixture was agitated vigorously for 5 minutes, after which, 2 g of sodium chloride and 8 g of magnesium sulfate were added to the tube and again agitated vigorously for 5 min. The tube was then shaken for 30 minutes in an agitator and it was centrifuged for 5 minutes at 3000 rpm. 6 mL of supernatant was transferred to a 15 mL polyethylene tube with 900 mg of anhydrous MgSO4, and 300 mg of PSA. The tubes were mixed manually for 1 minute and centrifuged at 3000 rpm for 5 minutes. The supernatant was filtered through a 0.22 um filter membrane. Imidacloprid and thiamethoxam were analyzed in a liquid chromatography-tandem mass spectrometry Shimadzu 40DXS HPLC (Shimadzu Corporation, Kyoto, Japan) coupled to a Shimadzu 8050 Triple Quad-LC-MS/MS (Shimadzu Corporation, Kyoto, Japan). Chromatographic separation was performed on a Shim-pack Velox C18 of 2.7 \u0026micro;m \u0026times; 2.1 mm \u0026times; 100 mm (Shimadzu Corporation, Kyoto, Japan). Mobile phase A was 5 mmol L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e ammonium acetate-water, mobile phase B was 5 mmol L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e ammonium acetate-methanol at a constant flow rate of 0.3 mL min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The optimized gradient program was 3% of B (initial conditions) for 1.5 minutes, after a linear gradient up to 95% of B in 8.75 minutes and finally, the mobile phase came back to the initial conditions (3% B) at 8.76 minutes. The total run time was 10 minutes and the injection volume was 10 \u0026micro;L. The HPLC was coupled to a MS/MS with an ESI source, operating with positive and negative ionization modes. Nitrogen was used as the nebulizer gas and argon as the collision gas.\u003c/p\u003e \u003cp\u003eLambda cyhalothrin was analyzed with Agilent 7890 Gas Chromatograph (Agilent Technologies, Santa Clara, CA, USA) equipped with an electron capture detector (ECD) 320\u0026ordm;C. A HP-5MS (30 m \u0026times; 0.320 mm \u0026times; 0.25 \u0026micro;m) (Agilent Technologies, Santa Clara, CA, USA) capillary column was used. The temperature program was as follows: primary temperature, 100\u0026deg;C held for 1 min, then increased with the rate of 10\u0026deg;C/min to 280\u0026deg;C. The injection port temperature was set at 230\u0026deg;C and a volume of 1 \u0026micro;L was injected in a splitless mode.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.1.6. Insecticide Efficacy for \u003cem\u003eS. levis\u003c/em\u003e control\u003c/h2\u003e \u003cp\u003eCane rhizomes, tillers and soil that were removed from each treated pot and placed in individual bags were weighed with a GF-1000 precision scale (A\u0026amp;D Company, Limited, Tokyo, Japan). 50 g of treated soil and 85 g of chopped rhizomes, with average length of 6 cm, from each pot were placed in 1 L round containers. Four \u003cem\u003eS. levis\u003c/em\u003e adults were then placed in each round container for treatment exposure. One treated sugarcane pot was used to fill two containers with soil, rhizome and insects. The containers were maintained in a laboratory room with 12 h of photoperiod, room temperature (22.0\u0026deg;C\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3) and relative humidity (64% \u0026plusmn; 7).\u003c/p\u003e \u003cp\u003eAfter 96 hours of \u003cem\u003eS. levis\u003c/em\u003e insect\u0026rsquo;s initial exposure to treated soil and rhizomes, insects were replaced to new 1 L containers with one half sliced cane stalk inside it, with average weight of 40 g and 10 cm long. These new containers were now filled with eight insects from two containers with soil and rhizome of the same treated pot. Thus, each new container had 8 insects that were in contact with treated soil and rhizome of the same individual sugarcane pot. Insects were kept inside the new containers with cane stalks for 96 h until the first mortality evaluation.\u003c/p\u003e \u003cp\u003eThe mortality evaluation consisted of counting the number of live, moribund and dead \u003cem\u003eS. levis\u003c/em\u003e adults in each container. As \u003cem\u003eS. levis\u003c/em\u003e exhibits the behavior of thanatosis, insects were considered dead when no movement was noticed during one minute and when no movement was observed after an involuntary reflex was induced (slight grasp in the abdomen with entomology forceps). Insects were considered live when vigorous and expected movement (insect walking; movement of legs, antenna and head) were observed. The insects assessed as moribund were either lying on their back, even after flipping the insects over, or had an atypical slow and uncoordinated body-part movement. There was a total of three insect control evaluations dates including at 8 days, at 12 days and at 14 days after insect exposure (DAIE) to treated soil and rhizomes. At every mortality evaluation, live and moribund insects were replaced to new containers with half sliced cane stalk. Dead \u003cem\u003eS. levis\u003c/em\u003e adults were discarded.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Experiment 2 \u0026ndash; Insecticide Rate Comparison in Solid Application\u003c/h2\u003e \u003cp\u003eA second insecticide efficacy experiment was conducted. The experiment aimed to evaluate solid application efficacy of one insecticide mixture at two rates. The insecticide mixture consisted of lambda-cyhalothrin (Kaiso Sorbie BR GR, Nufarm Limited, Laverton North, VIC, Australia) with thiamethoxam (Actara\u0026reg; 250 WG, Syngenta, Basel, Switzerland). Treatments included granular lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam at two rates: 212\u0026thinsp;+\u0026thinsp;282 and 424\u0026thinsp;+\u0026thinsp;564 g a.i. ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively. All experiment methodology steps (planting, harvesting, treatment application, plant/soil removal, insecticide residue analysis and laboratory work) were conducted as previously described in Experiment 1. Harvesting was conducted on May 13th and treatment applications on ratoon cane of first and second duplicates were made on August 13th and August 26th, respectively. The only differences between methodologies were that in Experiment 2 only one period of soil/rhizome removal and insect exposure (14 DAA) was adopted, a total of eight round containers with twelve \u003cem\u003eS. levis\u003c/em\u003e adults were used for each insecticide rate and four evaluation periods were conducted including 4, 8, 12 and 14 days after insect exposure (DAIE) to treated soil and rhizomes. Average meteorological and soil conditions during application are available in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and additional data of mean rainfall and temperature during the study period is available in the Online Resource 1.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHarvest date, meteorological and soil conditions of each duplicate in experiment 2\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDuplicate 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDuplicate 2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHarvest date\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13/05/2021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13/05/2021\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment application date\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13/08/2021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26/08/2021\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTemperature (\u0026deg;C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRelative humidity (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoil temperature (\u0026deg;C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoil humidity (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e56.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFirst rain after application / rain amount\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 DAA / 4.2 mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Data analysis\u003c/h2\u003e \u003cp\u003eDescriptive analysis and model fitness were conducted in RStudio Version 1.4.1717 software (RStudioTeam 2021) for the dependent variables of dead and moribund \u003cem\u003eS. levis\u003c/em\u003e adults. Before selection of the best model, different model error distributions and link functions were tested and adjusted to correct for overdispersion and assess goodness of fit. To select the best model, model\u0026rsquo;s performances were compared by half-normal plots with simulation envelopes using the hnp package in R software (Moral et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). \u003cem\u003eSphenophorus levis\u003c/em\u003e mortality and moribund percentage data of each period after application and each evaluation date was treated as dependent variable in a quasibinomial generalized linear model with application treatment as the independent variable in experiment 1 and with insecticide rate as the independent variable in experiment 2. After model selection, results of \u003cem\u003eS. levis\u003c/em\u003e mortality and moribund percentage were submitted to an analysis of deviance (type II Wald chi-square tests) for main effects. Significant effects were analyzed using the emmeans package with Sidak\u0026rsquo;s test at \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 (Lenth \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) to determine significant differences between treatments. Treatment efficacy was calculated using Schneider-Orelli\u0026rsquo;s correction formula (Schneider-Orelli \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e1947\u003c/span\u003e) in which it considers both mortality of treated and untreated mean values in its equation.