Natural Enemies of Cotton Whitefly, Bemisia tabaci Gennadius in Relation to Host Population and Weather Factors

Abstract

The nymphal parasitism of whiteny, Bemisia tabaci Gennadius due to Eretmocerus serius , Eretmocerus sp. and an aphelinid reached 27.4 and 40.2 per cent while the predators Brumoides suturalis (F), Verania vincta , Menochilus sexmaculatus, Chrysoperla carnea (Steph.), Amblyseiuss pp. were at a level of 10.8 and 17.1 numbers per 10 leaves during January and November respectively. The incidence of fungal pathogens viz. Aspergillus sp., Paecilomyces sp. and Fusarium sp., of whitefly was high during November month by suppressing adults, nymphs and eggs to the extent of 86.6, 19.0 and 39.8 per cent respectively. In line with pest population, the parasites were also Influenced by the rainfall which showed significant negative correlations (r  =  0.4275 and 0.3971 respectively). The temperatures also showed a significant correlation with the parasitism, predatory population and mortality due to fungal pathogens.