Potosia opaca Fabricius 1787 (Coleoptera: Scarabaeidae, Cetoniinae): A new pest on date palm (Phoenix dactylifera l.) from Algerian Oases

Potosia opaca Fabricius 1787 (Coleoptera: Scarabaeidae, Cetoniinae): A new pest on date palm (Phoenix dactylifera l.) from Algerian Oases | 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 Short Report Potosia opaca Fabricius 1787 (Coleoptera: Scarabaeidae, Cetoniinae): A new pest on date palm (Phoenix dactylifera l.) from Algerian Oases Mohamed Seghir Mehaoua, Hanane Bedjaoui, Fateh Mimeche, Adlen Matallah, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5550147/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract In Algeria, date palm cultivation is the most important speculation in the South-East of the country. Since 2012, the Ziban oases have been attacked by a new pest detected on palm trees of the Deglet Nour variety. The xylophagous larvae of this insect destroy the fibrillium commonly called “Lif” in the axils of the palms. This damage is responsible for the phenomenon of palms subsidence observed in palm groves. Based on sampling of L2 and L3 larvae, a mass rearing was conducted to characterize and identify this pest after adult’s emergence. The results of this study allowed the identification of a new species of beetle dependent on the date palm Potosia (Protaetia) opaca Fabricius, 1787 belonging to the Scarabaeidae family and the Cetoniinae subfamily. The morphometric measurements carried out on the different stages of development allowed the characterization of the second and third larval stages, the nymph, the cocoon and the adult of P. opaca. More in-depth studies are needed on the bioecology and the extent of the damage of this pest in order to establish an adequate control program. Figures Figure 1 Key Message Many pests have spread on palm trees due to climate change and non-compliance with agricultural and commercial practices. The number of palm pests in Algeria has increased significantly, most of which belong to the Coleoptera order. The larvae of Potosia opaca attack and destroy the fibrillium of the palms. Introduction The date palm ( Phoenix dactylifera L.) is an essential component of the oasis ecosystem, with its outstanding adaptation to climatic conditions. Date palm is a strategic fruit crop in North Africa and the Middle East, as many socio-economic activities depend on it (Bedjaoui and Benbouza 2018). The particular nature of the date palm and its climatic requirements, which are essential for its growth, make the palm grove environment an extremely special biotope, unfavorable to the development of insects in general. As a result, most date palm pests are monophagous (Viladerbo 1973). In recent years, the number of date palm pests worldwide and in Algeria has been steadily increasing. Some of them have become more prevalent on date palms, encouraged by climate change and non-compliance with cultivation practices and trade (INPV 2016). Since most of these pests belong to the Coleoptera order, namely, Oryctes agamemnon Illiger, 1798 (Bedford et al. 2015), Oxythyrea funesta Poda, 1761, O. pantherina Gory and Percheron, 1833 and Cetonia cuprea Fabricius, 1775 (INPV 2016), Apate monachus Fabricius, 1775, (Munier 1973; Dakhia et al . 2013) and the red weevil Rhynchophorus ferrugeneus Olivier, 1790 (Dembilio and Jaques 2015), not present in Algeria, but subject to intense surveillance to prevent its introduction from the Mediterranean basin countries all affected (INPV 2016). Observing palm subsidence phenomena in one of the Ziban palm groves prompted us to undertake this study. We aim to report and identify a new date palm pest responsible for palm subsidence. Materials and Methods We conducted our work in a date palm grove severely damaged by the palm's subsidence. The grove is located in the commune of Oumeche, 17 km south of the capital of the wilaya of Biskra, and is known for its date palm cultivation. Larval sampling was carried out between October 2016 and May 2017. A set of 40 palms was selected for larvae collection. At the study site, all sampled palms belong to the Deglet Nour variety. Each palm was prospected on three parts: the middle crown, the lower crown, and the upper part of the trunk. Using a ladder and entomological forceps, all larvae behind the petioles (cornaf) were collected. To facilitate prospecting, the extremities of the cornaf were removed from the upper part of the trunk with pruning secateurs. The larvae collected were then placed in perforated plastic boxes, with the date of collection and the name of the site indicated. All samples were put in an electric cooler to keep the larvae in good condition during transport to the laboratory. Larvae were reared at a temperature of 25 °C (Hurpin 1962) in the rearing chamber of the Biskra Regional Plant Protection Station laboratory. This operation aimed to produce adults, allowing us to assign the larvae to the appropriate imago and identify the morphospecies. Rearing was carried out individually in plastic boxes measuring 37.5 mm x 6.5 mm, with a lid perforated by a five-mm-diameter hole. The larvae were reared in a medium consisting of a mixture of chopped and ground palm fiber (Lif). The debris was gathered from infested palms in the study area. Each box was filled to 2/3 of its volume and handled carefully with a brush. Morphometric measurements were performed on 20 individuals of each developmental stage of the pest from mass rearing. The morphological criteria measured were larval weight using a precision balance and larval length and width using an electronic caliper. The length and width of the cephalic capsule were measured using a binocular magnifier with an integrated camera (Motic) equipped with Motic Images Plus measurement software. We used the identification keys of Baraud (1992) and Tauzin (2007) to identify the imagos after they emerged. Results Damage observed on date Palms at the study site (Fig. 1a) took the form of holes and galleries in the Lif, the presence of large quantities of larval excrement behind the cornaf, and the absence of fiber (Lif) in the trunk, resulting in the brittleness of palms in the lower and middle crowns (Fig. 1b, 1c), with the massive presence of P. opaca larvae (Fig. 1). Our results showed that all the larvae collected on the palms were in the L2 and L3 stages. Furthermore, by closely observing the rearing of the collected larvae at the study site, we were able to track the cetoine's developmental stages from the L2 larval stage to the L3 stage, followed by the formation of a shell from palm Lif substrate and excrement (Fig. 1d), during which the larva transitions into a pre-pupa, a pupa, and finally an adult. The average size of the emerging adult varies from 16.63 mm to 20.89 mm. The body is stocky, quadrangular with rounded sides, and varies in color from dull black to greenish-black. The elytra are indented on the side. The ventral side is shiny black, very glossy, as if lacquered, with the presence of pilosity. The metasternal plate is very wide, smooth, and flat, with yellow hair on the inside of the hind tibiae; the mesosternal process is large, smooth, and glabrous. The rearing of P. opaca showed the following results (Table 1): The average weight of L2 stage larvae was 373.35±39.55mg, the width of the cephalic capsule (Fig. 1e) was 2415.46 ± 43.92µm, and its length was 1800.71 ± 63.43µm. For the L3 stage (Fig. 1f), the average larval weight is 1700.16 ± 78.09 mg, and the width and length of the cephalic capsule are 4072.37 ± 46.92µm and 3119 ± 256.21µm, respectively. The P. opaca pupa is characterized by an average weight of 547.96 ± 97.24 mg, a width of 9.91 ± 0.36 mm, and a length of 15.71 ± 1.82 mm ((Fig. 1g, 1h). The average cocoon width is 14.36±2.02 mm, with a length of 19.82±1.86 mm. In P. opaca , the average adult length is 18.11±0.7mm, while the average width is 10.48±0.22mm (Fig. 1j, 1k). Table 1. Morphometric characterization of the different stages of P. opaca (n=80) Development stage Parameters average ± SD Minimum Maximum Larval stage L2 Larva length (mm) 19.04±1.35 11.68 23.07 Larva width (mm) 5.66±0.27 4.95 6.91 Weight (mg) 373.35±39.55 174.7 517.7 Cephalic capsule length (µm) 1800.71±63.43 1576.8 2160.7 Cephalic capsule width (µm) 2415.46±43.92 2255.2 2596.4 Larval stage L3 Larva length (mm) 31.3±0.85 24.25 37.58 Larva width (mm) 9.15±0.24 6.75 10.56 Weight (mg) 1700.2±78.09 1184.4 2314.5 Cephalic capsule length (µm) 3119.01±57.29 2262.5 3461.8 Cephalic capsule width (µm) 4072.37±46.92 3704.8 4392.8 Nymphs Length (mm) 15.71±1.05 14.24 17.75 Width (mm) 9.917±0.36 9.23 10.46 Weight (mg) 547.967±97.24 442.4 742.2 Cocoons Length (mm) 19.82±0.70 17.44 22.53 Width (mm) 14.36±0.78 12.17 17.78 Adults Length (mm) 18.12±0.7 16.63 20.89 Width (mm) 10.48±0.22 10.03 11.5 Discussion The problem of palm subsidence in the Biskra region was reported by the National Institute of Plant Protection (INPV) in 2012. The results of the survey conducted by INPV services attributed the caused damage to three species of cetonea captured on affected palms: " Oxytherea funesta, Oxythere apantherena , and Cetonea faveata " (INPV 2016). The latter has never been noted by other authors as a date palm pest. Moreover, they are not considered xylophagous species but rather saproxylophagous species, contrary to the xylophagous species concerned by our study, and which is the one responsible for the damage observed in the field. In Spain, however, Mico and Galante (2003) reported three other species of date palm beetles: Potosia opaca, Potosia cuprea , and Netocia oblenga . To clarify any ambiguity regarding the phenomenon of palm subsidence in the Biskra region, we proceeded to diagnose the damage observed in the palm groves surveyed. Our results showed that another xylophagous species is responsible for this damage. Lack of knowledge of this species, especially of its feeding and sexual behavior, explains the difficulties encountered during the mass rearing of this pest. However, the emergence of adults enabled us to identify Potosia opaca as the species responsible for the damage observed on date palms. The description of the adults is similar to that of Paulian (1941), Baraud (1992), and Tauzin (2007). The pest Potosia opaca Fabricus, 1787, belongs to the order Coleoptera, family Scarabaeidae, and subfamily Cetoniinae (Dutto 2006; Bouchaour-Djabeur 2013). In Algeria, P. opaca has never been reported on date palms but is present on cork oaks in the suberaie of El-Kala National Park (Adjami 2009). Paulian (1959), Baraud (1985), and Baraud (1992) have also indicated that in Algeria, P. opaca is mainly distributed in the coastal zone. Its southern limit seems to be located on the High plateaux in the west and center and against the Aurès massif in the southeast. On the other hand, P. opaca was reported in Spain on date palms in Elche, San Vicente, and Alicante (Alicante, Spain) in 1997, 1999, and 2000, respectively (Mico and Galante 2003). Similarly, in the Navarre region of Spain, San Martin et al. (2001) reported that P. opaca is abundant in forest areas with Quercus faginea , Quercus ilex , and Quercus humilis . They also found it in the Moroccan High Atlas below the Tizi N'Test pass (Tauzin, 2007). P. opaca damage observed on date palms was localized on Deglet Nour palms at the level of the lower crown, the middle crown, and the trunk (cornaf cavity). As an indicator of their presence, excrement can be visibly observed in the palm axils. The large mass of isolated larvae has formed galleries in the fibrillium (Lif) and cornaf, weakening the palms and causing them to subside. The P. opaca species generally have an annual development cycle from the egg to the imago stage, with xylophagous larvae (Tauzin 2007). In Tunisia, Ben Jamâa et al.