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec13\"\u003e\n \u003ch2\u003e3.1. Experiment 1 - Liquid and Solid Application of Insecticides\u003c/h2\u003e\n \u003cp\u003eInsecticide soil residue analysis at different periods after applications indicated slower insecticide dissipation and release rates on treated soil for all solid applied insecticides in comparison with liquid applied insecticides. For instance, residue results showed liquid applied lambda-cyhalothrin concentration on soil rapidly reducing over time, starting with a concentration of 580 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 1 DAA, to 230 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 14 DAA, representing a 60.3% reduction from its initial concentration at 1 DAA, while solid applied lambda-cyhalothrin concentrations were slightly reduced in a 14 days period, from 265 to 245 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, a 7.5% concentration reduction (Table\u0026nbsp;\u003cspan\u003e4\u003c/span\u003e). Thiamethoxam concentrations on soil samples followed the same pattern. Liquid thiamethoxam application treatment had high insecticide concentrations in soil shortly after application (1 DAA) with 1560 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, but it was quickly reduced 14 days after to 710 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, a 54.5% reduction from its initial concentration. Solid application of thiamethoxam, however, provided a slower decrease on its initial concentration after a 14 days span with a 38.1% reduction (Table\u0026nbsp;\u003cspan\u003e4\u003c/span\u003e). Imidacloprid application, on the other hand, showed similar concentration decline for both application methods. Although solid applied imidacloprid treatment had higher initial and final concentrations than the liquid applied treatment on soil at 1 and 14 DAA, respectively, both treatments showed concentration reductions close to 66% from 1 to 14 DAA.\u003c/p\u003e\n \u003cdiv\u003e\n \u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 4\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eMean determination of insecticide residues (ng/g; dry weight) using QuEChERS sample preparation and LC-MS/MS and Gas Chromatography of soil samples from each insecticide treatment at three periods after application\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eInsecticide\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eApplication Method\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e1 DAA\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e7 DAA\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e14 DAA\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eResidue\u003c/p\u003e\n \u003cp\u003e(ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eResidue\u003c/p\u003e\n \u003cp\u003e(ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eResidue\u003c/p\u003e\n \u003cp\u003e(ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003elambda-cyhalothrin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eliquid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e580\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e280\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e230\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003elambda-cyhalothrin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esolid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e265\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e255\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e245\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ethiamethoxam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eliquid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1560\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1055\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e710\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ethiamethoxam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esolid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1875\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1315\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1160\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eimidacloprid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eliquid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eimidacloprid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esolid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e45.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eInsecticide efficacy results showed that adults of \u003cem\u003eS. levis\u003c/em\u003e exposed to treated sugarcane 1 day after application (1 DAA) had significant results of control for each evaluation period. At 8 days after insect exposure (8 DAIE) to treated rhizome and soil, application treatments were significant to affect percentage of dead and moribund insects (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) as in Fig.\u0026nbsp;\u003cspan\u003e3\u003c/span\u003e. Despite the liquid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T2) had higher mortality level, 18,7% of \u003cem\u003eS. levis\u003c/em\u003e control, it was only significantly higher than T4. Additionally, T2 also presented the greatest level of moribund insects, 23.4%. At 12 days after insect exposure (12 DAIE), \u003cem\u003eS. levis\u003c/em\u003e dead and moribund percentage was significantly affected by application treatment (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0018 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0067, respectively) as in Fig.\u0026nbsp;\u003cspan\u003e3\u003c/span\u003e. The liquid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T2) had higher \u003cem\u003eS. levis\u003c/em\u003e control, 34.4%, than the untreated check, but it was not significant different than the solid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T3) and both imidacloprid treatments (T4 and T5). At 12 DAIE, the percentage of moribund insects decreased while the level of dead insects increased for all treatments in comparison with the previous evaluation at 8 DAIE, especially for the lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam treatments (T2 and T3). At 14 days after insect exposure (14 DAIE), \u003cem\u003eS. levis\u003c/em\u003e control was also significantly affected by application treatment (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0028 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0152) as in Fig.\u0026nbsp;\u003cspan\u003e3\u003c/span\u003e. Such as at 12 DAIE, liquid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam also had greater insect control than T1 and T4 but was not significantly different from the solid application of the same insecticide (T3) and solid application of imidacloprid (T5).\u003c/p\u003e\n \u003cp\u003eInsects exposed to treated sugarcane and soil 7 days after application (7 DAA) were significantly affected by treatment application. At 8 DAIE, application treatment was not significant to affect \u003cem\u003eS. levis\u003c/em\u003e control (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.2583) but it was significant to affect the percentage of moribund insects (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) as in Fig.\u0026nbsp;\u003cspan\u003e4\u003c/span\u003e. Both liquid and solid applications of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T2 and T3) presented greater concentration of moribund \u003cem\u003eS. levis\u003c/em\u003e adults than the untreated and the imidacloprid treatments. The T2 treatment had 15.6% while T3 had 17.5% of moribund insects at 8 DAIE.\u003c/p\u003e\n \u003cp\u003eAt 12 DAIE, treatments were significant to affect insect control (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) as in Fig.