关键词: 肿腿蜂, 管氏肿腿蜂, 青杨天牛, 寄主品质, 终身生殖力, 发育表现, 性比

Abstract: 【Aim】 To explore the effects of host body size on potential reproductive capability of Sclerodermus guani, and so to provide data for understanding the quasi-social behavior evolution in parasitoids and mass production of Sclerodermus parasitoids in biological control of wood-boring beetle pests. 【Methods】 We exposed a larva of the small poplar longhorn beetle, Saperda populnea to a female adult of S. guani to oviposit each day until the wasp was dead. Number of eggs laid every day and offspring developmental performance without maternal care were analyzed in relation to host body weight at parasitism and oviposition periods (early, middle and late periods). 【Results】 The number of eggs laid by S. guani was affected not only by host body weight at parasitism, increasing in a quadratic function with host weight, but also by the oviposition period, decreasing distinctly from early to late periods. Offspring developmental performance of this parasitoid, as measured by the survival rate, number of emerged adults, adult body weight and sex ratio, was influenced by interactions between host body weight and oviposition period. Survival of offspring parasitoids slightly decreased with increasing host body weight for the eggs laid in the early period, but did not vary for the eggs laid in the middle and likely late periods. The number and sex ratio of emerged adults were not affected by host body weight for the eggs oviposited in the early and late periods, but the number of emerged wasps increased and sex ratio decreased with host body weight for the eggs laid in the middle period. Offspring female adult body weight increased with host body weight in a quadratic function for the eggs produced in the early oviposition period, but did not vary for the eggs laid in the middle period. 【Conclusion】 Host body size has a profound influence on the number of eggs laid and developmental performance of offspring parasitoids from the eggs laid in the early ovipositon period.

Key words: Bethylid wasps, Sclerodermus guani, Saperda populnea, host quality, lifetime fecundity, developmental performance, sex ratio