Artificial diet based investigation on the impact of purified Cry1Ac, Cry1Fa and Cry2Ab on the survival and reproductive performance of adult green lacewing, Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae)

摘要

The green lacewing Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae) is a common and abundant predator in many cropping systems in palearctic realm and it's conservation is helpful in sustainable pest management in agro-ecosystem. Prior to commercialization of Bt crops in any agro- ecosystem, it is necessary to evaluate the impact of Cry proteins upon non-target organisms especially biological control agents (BCA). In present study an artificial diet consisting of shrimp, beef, beef liver and egg yolk was developed to mass-rear C. pallens for its use as biological control agents in sustainable pest management. Moreover, an artificial diet based risk assessment protocol was developed to investigate the impact of Cry1Ac, Cry1Fa and Cry2Ab on the survival and reproductive performance of C. pallens adults. C. pallens was fed on diets incorporated with Cry proteins and without addition of Cry proteins (control). The same diet containing boric acid was served as a positive control. Temporal stability, bioactivity and intake of Cry proteins by C. pallens were confirmed using double-antibody sandwich, enzyme-linked immunosorbent assay and bioactivity verification bioassays. Survival and reproductive performance of C. pallens, e.g., pre-oviposition period, daily fecundity, total fecundity and 30-day old adults dry weights, exhibited non-significant differences (p 0.05) for the diets containing Cry1Ac, Cry1Fa and Cry2Ab (50 mu g/g) against Control. However, significant reduction in survival and reproductive performance (p 0.05) was observed in positive control. Our findings reveal that artificial diet is a good source of nutritional requirement with enhanced survival and reproductive performance of C. pallens and can be used for mass rearing of predator in case of natural diet scarcity and Cry proteins are safe for adult C. pallens and Bt crops cultivation help in predators conservation in sustainable agriculture.