\u0026nbsp;\u003cspan\u003e4\u003c/span\u003e. The T3 treatments was more effective than the other treatments, except T2, with 41.3% of \u003cem\u003eS. levis\u003c/em\u003e control. Despite the percentage of moribund insects at 12 DAIE being reduced in comparison with 8 DAIE, both T2 and T3 had greater levels of moribund insects. For the T3 treatment, for example, the level of moribund insects decreased from 17.5\u0026ndash;12.7% while the percentage of dead insects increased from 11.1\u0026ndash;41.3% in four days. At 14 DAIE, treatments also impacted significantly the levels of dead insects (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) but not the concentration of moribund adults (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0731). Both T2 and T3 were better effective for \u003cem\u003eS. levis\u003c/em\u003e control (40.6 and 52.4%) than the untreated check (T1) and the imidacloprid treatments (T4 and T5).\u003c/p\u003e\n \u003cp\u003eApplication treatments on sugarcane 14 days after application were also significant to affect \u003cem\u003eS. levis\u003c/em\u003e control. At the evaluation period of 8 DAIE, significant differences across treatments were observed for dead and moribund insects (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0004 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, respectively) (Fig.\u0026nbsp;\u003cspan\u003e5\u003c/span\u003e). Regarding insect control, the T4 treatment was significantly lower than the remaining treatments while no other differences were observed. The moribund percentage results, however, showed the T3 treatment with the highest concentration, 26.6%, followed by T2 treatment with 15.6%. At 12 DAIE, application treatments were significant to impact insect control and moribund concentration (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) as in Fig.\u0026nbsp;\u003cspan\u003e5\u003c/span\u003e. The percentage of dead insects increased considerably from 8 to 12 DAIE. In the T3 treatment, it increased from 14\u0026ndash;36%. Treatments in the last evaluation period at 14 DAIE also affected significantly (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) insect control and moribund levels with T3 having greater control values than the remaining treatments, except T2 (Fig.\u0026nbsp;\u003cspan\u003e5\u003c/span\u003e). Thus, the solid application (T3) had 42.2% of dead adults followed by the liquid application of the same insecticide (T2) with 25%. In addition, both liquid and solid applications of imidacloprid and the untreated check presented less than 10% of \u003cem\u003eS. levis\u003c/em\u003e control.\u003c/p\u003e\n \u003cp\u003eTo evaluate \u003cem\u003eS. levis\u003c/em\u003e control over time after application, results of evaluations at 14 DAIE were analyzed for each period after application (1, 7 and 14 DAA) as in Fig.\u0026nbsp;\u003cspan\u003e6\u003c/span\u003e. Thus, no significant differences of insect control among periods after application were observed for each treatment (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.5061). However, despite not statically significant, it was possible to notice the liquid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T2) presenting greater insect control at 1 DAA followed by a slight increase on control at 7 DAA and then a substantial decrease at 14 DAA (Fig.\u0026nbsp;\u003cspan\u003e6\u003c/span\u003e). The T3 treatment, on the other hand, had lower control levels at 1 DAA, followed by a peak on insect control at 7 DAA followed by a percentage decrease at 14 DAA (Fig.\u0026nbsp;\u003cspan\u003e6\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eAnalyzing the treatment efficacy in relation to the untreated check (Schneider-Orelli correction formula) for each period after application and evaluation period as in Table\u0026nbsp;\u003cspan\u003e5\u003c/span\u003e, it was possible to observe that for insects exposed to sugarcane and soil at 1 DAA, the highest insecticide efficacy was obtained by the liquid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T2), with maximum efficacy at 14 DAIE (Table\u0026nbsp;\u003cspan\u003e5\u003c/span\u003e). \u003cem\u003eSphenophorus levis\u003c/em\u003e adults that were exposed to treated soil and sugarcane at 7 DAA were better controlled by the solid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T3) (Table\u0026nbsp;\u003cspan\u003e5\u003c/span\u003e). Similarly, insects that were exposed to sugarcane and soil treated at 14 DAA were also better controlled by the T3 treatments showing greater treatment efficacy than the other application treatments. As it was also noticed in the percentage of dead insects, the imidacloprid treatments had also extremely low efficacy values. And as observed in Fig.\u0026nbsp;\u003cspan\u003e6\u003c/span\u003e, both T2 and T3 treatment\u0026rsquo;s efficacy were better achieved on insects exposed to plant/soil at 7 DAA.\u003c/p\u003e\n \u003cdiv\u003e\n \u003ctable id=\"Tab5\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 5\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eInsecticide application efficacy on \u003cem\u003eSphenophorus levis\u003c/em\u003e control (Schneider-Orelli \u003cspan\u003e1947\u003c/span\u003e) in relation to the untreated check for each date of insect exposure to treatments (1, 7 and 14 DAA) and at each evaluation period (8, 12 and 14 DAIE)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eInsecticide Exposure\u003c/p\u003e\n \u003cp\u003ePeriod\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eEvaluation\u003c/p\u003e\n \u003cp\u003ePeriod\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"4\"\u003e\n \u003cp\u003eTreatment Efficacy (%)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003e1 DAA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e28.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e29.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003e7 DAA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e48.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003e14 DAA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14 DAIE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003e\u003csup\u003e1\u003c/sup\u003eT2 \u0026ndash; lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam liquid applied; T3 - lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam solid applied; T4 \u0026ndash; imidacloprid liquid applied; T5 \u0026ndash; imidacloprid solid applied.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\"\u003e\n \u003ch2\u003e3.2. Experiment 2 - Insecticide Rate Comparison in Solid Application\u003c/h2\u003e\n \u003cp\u003eIn the second experiment comparing two rates of solid applied lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam it was possible to observe meaningful differences between active ingredient concentrations in soil for both tested rates. The higher insecticide dose at 14 DAA promoted lambda-cyhalothrin concentration in soil of 11665 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 123% more concentrated than the lower dose of lambda-cyhalothrin with 5230 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Table\u0026nbsp;\u003cspan\u003e6\u003c/span\u003e). Meanwhile, doubling insecticide rate for thiamethoxam promoted an increment of 136% more than the recommended rate, from 3310 to 7830 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Table\u0026nbsp;\u003cspan\u003e6\u003c/span\u003e).\u003c/p\u003e\n \u003cdiv\u003e\u0026nbsp;\u003ctable id=\"Tab6\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 6\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eMean determination of insecticide residues (ng/g; dry weight) using QuEChERS sample preparation and LC-MS/MS and Gas Chromatography of soil samples from each solid applied insecticide dose treatment at 14 days after application (DAA)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eInsecticide\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eInsecticide Rate\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eResidue\u003c/p\u003e\n \u003cp\u003e(ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003elambda-cyhalothrin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1x Dose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5230\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003elambda-cyhalothrin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2x Dose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e11665\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ethiamethoxam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1x Dose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3310\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ethiamethoxam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2x Dose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7830\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eMortality