Potential of indigenous strains of entomopathogenic nematodes under laboratory and Protected environment conditions for the control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) of North-Western Himalayas

Background: Entomopathogenic nematodes (EPNs) are a type of biological control agent that has been extensively studied. Under field and laboratory settings, the efficiency of two EPNs species, Heterorhabditis indica and Steinernema feltiae , isolated locally from soils of Rajghar, Himachal Pradesh, India, against an important invasive pest, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), was assessed. Results Steinernema feltiae (isolate- HR-1) and Heterorhabditis indica (isolate- HA-2) species dose (10, 20, 40, 80, 160 IJs/cm 2 ) are used in the lab bioassay. The third instar (percentage) ranges from 24.15 to 90.00 percent. HR1 and HA2 isolates demonstrated significant larvicidal activity with LC 50 , LC 75 , and LC 90 of all instars and pupa show high mortality from 31.53 to 90.00 percent and 72-hours exposure duration. The strain slows larval development in 48 to 72 hours of exposure period, with LC 50 values ranging from 05.42 to 19.29, LC 75 values ranging from 20.29 to 83.12, and LC 90 values ranging from 26.03 to 78.89. Greenhouse test seam isolates are foliar sprayed three times at a 14-day interval, with total findings revealing a 7.36 ore count range before spraying. The total treatment outcomes range from 1.64 to 1.74 for isolate HA-2, and 1.88 and 2.03 for HR-1. 4.15 percent was recorded in the control plot. Conclusion Invasive species pose a significant threat, as evidenced by this research. Traditional EPNs ( S. feltiae HR-1, H. indica HA-2) have been used as an active biocontrol agent in laboratory and greenhouse settings, as well as the pathogen that infects T. absoluta .