Impact of Cry1Ac and Cry2Ab Toxins on the Development of the Predator Chrysoperla zastrowi sillemi Through Prey-Mediated Tri-trophic Interactions.

Abstract

Adopting genetically modified crops in developing nations like India has consistently been hindered by apprehensions regarding their impact on non-target arthropods. Consequently, laboratory experiments were conducted to evaluate the impact of Bt toxins of BG-II cotton on the common green lacewing [Chrysoperla zastrowi sillemi (Esben-Petersen)], indirectly exposing them to the toxins. Prey-mediated feeding bioassays, utilizing BG-II cotton and non-Bt cotton plants as hosts, two prey herbivores, specifically Aphis gossypii Glover and Bemisia tabaci (Gennadius), were conducted on several days to assess the effects of Cry toxins on the growth of C. z. sillemi. The ELISA assay quantified the Cry toxins across three trophic levels and revealed that the leaves had the highest quantities of Cry1Ac and Cry2Ab toxins, measuring 7.36 and 23.54 µg/g FW, respectively. In contrast, herbivores and predators exhibited very low concentrations of Cry toxins. Although traces of Cry toxins were found in both herbivores and predators, they had no negative impacts on any of the predator's developmental characteristics including total larval development period, pupal period, adult weight, adult longevity, and fecundity/female confirming that these toxins do not threaten C. z. sillemi.