results were conducted with \u003cem\u003eS. levis\u003c/em\u003e adults exposed to insecticide residue on sugarcane and soil at 14 DAA during four evaluation periods. At the first evaluation period, 4 DAIE, treatments were significantly different to affect the concentration of moribund insects (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0110) but not to affect the mortality levels (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.3334) as shown in Fig. \u003cspan\u003e7\u003c/span\u003e. Doubling the insecticide rate significantly increased \u003cem\u003eS. levis\u003c/em\u003e control. The higher insecticide dose (double dose) resulted in 67.4% of moribund \u003cem\u003eS. levis\u003c/em\u003e adults while the lower dose (recommended dose) provided 40.7% of moribund insects. Less than 6% of insect were dead at 4 DAIE for both doses. At 8 DAIE, treatments were significantly different regarding insect mortality (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0287) but were not for moribund insects (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.2182). The higher insecticide dose provided better \u003cem\u003eS. levis\u003c/em\u003e control than the lower dose (Fig. \u003cspan\u003e7\u003c/span\u003e). Additionally, the percentage of moribund insects decreased substantially while the number of dead insects increased. At 4 DAIE for the double dose treatment, for example, the level of moribund insects was of 67.4% and four days later, at 8 DAIE, it dropped to 21.2%. \u003cem\u003eS. levis\u003c/em\u003e control was also significantly affected by treatments at 12 DAIE (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0086) while the level of moribund insects was not (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.9032). The solid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam with higher insecticide rate had better \u003cem\u003eS. levis\u003c/em\u003e control (65.3%) than the lower dose treatment (44%). The percentage of moribund insects decreased even more when compared to the previous evaluation period at 8 DAIE while the level of dead insects increased. Finally, at the last evaluation period of 14 DAIE, significant differences on \u003cem\u003eS. levis\u003c/em\u003e control between insecticide doses were detected (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0426) with no differences on moribund concentration (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.2069). The higher dose treatment had better control than the lower dose treatment,\u0026nbsp;\u003cstrong\u003e76.7% and 58.8%, respectively (Fig. 7).\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e4.1. Experiment 1 - Liquid and Solid Application of Insecticides\u003c/h2\u003e \u003cp\u003eResults of \u003cem\u003eS. levis\u003c/em\u003e adult control indicated low treatment efficacy across all insecticides and application methods, including liquid and solid applications. The maximum percentage for insect control was of only 52.38% with lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam solid applied at 7 DAA during the last evaluation period (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e) while the maximum treatment efficacy using the correction formula was of 48.4% for the same treatment and period (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). According to Health and Safe Executive (HSE) British regulator agency, pest control levels between 40 and 60% are considered to provide some control or to reduce pest damage (HSE 2020), although some regulation agencies may require pest control levels above 80% (Embrapa \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Similar results have also been reported by different authors regarding low efficacy of insecticides on \u003cem\u003eS. levis\u003c/em\u003e control. In one field study evaluating different insecticides for \u003cem\u003eS. levis\u003c/em\u003e control, average efficacy was of only 60% (Dinardo-Miranda et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). No success of \u003cem\u003eS. levis\u003c/em\u003e control was also observed in another field study testing different insecticides (Alencar \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In one laboratory experiment, however, the author reported high \u003cem\u003eS. levis\u003c/em\u003e adult control efficacy with entomopathogenic nematodes associated with insecticides (Tavares \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), but the adopted methodology in that study consisted of direct treatment applications on sugarcane stalks carrying \u003cem\u003eS. levis\u003c/em\u003e adults in it and buried in sand, probably facilitating insecticide translocation and improving control levels. The current experimental methodology, on the other hand, simulated ratoon applications by applying treatments on actual ratoon plants and soil and exposing insects to treated ratoon plants and soil. Even though the current experiment was conducted in a more realistic scenario in comparison to other methodologies, laboratory results are expected to present higher efficacy levels than field trials. For instance, even when highly effective treatments from laboratory results were tested in field, low \u003cem\u003eS. levis\u003c/em\u003e controls were still reported (Tavares \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Laboratory experiment conditions are often controlled and restricted to some standards while field conditions are susceptible to several variables. These field variables can, therefore, impact directly the active ingredient\u0026rsquo;s degradation, absorption and efficacy. The soil half-life (DT\u003csub\u003e50\u003c/sub\u003e) of thiamethoxam in laboratory conditions, for example, is of 121 days, while in field conditions it drops to 39 days (Lewis et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In the present study, however, insecticides concentrations from soil samples at 1 DAA had a reduction of over 50% for all liquid applications of lambda-cyhalothrin, thiamethoxam and imidacloprid after 14 days. Thus, if recommended insecticide rates were not effective against \u003cem\u003eS. levis\u003c/em\u003e adults in laboratory, as observed in the present study, field applications may present even worst efficacy levels. In addition, both liquid and solid applications of imidacloprid had low insecticide residues on soil at all evaluation periods and had practically zero \u003cem\u003eS. levis\u003c/em\u003e adult control such as the untreated control. Similar results were also reported in a study comparing insecticides and entomopathogenic nematodes for \u003cem\u003eS. levis\u003c/em\u003e adult control. In this study, the liquid application of imidacloprid provided less than 10% of \u003cem\u003eS. levis\u003c/em\u003e adult mortality (Tavares \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Hence, based on present results and previous research (Tavares \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Alencar \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), both solid and liquid application of imidacloprid should not be recommended for \u003cem\u003eS. levis\u003c/em\u003e adult control while applications of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam showed some potential for \u003cem\u003eS. levis\u003c/em\u003e adult control requiring further studies with higher insecticide rates.