(2017) reported that P. opaca develops a single generation per year on Phoenix canariensis . The absence of both the egg and the L1 larval stages at the sampling time is probably due to the difficulty of collecting them. Mico and Galante (2003) mentioned the presence of only two larval stages, L2 and L3, of the same species on date palms in the Elche, San Vicente, and Alicante regions of Spain. These authors' observations confirm the absence of the egg and L1 developmental stages in our sample. However, Paulian (1941) notes that beetles go through three larval stages, with the first stage always significantly shorter than the next two. Despite the wide distribution of beetles worldwide, little work has been done to describe larval stages. The two main works in this field are those by Klausnitzer and Krell (1997) and Mico and Galante (2003), which describe only the L3 larval stage. The results of morphometric measurements carried out on P. opaca L3 larvae are close to the larval description made by Mico and Galant (2003) on nine third-stage P. opaca larvae reared from eggs laid by adults collected in El Garbinet, Alicante (Spain), which showed that the maximum width of the cephalic capsule is 4.6 to 4.9 mm. The results of the measured lengths of P. opaca adults from our mass rearing corroborate with those recorded by Paulian (1941) and Baraud (1992), with lengths ranging from 15 to 23 mm and 16 to 27mm, respectively. The records reported here indicate that the P. opaca is potentially important pests in Algeria. Since P. opaca has not been noted previously as a pest of date palm, further research on this species and its effects on this economically important crop is especially warranted. Declarations Author contributions Mohamed Seghir Mehaoua, Adlen Matallah, and Nabil Boubakeur conceived and designed the experiment. Mohamed Seghir Mehaoua, Hanane Bedjaoui and Fateh Mimeche acquired funding. Mohamed Seghir Mehaoua, Adlen Matallah, Nabil Boubakeur, and Ayoub Hadjeb conducted the experiment. Mohamed Seghir Mehaoua and Fateh Mimeche curated the data. Mohamed Seghir Mehaoua, Fateh Mimeche and Hanane Bedjaoui analyzed the data and wrote the frst draft of the manuscript. All authors discussed the results and edited the manuscript. Funding The research leading to these results received funding from Project Prfu: D04N01UN070120220003, Ministry of Higher Education and Scientific Research Algeria Declarations Conflict of interest The authors have no competing interests to declare that are relevant to the content of this article. Ethical approval All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. This article does not contain any studies with human participants performed by any of the authors References Adjami Y (2009) Etudes des facteurs de dépérissement dans la subéraie d'El-Kala (Nord-Est Algérien) : cas de la subéraie d'El- Mellah. Dissertation, University of Annaba Baraud J (1985) Scarabaeoidea beetles. Fauna of North Africa, from Morocco to Sinai . Lechevalier, Paris Baraud J (1992) Beetles Scarabaeoidea of Europe . Fauna of France and Neighboring Regions. Fédération française des Sociétés de Sciences Naturelles de Lyon, Lyon Bedford GO, Al-deeb MA, khalaf MZ, Mohammadpour K, Soltani R (2015) Dynastid beetle pests. In: Wakil W et al. (ed) Sustainable Pest Management in Date Palm: Current Status and Emerging Challenges, Sustainability in Plant and Crop Protectionm, Springer, Switzerland, pp 73-108. Bedjaoui H, Benbouza, H (2020) Assessment of phenotypic diversity of local Algerian date palm ( Phoenix dactylifera L.) cultivars. J Saudi Soc Agric Sci 19(1): 65-75. https://doi.org/10.1016/j.jssas.2018.06.002. Ben Jamâa M L, Boudhina S, Dhahri S, Hdidi S (2017) Potosia opaca , an insect newly found on Canary palm ( Phoenix canariensis ) in Tunisia. Plant Protection 12: 83-90. Bouchaour-Djabeur S (2013) Les insectes ravageurs du chêne liège au Nord-Ouest Algérien. International Geo Eco Trop 36: 175-184. Dembilio Ó, Jaques JA (2015) Biology and management of red palm weevil. In: Wakil W et al. (ed) Sustainable Pest Management in Date Palm: Current Status and Emerging Challenges, Sustainability in Plant and Crop Protectionm, Springer, Switzerland, pp 13-36. Dutto M (2006) Osservazioni bionomiche e geonemiche su Potosia opaca (Fabricius, 1787) (Coleoptera, Cetoniidae). Atti Mus Civ Stor Nat Triest 53: 215-222. Hurpin B (1962). Super-famille des Scarabaeidae. In: Balachowsky AS (ed) Entomologie appliquée à l’agriculture. Tome I- Coléoptére. Masson, Paris, pp 24-204. INPV (2016) The three pest beetles. Diseases of palm trees. Algiers: A.G.R.I.V.E.T Consulting. Klausnitzer BD, Krell FT (1997) Überfamilie: Scarabaeoidea. Die Larven der Käfer Mitteleuropas 3: 11-89. Mico E, Galante E (2003) Larval morphology and biology of four Netocia and Potosia species (Coleoptera: Scarabaeoidea: Cetoniidae: Cetoniinae). Eur J Entomol 100(1): 131-142.https://doi.org/10.14411/eje.2003.023 Munier P (1973) The date palm . Bontemps, Limoges. Paulian R (1941) Fauna of France. 38. Beetles Scarabellas. Lechevalier, Paris. Paulian R (1959) Beetles Scarabaeids. Fauna of France. Lechevalier, Paris. San Martin A, Recalde J, Agoïz J (2001) Corologie de los Cetonidos de Navarra (Coleoptera : Cetoniidae). Zapateri Rvta Arag Ent 9: 65-74. Tauzin P (2007) Chorologie de Protaetia ( Potosia ) opaca Fabricius 1787 en France (Coleoptera, Cetoniinae, Cetoniini). Cetoniimania 19-48. Viladerbo A (1973). Principaux parasites de la datte et du dattier . In: Munier P (ed) Le Palmier dattier. Maisonneuve et Larousse, Paris, pp 67- 95. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-5550147","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":390825479,"identity":"a5086ecf-60e6-46ed-aaf9-720977bdf4ee","order_by":0,"name":"Mohamed Seghir Mehaoua","email":"","orcid":"","institution":"University of Biskra","correspondingAuthor":false,"prefix":"","firstName":"Mohamed","middleName":"Seghir","lastName":"Mehaoua","suffix":""},{"id":390825480,"identity":"5d02162f-4231-4f70-b603-26d40a7f4c98","order_by":1,"name":"Hanane Bedjaoui","email":"","orcid":"","institution":"University of Biskra","correspondingAuthor":false,"prefix":"","firstName":"Hanane","middleName":"","lastName":"Bedjaoui","suffix":""},{"id":390825481,"identity":"cbc53867-1ea4-4389-b213-812ac24a1934","order_by":2,"name":"Fateh Mimeche","email":"data:image/png;base64,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","orcid":"","institution":"University of M'Sila","correspondingAuthor":true,"prefix":"","firstName":"Fateh","middleName":"","lastName":"Mimeche","suffix":""},{"id":390825482,"identity":"c18aae4c-295b-476a-9bdd-b16bfa91f5b4","order_by":3,"name":"Adlen Matallah","email":"","orcid":"","institution":"EL-Oued","correspondingAuthor":false,"prefix":"","firstName":"Adlen","middleName":"","lastName":"Matallah","suffix":""},{"id":390825483,"identity":"85dbe924-a351-4100-98b2-3abe01f384d7","order_by":4,"name":"Nabil Boubakeur","email":"","orcid":"","institution":"University of Biskra","correspondingAuthor":false,"prefix":"","firstName":"Nabil","middleName":"","lastName":"Boubakeur","suffix":""},{"id":390825484,"identity":"0eeb64db-f05e-47a3-99b9-fec9287ff3f1","order_by":5,"name":"Ayoub Hadjeb","email":"","orcid":"","institution":"University of Biskra","correspondingAuthor":false,"prefix":"","firstName":"Ayoub","middleName":"","lastName":"Hadjeb","suffix":""}],"badges":[],"createdAt":"2024-11-29 15:23:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5550147/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5550147/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":71592178,"identity":"00f91ad5-336d-4e07-9683-0863c05a437e","added_by":"auto","created_at":"2024-12-17 03:31:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2651403,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eP. opaca\u003c/em\u003e on date Palms at the study site, (a): damage on lower and middle crowns; (b):\u003cstrong\u003e \u003c/strong\u003eLarval damage on Lif, (c): damage on inner bark of cornaf, (d): the excrement of Larvae on the Deglet Nour cultivar, (e):Head capsule of L2 larva \u003cem\u003eP. opaca\u003c/em\u003e , (f): larva L3 \u003cem\u003eP. opaca\u003c/em\u003e, (g): pupa,( h): Emerging adult, (j): Adult facing dorsal, (k): Adult facing ventral.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5550147/v1/505361c152e0e6dd3aba6731.png"},{"id":71592751,"identity":"0686d8d4-bcd8-4196-a420-c91e3f2bdbcf","added_by":"auto","created_at":"2024-12-17 03:39:02","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2791523,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5550147/v1/9955b328-2ddd-4120-a591-a07b5aaf0f44.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Potosia opaca Fabricius 1787 (Coleoptera: Scarabaeidae, Cetoniinae): A new pest on date palm (Phoenix dactylifera l.) from Algerian Oases","fulltext":[{"header":"Key Message","content":"\u003cul\u003e\n \u003cli\u003eMany pests have spread on palm trees due to climate change and non-compliance with agricultural and commercial practices.\u003c/li\u003e\n \u003cli\u003eThe number of palm pests in Algeria has increased significantly, most of which belong to the Coleoptera order.\u003c/li\u003e\n \u003cli\u003eThe larvae of \u003cem\u003ePotosia opaca\u003c/em\u003e attack and destroy the fibrillium of the palms.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Introduction","content":"\u003cp\u003eThe date palm (\u003cem\u003ePhoenix dactylifera\u003c/em\u003e L.) is an essential component of the oasis ecosystem, with its outstanding adaptation to climatic conditions. Date palm is a strategic fruit crop in North Africa and the Middle East, as many socio-economic activities depend on it (Bedjaoui and Benbouza 2018). The particular nature of the date palm and its climatic requirements, which are essential for its growth, make the palm grove environment an extremely special biotope, unfavorable to the development of insects in general. As a result, most date palm pests are monophagous (Viladerbo 1973). In recent years, the number of date palm pests worldwide and in Algeria has been steadily increasing. Some of them have become more prevalent on date palms, encouraged by climate change and non-compliance with cultivation practices and trade (INPV 2016). Since most of these pests belong to the Coleoptera order, namely, \u003cem\u003eOryctes agamemnon\u003c/em\u003e Illiger, 1798 (Bedford et al. 2015), \u003cem\u003eOxythyrea funesta\u003c/em\u003e Poda, 1761, \u003cem\u003eO. pantherina\u003c/em\u003e Gory and Percheron, 1833 and \u003cem\u003eCetonia cuprea\u003c/em\u003e Fabricius, 1775 (INPV 2016), \u003cem\u003eApate monachus\u003c/em\u003e Fabricius, 1775, \u0026nbsp;(Munier 1973; Dakhia et al\u003cem\u003e.\u003c/em\u003e 2013) and the red weevil \u003cem\u003eRhynchophorus ferrugeneus\u003c/em\u003e Olivier, 1790 (Dembilio and Jaques 2015), not present in Algeria, but subject to intense surveillance to prevent its introduction from the Mediterranean basin countries all affected (INPV 2016).\u003c/p\u003e\n\u003cp\u003eObserving palm subsidence phenomena in one of the Ziban palm groves prompted us to undertake this study. We aim to report and identify a new date palm pest responsible for palm subsidence.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eWe conducted our work in a date palm grove severely damaged by the palm\u0026apos;s subsidence. The grove is located in the commune of Oumeche, 17 km south of the capital of the wilaya of Biskra, and is known for its date palm cultivation.