Efficacy of indigenous strain of entomopathogenic nematode against diapausing larvae of Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), in apple-growing hilly areas of Ladakh Region

Abstract

Indigenous entomopathogenic nematode, Heterorhabditis pakistanensis, NBAIR H-05 strain was evaluated against diapausing larvae of the Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae) at 3 different dosages, i.e., at 15, 20, and 25 gm/ l of water in apple orchards at the district Kargil of Ladakh Region, India, during 2017 and 2018.Two year’s pooled average density of diapausing ranged 34.6 to 56.8 larvae/trunk band before treatment, which declined ranging 43.85 to 86.27 % with respect to different treatments of entomopathogenic nematode at concentrations between 7.5 × 105 IJs to 1.25 × 106 IJs/tree. Percent reduction in larvae over control varied from 41.78 to 85.77% for 7.5 × 105 IJs and 1.25 × 106 IJs respectively. Two-year pooled data indicated larval mortality between 39.85 and 73.38% and 4.0 to 12.89% with respect to different treatments at 48 and 72 h respectively, with statistically significant difference (P = ˂ 0.001). Increase in dosage of nematode formulation from 15 gm to 25 gm resulted in increased larval mortality (r = 0.92**). Post wetting of trunk band after 24 h in each treatment resulted in significantly higher larval mortality than non-post wetting. There was non-significant difference (t = 0.83) between larval mortality with respect to treatments during 2017 and 2018.