\u003c/p\u003e \u003cp\u003ePresent results showed the efficacy of treatments considering residual exposure of adults to insecticides as an attempt to better simulate field reality. However, if treatments were topically tested on \u003cem\u003eS. levis\u003c/em\u003e adults, efficacy levels would probably be greater than the ones reported here. But as \u003cem\u003eS. levis\u003c/em\u003e is a soil-inhabiting pest, the biology cycle and adult activity takes place predominantly in the soil subsurface (Ferreira 2022) while the minority of \u003cem\u003eS. levis\u003c/em\u003e larvae, pupae and adults in field would be directly exposed to insecticide applications. In addition, treatment efficacy values reported here are only valid for adult \u003cem\u003eS. levis\u003c/em\u003e control. If treatments were to be tested for larvae/pupae mortality, greater control levels would also be expected. Some granular insecticide labels have, for example, specified at which pest\u0026rsquo;s life stage the product is recommended to be applied (Anonymous, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDuring the evaluation periods of insect control assessment, it was also possible to observe the progression of insecticide poisoning symptomology on \u003cem\u003eS. levis\u003c/em\u003e adults, especially for those exposed to lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam. During the first evaluations, at eight and twelve days after insects were exposed to the insecticide, the concentration of moribund insects was higher than in the last evaluation period, at 14 DAIE. It was clear that \u003cem\u003eS. levis\u003c/em\u003e adults exposed to lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam were initially affected showing poisoning symptoms like uncoordinated, slow and atypical movement (Online Resource 2). Most insects that showed initial poisoning symptoms were dead by the last evaluation period. The usual symptoms of pyrethroid insecticides, like lambda-cyhalothrin, include convulsive activity, vigorous tremors, incorporated movements, rapid paralysis and death (Nishimura et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e1987\u003c/span\u003e; Tomlin \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e1997\u003c/span\u003e). Similar uncoordinated movements as those observed on \u003cem\u003eS. levis\u003c/em\u003e adults in the experiment were also reported in a study in which authors evaluated pyrethroid symptoms on desert locusts (\u003cem\u003eSchistocerca gregaria\u003c/em\u003e Forsk\u0026aring;l) (Maccuaig \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1980\u003c/span\u003e). Within few minutes after application, symptoms were evident on desert locusts but were less apparent after two days (Maccuaig \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1980\u003c/span\u003e). However, due to lambda-cyhalothrin\u0026rsquo;s low solubility (0.005 mg L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and extremely high adsorption to organic matter (Koc\u0026thinsp;=\u0026thinsp;283707) (Lewis et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), the insecticide was probably not available through soil and plant rhizome when \u003cem\u003eS. levis\u003c/em\u003e adults were exposed due to organic matter binding of the insecticide. Even though some lambda-cyhalothrin concentration was detected on soil samples the strong sorption and hydrophobic characteristics of lambda-cyhalothrin can affect its bioavailability causing pest control reduction (Oudou and Hansen \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). Therefore, based on physicochemical properties and literature, it is hypothesized that most residual poisoning symptoms on \u003cem\u003eS. levis\u003c/em\u003e adults were caused by thiamethoxam toxicity. Thiamethoxam and other neonicotinoid insecticides are also known to induce continuous nervous excitation, loss of coordination and orientation, paralysis, decrease in plant feeding and death, as similarly reported in the present study (Martinou et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Goulson \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Yao et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). In an experiment investigating the reduction in feeding and locomotion pattern of carabids (\u003cem\u003ePlatynus assimilis\u003c/em\u003e Paykull), it was noticed a significant reduction of food consumption even for insects treated with very low thiamethoxam rates (Tooming et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). In the same study, beetle adults showed similar symptoms of locomotor hypoactivity state after thiamethoxam treatment (Tooming et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). According to thiamethoxam\u0026rsquo;s physicochemical properties, such as its solubility (4100 mg L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and adsorption (Koc\u0026thinsp;=\u0026thinsp;56.2) (Lewis et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), it is possible to suggest that thiamethoxam was probably more available in soil and for plant uptake (rhizome) with consequent higher exposure on \u003cem\u003eS. levis\u003c/em\u003e adults than lambda-cyhalothrin was, regardless of its detected concentrations on soil samples. This characteristic high mobility of thiamethoxam in soil has been previously reported (M\u0026ouml;rtl et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In addition, when associating both the insecticide\u0026rsquo;s degradation path and insecticide\u0026rsquo;s efficacies as observed in the present study, it is important to state that low \u003cem\u003eS. levis\u003c/em\u003e control can also be related to the adsorption of lambda-cyhalothrin on organic matter or the high mobility of thiamethoxam causing the active ingredient to leach and dilute its concentration within the soil profile.\u003c/p\u003e \u003cp\u003eDespite no great levels of insect control, both liquid and solid applications of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam were better alternatives to control \u003cem\u003eS. levis\u003c/em\u003e adults than the remaining treatments. The results indicated similar \u003cem\u003eS. levis\u003c/em\u003e adult control for both liquid and solid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam, however, it was evident the liquid application (T2) provided higher control levels and efficacy than T3 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) when insects were exposed to treatments shortly after application (1 DAA) due to its availability in the soil solution. Pesticides when liquid applied are usually readily available for plant/insect uptake once the active ingredient reaches the soil solution, depending only on the kinetics of dissolution of the active ingredient (Davis et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). Insecticide granules, however, are applied dry and need to be wetted first so the active ingredient is dissipated from the granule into the soil solution for later target absorption (Davis et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). Thus, the liquid treatment (T2), in association with the drip irrigation used on sugarcane pots, had more lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam initially available for insect exposure than the solid treatment. It was also possible to notice the liquid application efficacy of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam and its concentrations decreasing faster over time than the solid treatment which indicates low potential for long-term crop protection (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). As previously stated, liquid pesticides can quickly dissolve into the soil solution accelerating its availability but also its losses in the environment through biological and chemical degradation, photolysis, evaporation, runoff and leaching (Davis et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1996\u003c/span\u003e; Fern\u0026aacute;ndez-P\u0026eacute;rez \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOn the other hand, despite not significant different, the solid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam (T3) had greater \u003cem\u003eS. levis\u003c/em\u003e adult control percentage than T2 when insects were exposed to treatments at 7 and 14 DAA demonstrating some potential for long-term insect control. Considering the solid treatment, T3, was not composed by a specific formulation for solid application but by a mixture of two insecticides with different formulations (GR of lambda-cyhalothrin and WG of thiamethoxam), the observed behavior of maximum efficacy at 7 DAA could be highly improved if a proper and adequate GR formulation was used for both active ingredients. Proper granular formulations may include those with controlled release (CR) technologies that can maintain effective control levels during longer and controlled periods (Roy et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Since the early 1990s, the Australian sugar industry has been working with CR formulations of insecticides aiming the control of canegrubs species in sugarcane (Allsopp \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). More recently, with a newer imidacloprid CR formulation product, trial results have indicated control of different canegrub species from 2 to 4 years using the granular formulated insecticide (Ward \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In a study developing a CR formulation for imidacloprid, it was observed that both the amount and concentration of the coating membrane of granules had direct effects on release time of the active ingredient (Kimoto et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The authors also observed the effect of temperature on the insecticide release profile, in which lower temperatures extended the release period (Kimoto et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). Even without an adequate formulation of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam, the potential of insecticide solid applications on sugarcane for \u003cem\u003eS. levis\u003c/em\u003e adult control was observed in the present study showing prolonged insect control with slower reduction of insecticide residue in soil. As no granular and controlled-release insecticides are currently available for \u003cem\u003eS. levis\u003c/em\u003e control in sugarcane, the development of new insecticide formulations should be encouraged by the sugarcane farming community and by the pesticide industry. Moreover, based on the results, it is clear the recommended insecticide rates were not effective to control \u003cem\u003eS. levis\u003c/em\u003e adults, thus, new experiments comparing different insecticide rates should be conducted.