\u003c/p\u003e\n\u003cp\u003eLarval sampling was carried out between October 2016 and May 2017. A set of 40 palms was selected for larvae collection. At the study site, all sampled palms belong to the Deglet Nour variety. Each palm was prospected on three parts: the middle crown, the lower crown, and the upper part of the trunk. Using a ladder and entomological forceps, all larvae behind the petioles (cornaf) were collected. To facilitate prospecting, the extremities of the cornaf were removed from the upper part of the trunk with pruning secateurs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe larvae collected were then placed in perforated plastic boxes, with the date of collection and the name of the site indicated. All samples were put in an electric cooler to keep the larvae in good condition during transport to the laboratory. Larvae were reared at a temperature of 25 \u0026deg;C (Hurpin 1962) in the rearing chamber of the Biskra Regional Plant Protection Station laboratory. This operation aimed to produce adults, allowing us to assign the larvae to the appropriate imago and identify the morphospecies.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eRearing was carried out individually in plastic boxes measuring 37.5 mm x 6.5 mm, with a lid perforated by a five-mm-diameter hole. The larvae were reared in a medium consisting of a mixture of chopped and ground palm fiber (Lif). The debris was gathered from infested palms in the study area. Each box was filled to 2/3 of its volume and handled carefully with a brush.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMorphometric measurements were performed on 20 individuals of each developmental stage of the pest from mass rearing. The morphological criteria measured were larval weight using a precision balance and larval length and width using an electronic caliper. The length and width of the cephalic capsule were measured using a binocular magnifier with an integrated camera (Motic) equipped with Motic Images Plus measurement software. We used the identification keys of Baraud (1992) and Tauzin (2007) to identify the imagos after they emerged.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eDamage observed on date Palms at the study site (Fig. 1a) took the form of holes and galleries in the Lif, the presence of large quantities of larval excrement behind the cornaf, and the absence of fiber (Lif) in the trunk, resulting in the brittleness of palms in the lower and middle crowns (Fig. 1b, 1c), with the massive presence of \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003elarvae (Fig. 1).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur results showed that all the larvae collected on the palms were in the L2 and L3 stages. Furthermore, by closely observing the rearing of the collected larvae at the study site, we were able to track the cetoine\u0026apos;s developmental stages from the L2 larval stage to the L3 stage, followed by the formation of a shell from palm Lif substrate and excrement (Fig. 1d), during which the larva transitions into a pre-pupa, a pupa, and finally an adult. The average size of the emerging adult varies from 16.63 mm to 20.89 mm. The body is stocky, quadrangular with rounded sides, and varies in color from dull black to greenish-black. The elytra are indented on the side. The ventral side is shiny black, very glossy, as if lacquered, with the presence of pilosity.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe metasternal plate is very wide, smooth, and flat, with yellow hair on the inside of the hind tibiae; the mesosternal process is large, smooth, and glabrous.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe rearing of \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003eshowed the following results (Table 1): The average weight of L2 stage larvae was 373.35\u0026plusmn;39.55mg, the width of the cephalic capsule (Fig. 1e) was 2415.46 \u0026plusmn; 43.92\u0026micro;m, and its length was 1800.71 \u0026plusmn; 63.43\u0026micro;m. For the L3 stage (Fig. 1f), the average larval weight is 1700.16 \u0026plusmn; 78.09 mg, and the width and length of the cephalic capsule are 4072.37 \u0026plusmn; 46.92\u0026micro;m and 3119 \u0026plusmn; 256.21\u0026micro;m, respectively. The \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003epupa is characterized by an average weight of 547.96 \u0026plusmn; 97.24 mg, a width of 9.91 \u0026plusmn; 0.36 mm, and a length of 15.71 \u0026plusmn; 1.82 mm ((Fig. 1g, 1h). The average cocoon width is 14.36\u0026plusmn;2.02 mm, with a length of 19.82\u0026plusmn;1.86 mm. In \u003cem\u003eP. opaca\u003c/em\u003e, the average adult length is 18.11\u0026plusmn;0.7mm, while the average width is 10.48\u0026plusmn;0.22mm (Fig. 1j, 1k).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u0026nbsp;\u003c/strong\u003eMorphometric characterization of the different stages of \u003cem\u003eP. opaca \u0026nbsp;\u003c/em\u003e(n=80)\u003c/p\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"577\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDevelopment stage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eParameters\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eaverage \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMinimum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMaximum\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"5\"\u003e\n \u003cp\u003eLarval stage L2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLarva length (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e19.04\u0026plusmn;1.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e11.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e23.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLarva width (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e5.66\u0026plusmn;0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e4.