G Narendra Kumar
CCS Haryana Agricultural University, India
G Narendra Kumar presently pursuing his PhD in the discipline of Entomology from CCSHAU, Hisar, Haryana and is working on hygienic behavior in honey bees and resistance in Varroa to acaricides. He completed his M.Sc. programme from the same University in 2011. During M.Sc he conducted studies on the toxicity of various insecticides to Trichogramma chilonis. He has done his graduation in B.Sc. (Agriculture) from College of Agriculture, Bapatla under Acharya N. G. Ranga Agricultural University, Hyderabad, Andhra Pradesh in 2009. He actively participated in various literary competitions during B.Sc. and represented his university in the national debating completion held at Madurai, Tamil Nadu in 2009.
Investigations were carried out to assess the toxicity of insecticides on various biological parameters of Trichogramma chilonis Ishii. Spinosad was found to be the most toxic in all the laboratory studies followed by triazophos. Spinosad resulted in only 17.80 per cent parasitization and 3.97 per cent adult emergence from the eggs treated before parasitization. Novaluron was found to be the safest resulting in 58.93 per cent parasitization and 89.72 per cent adult emergence from the eggs treated before parasitization. The parasitization in other insecticides ranged from 20.00 to 40.47 per cent. Spinosad was also found highly toxic to all the immature stages resulting in only 0.46, 0.66 and 0.65 per cent adult emergence from the egg, larval and pupal stages, respectively, while novaluron was found to be safe to all the immature stages resulting in 86.75, 87.84 and 87.46 per cent adult emergence from the egg, larval and pupal stages, respectively. The adult emergence in other insecticides ranged from 57.95 to 88.63 per cent from egg stage, 53.97 to 87.12 per cent from larval stage and 61.46 to 87.15 per cent from pupal stage. In residual toxicity studies under laboratory conditions only novaluron was found to be safe while all the other insecticides remained toxic even up to 15 days of preparation of film while residual toxicity studies under field conditions resulted in the recommendation of minimum waiting period of 10 days for endosulfan, imidacloprid and azadirachtin and 15 days for thiodicarb while it was more than 15 days for spinosad and triazophos.