Effect of Iranian Bt cotton on Encarsia formosa, parasitoid of Bemisia tabaci

ABSTRACT: Transgenic Bt cotton produces the Cry 1Ab toxin of Bacillus thuringiensis that developing against Helocoverpa armigera may be affected on secondary pest such as Bemisia tabaci. The laboratory experiments were conducted to evaluate the effects of direct or indirect exposure on the biology of non-target species. Also, we compared the performance of the parasitoid Encarsia formosa developing in secondary pest on two cotton lines including Bt cotton and control cotton (non transgenic cotton). The results indicated that the parasitoid immature mortality was not significantly affected by Bt cotton. Host plants significantly influenced development time up to adult for E. formosa. Parasitoid reached the adult stage faster on control cotton than Bt cotton. The transgenic cotton effects on Encarsia formosa were complex but generally interpretable in terms of host whitefly quality variation among host plants used as food by the whiteflies during their development.