寄主体型大小对管氏肿腿蜂生殖潜力的影响

Influence of host body size on potential reproductive capability of Sclerodermus guani( Hymenoptera: Bethylidae)

【目的】揭示寄主体型大小对肿腿蜂生殖潜力的影响,进一步认识寄生蜂准社会行为的进化以及为大规模繁殖和利用肿腿蜂的生物防治实践提供科学依据。【方法】以管氏肿腿蜂Sclerodermus guani和寄主青杨天牛Saperda populnea幼虫为材料,为雌蜂终身连续提供称重的寄主,观察逐日产卵量及在无抚育条件下其子代蜂发育至成虫的表现,分析产卵时期(早、中和晚期)、寄主体重对产卵量及其子代发育指标的影响。【结果】寄主体重和产卵期均影响管氏肿腿蜂终身产卵量,产卵量随寄主体重增大而呈二次函数式增大,但随产卵期延长而大幅减小。寄主体重和产卵期互作影响管氏肿腿蜂子代蜂存活率、岀蜂数、成虫体重和性比等子代发育指标,表现在:(1)产卵早期所产子代蜂的存活率随寄主体重增大而略降低,产卵中期所产子代蜂存活与寄主体重无关,产卵晚期所产子代蜂的存活率可能与寄主体重无关;(2)产卵早期和晚期产子代蜂的羽化成虫数和性比不受寄主体重的影响,但产卵中期产的子代蜂出蜂数随寄主体重增大而增加,性比随寄主体重增大而逐渐减小;(3)产卵早期产的子代雌蜂体重随寄主体重增大而呈二次函数式增大,而产卵中期产的子代蜂体重不受寄主体重的影响。【结论】寄主体型大小对管氏肿腿蜂早期产卵量及其子代蜂发育表现有显著影响。

【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.