author(s)
Shaimaa AA Moamen, Emad MS Barakat and Mohamed O Abokersh

abstract
The present study investigated the quantitative assessments of hemolymph biochemical composition at different developmental stages of Galleria mellonella post-injection with a sub-lethal concentration of Bacillus thuringiensis (Bt). The estimated LC₅₀ values were 1.3×10⁵, 5.9×10⁵ and 4.6×10⁴ cells/ml for the larvae, pupae, and adults, respectively. Pupae were highly resistant, while the adults showed more susceptibility without any effect of sex on the response. The levels of carbohydrates, lipids, and proteins were of great value during the larval stage, followed by a reduction in the pupal stage finally a sharp decline had been observed in the adult ones. A time-dependent study revealed that the carbohydrate levels augmented significantly (P<0.05), while the levels of lipids and proteins reduced significantly at all developmental stages and there were no significant differences between males and females in their responses. Pupae and adults developed from previously treated stages showed no significant changes (P≥0.05) than treated insects. Finally, we deduced that adult was the more susceptible stage to begin the control strategies and the immune activation in the G. mellonella was transstadially transmitted from larvae to pupae and adults emerged from primary challenged stage.