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e4.2. Experiment 2 - Insecticide Rate Comparison in Solid Application\u003c/h2\u003e \u003cp\u003eAs observed in Experiment 1, current insecticide rates were not effective to successfully control \u003cem\u003eS. levis\u003c/em\u003e adults. The second experiment considered the treatment with greatest control efficacy from experiment 1, with was the lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam solid applied (T3), and compared two insecticide rates regarding insecticide concentration analysis in soil and \u003cem\u003eS. levis\u003c/em\u003e adult control. The higher dose clearly promoted greater insecticide residue on soil and provided better adult control than the recommended rate at 14 DAIE, giving a maximum control percentage of 76.7% in comparison to 58.8%. Despite potential insecticide losses from different degradation pathways such as leaching, adsorption, microbiological and photodegradation, the greater dose treatment maintained greater concentrations in soil (up to 136% more for thiamethoxam) and rhizome and, as consequence, provided greater insect control. According to the HSE British regulator agency, insect control levels between 60 and 80% can be classified as useful for pest control while levels between 40 and 60% are considered to provide some control or to reduce pest damage (HSE 2020). Thus, doubling the recommended lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam rate improved \u003cem\u003eS. levis\u003c/em\u003e control\u0026rsquo;s classification as useful for control and improved the mortality levels by 1.3 times. In an experiment evaluating the susceptibility of pepper weevil (\u003cem\u003eAnthonomus eugenii\u003c/em\u003e Cano) to thiamethoxam, for example, the insecticide concentration to provide 50% weevil mortality (LC\u003csub\u003e50\u003c/sub\u003e) was of 0.53 mg ai L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e while the concentration to control 95% of insects (LC\u003csub\u003e95\u003c/sub\u003e) was 3.6 times higher, 1.91 mg ai L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Caballero et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Similarly, studying the toxicity of lambda-cyhalothrin to Asian long horned beetle (\u003cem\u003eAnoplophora glabripennis\u003c/em\u003e Motschulsky), authors reported a dose increment of 5.7 required to change the lethal dose of 50% of insects (LD\u003csub\u003e50\u003c/sub\u003e) to a 90% (LD\u003csub\u003e90\u003c/sub\u003e) (Wu et al. 2015).\u003c/p\u003e \u003cp\u003eAs the experiment was conducted in controlled conditions, including sugarcane plants grown in pots and a confined area (plastic container) for insect exposure to insecticide residue on soil and cane rhizome, observed residue and control results are probably higher than under field conditions. Especially due to intrinsic field variability. Therefore, it is expected that both insecticide residue in soil and \u003cem\u003eS. levis\u003c/em\u003e adult control in field applications may present lower concentrations and efficacy in comparison with current laboratory results. Further studies including additional insecticide rates should be conducted to better asses the most effective active ingredient concentration for \u003cem\u003eS. levis\u003c/em\u003e adult control. Several authors have evaluated the toxicity profile of different insecticides to a range of agricultural pests but no study has assessed the dose response of insecticides on \u003cem\u003eS. levis\u003c/em\u003e control to present date. Some authors have evaluated the lethal dose and concentration of some insecticides on \u003cem\u003eS. venatus vestitus\u003c/em\u003e in laboratory bioassays (Doskocil et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). In that study, authors evaluated bifenthrin, imidacloprid and clothianidin insecticide dose responses by topical application on the ventral side of the insect\u0026rsquo;s thorax (Doskocil et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Future \u003cem\u003eS. levis\u003c/em\u003e laboratory bioassays, however, should consider the insect\u0026rsquo;s subterranean behavior and should consider applying insecticide treatments directly on soil/plant instead of topical applications as a more realistic scenario. The present study\u0026rsquo;s bioassay, for example, provides a better representation of field reality by considering the insect behavior and the most probable path of exposure to applied insecticides, the soil and plant rhizome.\u003c/p\u003e \u003cp\u003eIf the double dose treatment in the present study provided up to 2.3 times more insecticide residue on soil at 14 DAA and promoted control levels up to 76.7%, higher doses may provide greater residues and control results closer to 90 or 100%. As previously stated, several researchers have conducted similar studies for different insects and products (Doskocil et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Caballero et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Wu et al. 2015) and new experiments should consider dose-response insecticide effects for \u003cem\u003eS. levis\u003c/em\u003e control. However, a cost-effectiveness analysis of higher insecticide rates should also be conducted to evaluate the economic viability of the operation. Although increasing insecticide application rate increases the application cost, potential yield increment through \u003cem\u003eS. levis\u003c/em\u003e control may reveal to be economically valid. Evaluating the cost-effectiveness of different granular insecticides for pink stem borer (\u003cem\u003eSesamia inferens\u003c/em\u003e Walker) control, authors have reported the economic viability of two applications of solid thiamethoxam (WG) in corn (\u003cem\u003eZea mays\u003c/em\u003e L.) (Sidar et al. \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Moreover, if precision agriculture tools for insect symptomology mapping is proper used, such as satellite multispectral/hyperspectral imagery and unmanned aerial vehicles (UAVs) photogrammetry, site-specific maps for insecticide applications can be used for spot spraying. By only spraying where \u003cem\u003eS. levis\u003c/em\u003e symptoms are detected, the total amount of insecticide to be applied can be drastically reduced in comparison with conventional broadcast/band applications and, therefore, could possibly justify insecticide dose increment. In addition, improved pest control as a result of greater insecticide doses may require less applications and may reduce operational costs in despite of pesticide inputs.\u003c/p\u003e \u003cp\u003eThe higher insecticide rate results also indicate a great potential for solid applications on \u003cem\u003eS. levis\u003c/em\u003e control. As a number of researchers have reported low field efficacies with current insecticides liquid applied for \u003cem\u003eS. levis\u003c/em\u003e control (Dinardo-Miranda et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Tavares \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Alencar \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), current results are an indication that insecticides solid applied can improve pest control, especially if proper granular formulation is adopted (Roy et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Ward \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Allsopp \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In addition to new studies including more insecticides and different active ingredient concentrations, sequential insecticide applications and other integrated pest management (IPM) alternatives should also be tested for \u003cem\u003eS. levis\u003c/em\u003e control potential. Examples of IPM actions should include desiccation and destruction of volunteer cane, bare fallow, crop rotation, seed cane billets of high phytosanitary quality, variety selection, insect baiting, biological control and insecticide\u0026rsquo;s mode of action rotation.