Mitigation of Insecticide Resistance in Helicoverpa armigera (Hubner) (Lepidoptera:Noctuidae) by Conjunctive Use of Trap Crops, Neem and Trichogramma chilonis Ishii in Cotton
Push-pull strategy with conjunctive use of trap crops, neem and Trichogramma chilonis Ishii was evaluated against cotton bollworm, Helicoverpa armigera (Hubner) under field conditions. Neem seed kernel extract (NSKE) was applied on cotton crop leaving trap crops (okra and pigeonpea) commencing from 46 DAS at weekly interval to increase the pushing of H. armigera away from cotton. Application of NSKE on cotton improved the oviposition preference ratio from 1:1.35 and 1:1.40 to 1:3.02 and 1:2.43 on cotton:okra and cotton:pigeonpea, respectively. Egg parasitoid, T. chilonis cards were tagged after each application of NSKE on the trap crops. The percent parasitism of eggs of H. armigera on cotton sole crop system ranged from 14.8 to 16.4% and that on trap crops was 10.4 to 12.0 and 14.5 to 15.5% on okra and pigeonpea respectively. Cotton (treated with NSKE) + Trap crops (Trichogramma released) system recorded the lowest mean egg, larval population and fruiting bodies, boll and locule damage. The synthetic pyrethroids resistance in field survived H. armigera at the end of the season was reduced from 85.3-94.0 to 84.8 -92.1%.
Cited References Fulltext