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e6.91\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eWeight (mg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e373.35\u0026plusmn;39.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e174.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e517.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCephalic capsule length (\u0026micro;m)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1800.71\u0026plusmn;63.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1576.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2160.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCephalic capsule width (\u0026micro;m)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2415.46\u0026plusmn;43.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2255.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2596.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"5\"\u003e\n \u003cp\u003eLarval stage L3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLarva length (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e31.3\u0026plusmn;0.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e24.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e37.58\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLarva width (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e9.15\u0026plusmn;0.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e6.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e10.56\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eWeight (mg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1700.2\u0026plusmn;78.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1184.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2314.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCephalic capsule length (\u0026micro;m)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e3119.01\u0026plusmn;57.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2262.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e3461.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCephalic capsule width (\u0026micro;m)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e4072.37\u0026plusmn;46.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e3704.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e4392.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\"\u003e\n \u003cp\u003eNymphs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eLength (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e15.71\u0026plusmn;1.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e14.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e17.75\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eWidth (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e9.917\u0026plusmn;0.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e9.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e10.46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eWeight (mg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e547.967\u0026plusmn;97.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e442.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e742.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003eCocoons\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eLength (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e19.82\u0026plusmn;0.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e17.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e22.53\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eWidth (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e14.36\u0026plusmn;0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e12.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e17.78\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003eAdults\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eLength (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e18.12\u0026plusmn;0.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e16.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e20.89\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eWidth (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e10.48\u0026plusmn;0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e10.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e11.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe problem of palm subsidence in the Biskra region was reported by the National Institute of Plant Protection (INPV) in 2012. The results of the survey conducted by INPV services attributed the caused damage to three species of cetonea captured on affected palms: \u0026quot;\u003cem\u003eOxytherea funesta, Oxythere apantherena\u003c/em\u003e, and \u003cem\u003eCetonea faveata\u003c/em\u003e\u0026quot; (INPV 2016). The latter has never been noted by other authors as a date palm pest. Moreover, they are not considered xylophagous species but rather saproxylophagous species, contrary to the xylophagous species concerned by our study, and which is the one responsible for the damage observed in the field. In Spain, however, Mico and Galante (2003) reported three other species of date palm beetles: \u003cem\u003ePotosia opaca, Potosia cuprea\u003c/em\u003e, and \u003cem\u003eNetocia oblenga\u003c/em\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo clarify any ambiguity regarding the phenomenon of palm subsidence in the Biskra region, we proceeded to diagnose the damage observed in the palm groves surveyed. Our results showed that another xylophagous species is responsible for this damage. Lack of knowledge of this species, especially of its feeding and sexual behavior, explains the difficulties encountered during the mass rearing of this pest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHowever, the emergence of adults enabled us to identify \u003cem\u003ePotosia opaca\u003c/em\u003eas the species responsible for the damage observed on date palms. The description of the adults is similar to that of Paulian (1941), Baraud (1992), and Tauzin (2007). The pest \u003cem\u003ePotosia opaca\u0026nbsp;\u003c/em\u003eFabricus, 1787, belongs to the order Coleoptera, family Scarabaeidae, and subfamily Cetoniinae (Dutto 2006; Bouchaour-Djabeur 2013).