Effect of induced tolerance to Bt toxin on the egg size of Helicoverpa armigera and parasitism by Trichogramma pretiosum

摘要: Larvae of Helicoverpa armigera (Hubner) can develop a form Bt tolerance after exposure to sub-lethal doses Bt-toxin subclass Cry1Ac. Increasing levels are produced over generations larval exposure, which not related DNA sequence changes, and largely maternally transmitted. The characteristic maternal transmission, combined with the importance egg parasitoids cotton pest management, raises questions about effects tolerance/exposure on eggs H. some key metrics parasitism. In present study, effect inducible parasitism by Trichogramma pretiosum (Riley) is investigated. First, volumes laid susceptible tolerant females compared. addition, determined comparing success, number adult wasps emerged per host egg, proportion male female offspring egg. results obtained suggest that Cry1Ac-tolerance associated increased volume, even just one generation exposure. When freed from ongoing corresponding decrease in volume detected. Although there no difference percentage parasitized, an increase emergent parasitoids, especially males, armigera. These confirm maternally-transmitted reflected phenotype offspring, affects