Bt crops expressing Cry1Ac, Cry2Ab and Cry1F do not harm the green lacewing, Chrysoperla rufilabris

The green lacewing, Chrysoperla rufilabris (Burmeister), is considered an important natural predator due to its wide geographic distribution and its voracious larval feeding capacity. Its larvae feed on soft-bodies arthropods in many different crop habitats. Thus, C. rufilabris may be exposed to insecticidal proteins from Bacillus thuringiensis (Bt) when they are expressed in genetically engineered crops. Laboratory experiments were conducted to evaluate the prey-mediated impacts of Bt broccoli (expressing Cry1Ac), Bt cotton (expressing Cry1Ac/Cry2Ab) and Bt maize (expressing Cry1F) on several fitness parameters of C. rufilabris over two generations using Bt-resistant cabbage lopper, Trichoplusia ni, and Bt-resistant fall armyworm, Spodoptera frugiperda (JE Smith), larvae as prey. ELISA and sensitive-insect bioassays confirmed that C. rufilabris were exposed to bioactive Bt proteins. Development time of larval and pupal stages, female fecundity and egg hatching rate of C. rufilabris were not different when they fed on Bt-resistant prey reared on either Bt or non-Bt crops leaves for both generations. Our results demonstrate that Cry1Ac broccoli, Cry1Ac/Cry2Ab cotton and Cry1F maize do not affect C. rufilabris.