\u003c/p\u003e \u003cp\u003eSimilar to Experiment 1 results, a great number of moribund adults was detected during earlier insect evaluations (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e) for both treatments. The first evaluation (4 DAIE), especially, had a high number of \u003cem\u003eS. levis\u003c/em\u003e adults with symptoms of slow, uncoordinated and uncommon movement (Online Resource 2). By the last evaluation, most insects initially showing poisoning symptoms were diagnosed dead (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e"},{"header":"5. Conclusions","content":"\u003cp\u003eThe proposed bioassay methodology simulating \u003cem\u003eS. levis\u003c/em\u003e adult control though insecticide exposure after ratoon sugarcane treatments has proven to be effective for \u003cem\u003eS. levis\u003c/em\u003e adult control evaluation. Based on the results, low \u003cem\u003eS. levis\u003c/em\u003e adult control (\u0026lt;\u0026thinsp;53%) was achieved with both liquid and solid application of insecticides while solid applications prolonged the residual activity in comparison with liquid ones. Solid and liquid application of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam promoted maximum pest control when \u003cem\u003eS. levis\u003c/em\u003e adults were exposed to insecticide residues after seven days from the application. Doubling lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam dose resulted in higher soil residue and greater \u003cem\u003eS. levis\u003c/em\u003e adult control (76.7%) in comparison with the recommended labelled dose (58.8%). The application of solid lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam demonstrated great potential for \u003cem\u003eS. levis\u003c/em\u003e adult control in sugarcane but the development of proper granular formulations including higher active ingredient concentration formulations should optimize insecticide performance for \u003cem\u003eS. levis\u003c/em\u003e control.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eP.H.U.F. performed the study, designed and validated the experiment, analyzed the data, wrote the manuscript, reviewed and edited the manuscript. M.C.F. supervised the study, reviewed and edited the manuscript. E.V. conducted insecticide residue analysis.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was financed in part by the Coordena\u0026ccedil;\u0026atilde;o de Aperfei\u0026ccedil;oamento de Pessoal de N\u0026iacute;vel Superior \u0026ndash; Brasil (CAPES) \u0026ndash; Finance Code 001.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAdditional data information is available from the corresponding author, P.H.U.F., upon reasonable request such as datasets generated and/or analyzed during the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u0026nbsp;\u003c/strong\u003eThe authors declare no competing interests.\u003c/p\u003e "},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAlencar MAV (2016) \u003cem\u003eSphenophorus levis\u003c/em\u003e Vaurie, 1978 (Coleoptera: Curculionidae): caracteriza\u0026ccedil;\u0026atilde;o macrosc\u0026oacute;pica e determina\u0026ccedil;\u0026atilde;o de inseticida e \u0026eacute;poca de aplica\u0026ccedil;\u0026atilde;o para controle. PhD Thesis in Agricultural Entomology, Universidade Estadual Paulista, Jaboticabal, SP. p. 68.\u003c/li\u003e\n \u003cli\u003eAllsopp PG (2020) IPM for Whitegrubs in Australian Sugarcane: From a Continuing Success to Regressing to the Past. Sugar Tech 23:225-238. doi:10.1007/s12355-020-00904-0\u003c/li\u003e\n \u003cli\u003eAnastassiades M, Lehotay SJ, tajnbaher D, Schenck FJ (2003) Fast and easy multiresidue method employing acetonitrile extraction/partitioning and \u0026ldquo;dispersive solid-phase extraction\u0026rdquo; for the determination of pesticide residues in produce. Journal of AOAC International, 86: 412\u0026ndash;431. PMID:12723926\u003c/li\u003e\n \u003cli\u003eAnonymous (2022) Merit\u003csup\u003e\u0026reg;\u003c/sup\u003e 0.5 G insecticide product label. Publication No. 80867190C 161025 AV1. Research Triangle, NC: Bayer Environmental Science.\u003c/li\u003e\n \u003cli\u003eBuhler WG, Gibb TJ (1993) Efficacy of Insecticides on Black Cutworm in Bentgrass, 1992. Insecticide and Acaricide Tests 18: 305-306.\u003c/li\u003e\n \u003cli\u003eCaballero R, Schuster DJ, Smith HA, Mangandi J, Portillo HE (2015) A systemic bioassay to determine susceptibility of the pepper weevil, \u003cem\u003eAnthonomus eugenii\u003c/em\u003e Cano (Coleoptera: Curculionidae) to cyantraniliprole and thiamethoxam. Crop Prot. 72:16-21. doi:doi.org/10.1016/j.cropro.2014.11.002.\u003c/li\u003e\n \u003cli\u003eCasteliani A, Martins LF, Cardoso, JFM, Silva MSO, Silva RSA, Chacon-Orozco JG, Casteliani AGB, Půža V, Harakava R, Leite LG (2020) Behavioral aspects of Sphenophorus levis (Coleoptera: Curculionidae), damage to sugarcane and its natural infection by \u003cem\u003eSteinernema carpocapsae\u003c/em\u003e (Nematoda: Rhabditidae). Crop Prot. 137: 105262. doi:doi.org/10.1016/j.cropro.2020.105262.\u003c/li\u003e\n \u003cli\u003eDavis RF, Wauchope RD, Johnson AW, Burgoa B, Pepperman AB (1996) Release of Fenamiphos, Atrazine, and Alachlor into Flowing Water from Granules and Spray Deposits of Conventional and Controlled-Release Formulations. J Agric Food. Chem. 44:2900\u0026ndash;2907. Doi:10.1021/jf950131x\u003c/li\u003e\n \u003cli\u003eDegaspari N, Botelho NPS, Almeida LC, Castilho HJ (1987) Biologia de Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae) em dieta artificial e no campo. Pesquisa Agropecu\u0026aacute;ria Brasileira 22: 556-558.\u003c/li\u003e\n \u003cli\u003eDinardo-Miranda LL, Fracasso JV, Cabral SB, Val\u0026eacute;rio W, Gon\u0026ccedil;alves RD, Beltrame J\u0026Aacute; (2006) Efici\u0026ecirc;ncia de inseticidas aplicados em soqueiras de cana-de-a\u0026ccedil;\u0026uacute;car no controle de Sphenophorus levis. STAB. A\u0026ccedil;\u0026uacute;car, \u0026Aacute;lcool e subprodutos, 24: 34-37.\u003c/li\u003e\n \u003cli\u003eDinardo-Miranda LL, Fracasso JV (2013) Sugarcane straw and the populations of pests and nematoids. Scientia Agricola 70: 305-310\u003c/li\u003e\n \u003cli\u003eDoskocil JP, Sorenson CE, Royalty RN, Brandenburg RL (2012) Evaluation of Insecticides for Lethal Dose, Lethal Concentration, and Field Activity on Hunting Billbug in Warm-Season Turfgrass. Appl Turfgrass Sci. 9:1\u0026ndash;9. doi:10.1094/ATS-2012-0227-01-RV \u003c/li\u003e\n \u003cli\u003eEmbrapa (2011) Normas para avalia\u0026ccedil;\u0026atilde;o e para indica\u0026ccedil;\u0026atilde;o de inseticidas. In: V Reuni\u0026atilde;o da Comiss\u0026atilde;o Brasileira de Pesquisa de Trigo e Triticale. Regimento, Dourados: Embrapa Agropecu\u0026aacute;ria Oeste: ISBN 978-85-7540-028-9.\u003c/li\u003e\n \u003cli\u003eFern\u0026aacute;ndez-P\u0026eacute;rez M (2007) Controlled release systems to prevent the agro-environmental pollution derived from pesticide use. J Environ Sci Health B 42(7):857\u0026ndash;862. doi:10.1080/03601230701555138\u003c/li\u003e\n \u003cli\u003eFerreira PHU, Ferreira MDC (2023) \u003cem\u003eSphenophorus levis\u003c/em\u003e Behavior Studies: Evaluating Insect Attractiveness or Repellency to One Insecticide Treatment and Assessing Nocturnal Insect Activity and Location Pattern. Insects,\u003cstrong\u003e \u003c/strong\u003e14: 205. doi: 10.3390/insects14020205. PMID: 36835774; PMCID: PMC9962633.\u003c/li\u003e\n \u003cli\u003eGoulson D (2013) An overview of the environmental risks posed by neonicotinoid insecticides. J Appl Ecol. 50:977\u0026ndash;987. doi:10.1111/ 1365-2664.12111\u003c/li\u003e\n \u003cli\u003eHSE, Health and Safety Executive (2020) Efficacy Assessments: UK Product Labelling and National Issues. V. 1.0. July, 2020. https://www.hse.gov.uk/pesticides/pesticides-registration/efficacy-guides/index.htm \u003c/li\u003e\n \u003cli\u003eKimoto N, Takahashi A, Inubushi K (2007) Design and release profile of timed-release coated granules of systemic insecticide. Journal of Pesticide Science 32: 402-406.\u003c/li\u003e\n \u003cli\u003eLenth R (2019) Emmeans: Estimated Marginal Means, aka Least-Squares Means. R package v. 1.3.5.1. \u003c/li\u003e\n \u003cli\u003eLewis KA, Tzilivakis J, Warner D, Green A (2016) An international database for pesticide risk assessments and management. Hum Ecol Risk Assess. 22:1050-1064. doi:10.1080/10807039.2015.1133242\u003c/li\u003e\n \u003cli\u003eMaccuaig RD (1980) Synthetic Pyrethroid Insecticides: Some Studies with Locusts. Trop Pest Manag. 26:349\u0026ndash;354. doi:10.1080/09670878009414915 \u003c/li\u003e\n \u003cli\u003eMartinou AF, Seraphides N, Stavrinides MC (2014) Lethal and behavioral effects of pesticides on the insect predator Macrolophus pygmaeus. Chemosphere 96:167\u0026ndash;173. doi.org/10.1016/j.chemosphere.2013.10.024\u003c/li\u003e\n \u003cli\u003eMoral RA, Hinde J, Dem\u0026eacute;trio CGB (2017) Half-Normal Plots and Overdispersed Models in R: The hnp Package. J Stat Softw. 