\u003c/p\u003e\n\u003cp\u003eIn Algeria, \u003cem\u003eP. opaca\u003c/em\u003ehas never been reported on date palms but is present on cork oaks in the suberaie of El-Kala National Park (Adjami 2009). Paulian (1959), Baraud (1985), and Baraud (1992) have also indicated that in Algeria, \u003cem\u003eP. opaca\u003c/em\u003eis mainly distributed in the coastal zone. Its southern limit seems to be located on the High plateaux in the west and center and against the Aur\u0026egrave;s massif in the southeast.\u003c/p\u003e\n\u003cp\u003eOn the other hand, \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003ewas reported in Spain on date palms in Elche, San Vicente, and Alicante (Alicante, Spain) in 1997, 1999, and 2000, respectively (Mico and Galante 2003). Similarly, in the Navarre region of Spain, San Martin et al. (2001) reported that \u003cem\u003eP. opaca\u003c/em\u003eis abundant in forest areas with \u003cem\u003eQuercus faginea\u003c/em\u003e, \u003cem\u003eQuercus ilex\u003c/em\u003e, and \u003cem\u003eQuercus humilis\u003c/em\u003e. They also found it in the Moroccan High Atlas below the Tizi N\u0026apos;Test pass (Tauzin, 2007).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003edamage observed on date palms was localized on Deglet Nour palms at the level of the lower crown, the middle crown, and the trunk (cornaf cavity). As an indicator of their presence, excrement can be visibly observed in the palm axils. The large mass of isolated larvae has formed galleries in the fibrillium (Lif) and cornaf, weakening the palms and causing them to subside.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003especies generally have an annual development cycle from the egg to the imago stage, with xylophagous larvae (Tauzin 2007). In Tunisia, Ben Jam\u0026acirc;a et al.(2017) reported that \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003edevelops a single generation per year on \u003cem\u003ePhoenix canariensis\u003c/em\u003e. The absence of both the egg and the L1 larval stages at the sampling time is probably due to the difficulty of collecting them. Mico and Galante (2003) mentioned the presence of only two larval stages, L2 and L3, of the same species on date palms in the Elche, San Vicente, and Alicante regions of Spain. These authors\u0026apos; observations confirm the absence of the egg and L1 developmental stages in our sample. However, Paulian (1941) notes that beetles go through three larval stages, with the first stage always significantly shorter than the next two.\u003c/p\u003e\n\u003cp\u003eDespite the wide distribution of beetles worldwide, little work has been done to describe larval stages. The two main works in this field are those by Klausnitzer and Krell (1997) and Mico and Galante (2003), which describe only the L3 larval stage.\u003c/p\u003e\n\u003cp\u003eThe results of morphometric measurements carried out on \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003eL3 larvae are close to the larval description made by Mico and Galant (2003) on nine third-stage \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003elarvae reared from eggs laid by adults collected in El Garbinet, Alicante (Spain), which showed that the maximum width of the cephalic capsule is 4.6 to 4.9 mm. The results of the measured lengths of \u003cem\u003eP. opaca\u0026nbsp;\u003c/em\u003eadults from our mass rearing corroborate with those recorded by Paulian (1941) and Baraud (1992), with lengths ranging from 15 to 23 mm and 16 to 27mm, respectively.\u003c/p\u003e\n\u003cp\u003eThe records reported here indicate that the \u003cem\u003eP. opaca\u003c/em\u003e is potentially important pests in Algeria. Since \u003cem\u003eP. opaca\u003c/em\u003e has not been noted previously as a pest of date palm, further research on this species and its effects on this economically important crop is especially warranted.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMohamed Seghir Mehaoua, Adlen Matallah, and Nabil Boubakeur conceived and designed the experiment. Mohamed Seghir Mehaoua, Hanane Bedjaoui and Fateh Mimeche acquired funding. Mohamed Seghir Mehaoua, Adlen Matallah, Nabil Boubakeur, and Ayoub Hadjeb conducted the experiment. Mohamed Seghir Mehaoua and Fateh Mimeche curated the data. Mohamed Seghir Mehaoua, Fateh Mimeche and Hanane Bedjaoui analyzed the data and wrote the frst draft of the manuscript. All authors discussed the results and edited the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe research leading to these results received funding from Project Prfu: \u003cstrong\u003eD04N01UN070120220003,\u0026nbsp;\u003c/strong\u003eMinistry of Higher Education and Scientific Research Algeria\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDeclarations\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The authors have no competing interests to declare that are relevant to the content of this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u0026nbsp; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll applicable international, national, and/or institutional guidelines for the care and use of animals were followed. This article does not contain any studies with human participants performed\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eby any of the authors\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAdjami Y (2009) Etudes des facteurs de d\u0026eacute;p\u0026eacute;rissement dans la sub\u0026eacute;raie d'El-Kala (Nord-Est Alg\u0026eacute;rien) : cas de la sub\u0026eacute;raie d'El- Mellah. Dissertation, University of Annaba\u003c/li\u003e\n\u003cli\u003eBaraud J (1985) Scarabaeoidea beetles. Fauna of North Africa, from Morocco to Sinai\u003cem\u003e.