Abstract: The effects of host eggs on Trichogramma dendrolimi and T. chilonis were investigated based on comparisons of the activities of carboxylesterase (CarE) and acetylcholinesterase (AChE) and their affinities toward substrates and sensitivities to insecticides. The activities of CarE in T. dendrolimi from Guangdong and Jilin Provinces reared on Antheraea pernyi eggs were lower than those of the same population reared on Corcyra cephalonica eggs, but the activity of CarE in T. chilonis from Hubei Province reared on A. pernyi eggs was higher than that reared on C. cephalonica eggs. The affinity of CarE to α-naphthyl acetate (α-NA) was higher in T. dendrolimi (Guangdong population) reared on A. pernyi eggs than those reared on C. cephalonica eggs. The affinity of AChE in the three Trichogramma populations reared on A. pernyi eggs was lower than that reared on C. cephalonica eggs. Comparing with the Trichogramma population reared on C. cephalonica eggs, the CarE of population reared on A. pernyi eggs was sensitive to SV1, and the sensitivity to paraoxon varied with the populations. The sensitivity of T. dendrolimi (Jilin population) AChE to DDVP and esterine using A. pernyi eggs as hosts was not significantly different from using C. cephalonica eggs as hosts, While, the AChE in T. dendrolimi (Guangdong population) and T. chilonis (Hubei population) reared on C. cephalonica eggs was more sensitive to DDVP and eserine than in those reared on A. pernyi eggs.

Key words: Trichogramma, host egg, carboxylersterase, acetylcholinesterase, insecticide