81:1\u0026ndash;23.\u003c/li\u003e\n \u003cli\u003eM\u0026ouml;rtl M, Kereki O, Darvas B, Kl\u0026aacute;tyik S, Vehovszky A, Gyyri J, Sz\u0026eacute;k\u0026aacute;cs A (2016) Study on Soil Mobility of Two Neonicotinoid Insecticides. J Chem. 2016:1-9. Article ID 4546584. http://dx.doi.org/10.1155/2016/4546584\u003c/li\u003e\n \u003cli\u003eNishimura K, Ohoka M, Fujita T (1987) Quantitative structure-activity studies of pyrethroids: 10. Physicochemical substituent effects of substituted benzyl pyrethrates on symptomatic and neurophysiological activities. Pestic Biochem Phys. 28:257\u0026ndash;270. doi:10.1016/0048-3575(87)90024-1\u003c/li\u003e\n \u003cli\u003eOudou HC, Hansen HCB (2002) Sorption of lambda-cyhalothrin, cypermethrin, deltamethrin and fenvalerate to quartz, corundum, kaolinite and montmorillonite. Chemosphere 49:1285\u0026ndash;1294. doi:10.1016/s0045-6535(02)00507-6 \u003c/li\u003e\n \u003cli\u003ePandey AK, Kumar M (2020) Species profiling of white grub beetles and evaluation of pre and post sown application of insecticides against white grub infesting soybean. International Journal of Agricultural and Biosystems Engineering 14: 10-14. doi.org/10.6084/m9.figshare.12488975\u003c/li\u003e\n \u003cli\u003eP\u0026eacute;rez KG (2008) Efici\u0026ecirc;ncia de iscas t\u0026oacute;xicas no controle de adultos de \u003cem\u003eSphenophorus levis\u003c/em\u003e Vaurie (Coleoptera: Curculinidae) em cana-de-a\u0026ccedil;\u0026uacute;car (\u003cem\u003eSaccharum officinarum\u003c/em\u003e L.). MSc Thesis in Entomology. Universidade de S\u0026atilde;o Paulo, Piracicaba, SP. \u003c/li\u003e\n \u003cli\u003ePrecetti AACM, Arrigoni EB (1990) Aspectos bioecol\u0026oacute;gicos e controle do besouro Sphenophorus levis Vaurie, 1978 (Coleoptera, Curculionidae) em cana-de-a\u0026ccedil;\u0026uacute;car. Boletim T\u0026eacute;cnico Copersucar Edi\u0026ccedil;\u0026atilde;o Especial: 1-15.\u003c/li\u003e\n \u003cli\u003eRaij BV, Andrade JC, Cantarella H, Quaggio JA (2001) An\u0026aacute;lise Qu\u0026iacute;mica para Avalia\u0026ccedil;\u0026atilde;o da Fertilidade de Solos Tropicais. Campinas: Instituto Agron\u0026ocirc;mico; p. 285.\u003c/li\u003e\n \u003cli\u003eRoy A, Singh SK, Bajpai J, Bajpai AK (2014) Controlled pesticide release from biodegradable polymers. Cent Eur J Chem. 12:453-469. doi:10.2478/s11532-013-0405-2\u003c/li\u003e\n \u003cli\u003eRStudio Team (2021) RStudio: Integrated development for R. v. 1.4.1717. RStudio, Inc., Boston, MA. http://www.rstudio.com/.\u003c/li\u003e\n \u003cli\u003eSchneider-Orelli, O (1947). Entomologisches Praktikum. Sauerlander, Aarau, Switzerland.\u003c/li\u003e\n \u003cli\u003eSidar YK, Deole S, Gajbhiye RK, Nirmal A (2017) To evaluate the bioefficacy of granular insecticide molecules against pink stem borer. J Entomol Zool Stud. 5:1114-1120.\u003c/li\u003e\n \u003cli\u003eTavares FM (2006) Avalia\u0026ccedil;\u0026atilde;o de nemat\u0026oacute;ides entomopatog\u0026ecirc;nicos contra o bicudo da cana-de a\u0026ccedil;\u0026uacute;car Sphenophorus levis Vaurie, 1978, e efeito da associa\u0026ccedil;\u0026atilde;o desses agentes com inseticidas qu\u0026iacute;micos. MSc Thesis in Agronomy, Universidade Estadual Paulista, Botucatu, SP. p. 61.\u003c/li\u003e\n \u003cli\u003eTomlin CDS (1997) A World Compendium: The Pesticide Manual. 11th ed. Farnham, Surrey, UK: British Crop Protection Council; pp 300-302.\u003c/li\u003e\n \u003cli\u003eTooming E, Merivee E, Must A, Merivee M-I, Sibul I, Nurme K, Williams IH (2017) Behavioural effects of the neonicotinoid insecticide thiamethoxam on the predatory insect Platynus assimilis. Ecotoxicology 26:902-913. doi:10.1007/s10646-017-1820-5 \u003c/li\u003e\n \u003cli\u003eWard A (2016) Development of controlled release formulations of imidacloprid for canegrub control: final report 2014/006. Indooroopilly, QLD, Australia: Sugar Research Australia Limited. http://hdl.handle.net/11079/17024\u003c/li\u003e\n \u003cli\u003eWu J, Smith MT (2015) Lethal Effects of Lambda-Cyhalothrin and its Commercial Formulation on Asian Longhorned Beetle (Coleoptera: Cerambycidae): Implications for Population Suppression, Tree Protection, Eradication, and Containment. J Econ Entomol. 108:150\u0026ndash;156. doi.org/10.1093/jee/tou052\u003c/li\u003e\n \u003cli\u003eYao F-L, Zheng Y, Zhao J-W, Desneux N, He Y-X, Weng Q-Y (2015) Lethal and sublethal effects of thiamethoxam on the whitefly predator \u003cem\u003eSerangium japonicum\u003c/em\u003e (Coleoptera: Coccinellidae) through different exposure routes. Chemosphere 128:49\u0026ndash;55. doi:10.1016/j.chemosphere.2015.01.010\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"neotropical-entomology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nent","sideBox":"Learn more about [Neotropical Entomology](https://www.springer.com/journal/13744)","snPcode":"13744","submissionUrl":"https://www.editorialmanager.com/nent/default2.aspx","title":"Neotropical Entomology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Billbug, sugarcane weevil, granular, residue, mortality","lastPublishedDoi":"10.21203/rs.3.rs-4018984/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4018984/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe sugarcane weevil (\u003cem\u003eSphenophorus levis\u003c/em\u003e Vaurie, 1978) is currently considered the most important sugarcane pest in Brazil causing significant yield losses. Application methods of insecticides for \u003cem\u003eS. levis\u003c/em\u003e control have not been effective mostly due to the insect\u0026rsquo;s habitat behavior bellow soil surface suppressing the correct placement of the insecticide active ingredient on target. Two experiments were conducted using a novel bioassay methodology that simulates sugarcane field conditions to effectively evaluate \u003cem\u003eS. levis\u003c/em\u003e adult mortality and insecticide soil residue under different treatments. One study aimed to assess the efficacy of two liquid and solid applied insecticides while the second aimed to examinate the effect of increasing lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam dose on \u003cem\u003eS. levis\u003c/em\u003e adult control. The novel bioassays simulated liquid and solid insecticide applications on sugarcane and exposed \u003cem\u003eS. levis\u003c/em\u003e adults to residual rhizome and soil after insecticide application. In the first experiment, low \u003cem\u003eS. levis\u003c/em\u003e adult control was detected (\u0026lt;\u0026thinsp;53% mortality) across all treatments where both solid and liquid applications of lambda-cyhalothrin\u0026thinsp;+\u0026thinsp;thiamethoxam provided greater efficacy levels than imidacloprid and control treatments, respectively. Solid applications promoted greater insecticide concentrations in soil during longer periods in comparison with liquid insecticide applications, providing maximum insect control levels at 7 days after application. In the second experiment, solid applications at higher insecticide dose significantly improved \u003cem\u003eS. levis\u003c/em\u003e adult control (76.7% mortality) in comparison with results of recommended label rate for adult control (58.8% mortality).\u003c/p\u003e","manuscriptTitle":"Improving Sphenophorus levis Adult Mortality with Solid Insecticide Applications and Increased Insecticide Dose","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-18 18:44:34","doi":"10.21203/rs.3.rs-4018984/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2024-03-15T23:56:36+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-03-14T10:59:16+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Neotropical Entomology","date":"2024-03-13T15:19:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-03-08T05:12:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"Neotropical Entomology","date":"2024-03-06T18:33:25+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"neotropical-entomology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nent","sideBox":"Learn more about [Neotropical Entomology](https://www.springer.com/journal/13744)","snPcode":"13744","submissionUrl":"https://www.editorialmanager.com/nent/default2.aspx","title":"Neotropical Entomology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"97078984-5e28-41ae-a642-98e73bcc1de2","owner":[],"postedDate":"March 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-08-27T11:55:11+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-18 18:44:34","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4018984","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4018984","identity":"rs-4018984","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}