\u003c/em\u003e Lechevalier, Paris\u003c/li\u003e\n\u003cli\u003eBaraud J (1992) Beetles Scarabaeoidea of Europe\u003cem\u003e. \u003c/em\u003eFauna of France and Neighboring Regions. F\u0026eacute;d\u0026eacute;ration fran\u0026ccedil;aise des Soci\u0026eacute;t\u0026eacute;s de Sciences Naturelles de Lyon, Lyon\u003c/li\u003e\n\u003cli\u003eBedford GO, Al-deeb MA, khalaf MZ, Mohammadpour K, Soltani R (2015) Dynastid beetle pests. In: Wakil W et al. (ed) Sustainable Pest Management in Date Palm: Current Status and Emerging Challenges, Sustainability in Plant and Crop Protectionm, Springer, Switzerland, pp 73-108.\u003c/li\u003e\n\u003cli\u003eBedjaoui H, Benbouza, H (2020) Assessment of phenotypic diversity of local Algerian date palm (\u003cem\u003ePhoenix dactylifera\u003c/em\u003e L.) cultivars. J Saudi Soc Agric Sci 19(1): 65-75. https://doi.org/10.1016/j.jssas.2018.06.002.\u003c/li\u003e\n\u003cli\u003eBen Jam\u0026acirc;a M L, Boudhina S, Dhahri S, Hdidi S (2017) \u003cem\u003ePotosia\u003c/em\u003e \u003cem\u003eopaca\u003c/em\u003e, an insect newly found on Canary palm (\u003cem\u003ePhoenix canariensis\u003c/em\u003e) in Tunisia.\u0026nbsp;Plant Protection 12: 83-90.\u003c/li\u003e\n\u003cli\u003eBouchaour-Djabeur S (2013) Les insectes ravageurs du ch\u0026ecirc;ne li\u0026egrave;ge au Nord-Ouest Alg\u0026eacute;rien. International Geo Eco Trop 36: 175-184.\u003c/li\u003e\n\u003cli\u003eDembilio \u0026Oacute;, Jaques JA (2015) Biology and management of red palm weevil. In: Wakil W et al. (ed) Sustainable Pest Management in Date Palm: Current Status and Emerging Challenges, Sustainability in Plant and Crop Protectionm, Springer, Switzerland, pp 13-36.\u003c/li\u003e\n\u003cli\u003eDutto M (2006) Osservazioni bionomiche e geonemiche su \u003cem\u003ePotosia opaca\u003c/em\u003e (Fabricius, 1787) (Coleoptera, Cetoniidae). \u0026nbsp;Atti Mus Civ Stor Nat Triest 53: 215-222.\u003c/li\u003e\n\u003cli\u003eHurpin B (1962). Super-famille des Scarabaeidae. In: Balachowsky AS (ed) Entomologie appliqu\u0026eacute;e \u0026agrave; l\u0026rsquo;agriculture. Tome I- Col\u0026eacute;opt\u0026eacute;re. Masson, Paris, pp 24-204.\u003c/li\u003e\n\u003cli\u003eINPV (2016) The three pest beetles. Diseases of palm trees. Algiers: A.G.R.I.V.E.T Consulting.\u003c/li\u003e\n\u003cli\u003eKlausnitzer BD, Krell FT (1997) \u0026Uuml;berfamilie: Scarabaeoidea. Die Larven der K\u0026auml;fer Mitteleuropas 3: 11-89.\u003c/li\u003e\n\u003cli\u003eMico E, Galante E (2003) Larval morphology and biology of four Netocia and Potosia species (Coleoptera: Scarabaeoidea: Cetoniidae: Cetoniinae).\u0026nbsp;Eur J Entomol 100(1): 131-142.https://doi.org/10.14411/eje.2003.023\u003c/li\u003e\n\u003cli\u003eMunier P (1973) The date palm\u003cem\u003e.\u003c/em\u003e Bontemps, Limoges.\u003c/li\u003e\n\u003cli\u003ePaulian R (1941) Fauna of France. 38. Beetles Scarabellas. \u0026nbsp; Lechevalier, Paris.\u003c/li\u003e\n\u003cli\u003ePaulian R (1959)\u0026nbsp; Beetles Scarabaeids. Fauna of France. Lechevalier, Paris.\u003c/li\u003e\n\u003cli\u003eSan Martin A, Recalde J, Ago\u0026iuml;z J (2001) Corologie de los Cetonidos de Navarra (Coleoptera : Cetoniidae). Zapateri Rvta Arag Ent 9: 65-74.\u003c/li\u003e\n\u003cli\u003eTauzin P (2007) Chorologie de \u003cem\u003eProtaetia\u003c/em\u003e (\u003cem\u003ePotosia\u003c/em\u003e) \u003cem\u003eopaca\u003c/em\u003e Fabricius 1787 en France (Coleoptera, Cetoniinae, Cetoniini). Cetoniimania 19-48.\u003c/li\u003e\n\u003cli\u003eViladerbo A (1973). Principaux parasites de la datte et du dattier\u003cem\u003e. \u003c/em\u003eIn: Munier P (ed) Le Palmier dattier. \u0026nbsp;Maisonneuve et Larousse, Paris, pp 67- 95.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5550147/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5550147/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"In Algeria, date palm cultivation is the most important speculation in the South-East of the country. Since 2012, the Ziban oases have been attacked by a new pest detected on palm trees of the Deglet Nour variety. The xylophagous larvae of this insect destroy the fibrillium commonly called “Lif” in the axils of the palms. This damage is responsible for the phenomenon of palms subsidence observed in palm groves. Based on sampling of L2 and L3 larvae, a mass rearing was conducted to characterize and identify this pest after adult’s emergence. The results of this study allowed the identification of a new species of beetle dependent on the date palm Potosia (Protaetia) opaca Fabricius, 1787 belonging to the Scarabaeidae family and the Cetoniinae subfamily. The morphometric measurements carried out on the different stages of development allowed the characterization of the second and third larval stages, the nymph, the cocoon and the adult of P. opaca. More in-depth studies are needed on the bioecology and the extent of the damage of this pest in order to establish an adequate control program.","manuscriptTitle":"Potosia opaca Fabricius 1787 (Coleoptera: Scarabaeidae, Cetoniinae): A new pest on date palm (Phoenix dactylifera l.) from Algerian Oases","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-17 03:30:56","doi":"10.21203/rs.3.rs-5550147/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"27abe6b5-5a6a-4e4e-9146-b6b63dea3bee","owner":[],"postedDate":"December 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-12-17T03:30:56+00:00","versionOfRecord":[],"versionCreatedAt":"2024-12-17 03:30:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5550147","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5550147","identity":"rs-5550147","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}