Impact of some selected insecticides and bio-pesticides on incidence of predators, parasitoid and productivity of lac insect, Kerria lacca

Abstract

Two lepidopteran predators, Eublemma amabilis and Pseudohypatopa pulverea and Aprostocetus purpureus an endoparasitoid have emerged as a major threat to lac cultivation. The objectives of the current study were to identify some potential insecticides and bio-pesticides against major biotic stress of lac crop. Field evaluation of spinosad 2.5SC, indoxacarb 14.5SC, fipronil 5SC, ethofenprox 10EC and three commercial formulations of Bacillus thuringiensis var. kurstaki on rangeeni and kusmi lac culture reveal significant reduction in incidence of Eublemma amabilis and Pseudohypatopa pulverea attacking Kerria lacca. The reduction in incidence of E. amabilis ranged from 42.47 - 96.24% and 65.00 95.00% and P. pulverea ranged from 52.50 - 97.50% and 66.67 - 100.00% during rangeeni rainy and summer crop, respectively. The reduction in the incidence of E. amabilis and P. pulverea on kusmi winter lac crop recorded to the tune of 61.02 - 93.55% and 12.86 - 98.57%, respectively whereas, on kusmi summer crop it was 56.16 to 95.52% and 66.17 to 98.50%, respectively. Productivity of lac increased to the tune of 78.95 to 168.42% and 11.40 to 36.84% in kusmi winter and summer lac crop, respectively whereas 33.33 to 166.67% in rangeeni rainy lac crop. Higher fecundity and superior quality broodlac was obtained from treated crops. Insecticides, spinosad, indoxacarb, fipronil, ethofenprox and bio-pesticides therefore can be used for effective suppression of predators attacking lac culture.