摘要
研究寄生蜂对寄主不同龄期的寄生策略通常采用适温下(≈25℃)培养的寄主进行试验。为探究蚜茧蜂对高温下生长的寄主蚜虫的寄生反应及其适合度表现,在30℃条件下饲养寄主孤雌胎生无翅黑豆蚜Aphis fabaeScopli,获得不同龄期若蚜和刚羽化的成蚜,分别提供给可疑柄瘤蚜茧蜂Lysiphlebus ambiguus Haliday寄生,观察蚜茧蜂的寄生率以及后代性比、体型大小和发育时间等适合度相关特性。结果表明:可疑柄瘤蚜茧蜂对1至4龄若蚜及成蚜均寄生,但偏向寄生较早龄期的若蚜,对成蚜的寄生率为28.0%,显著低于对1龄(40.0%)和2龄(42.8%)寄主若蚜的寄生率。后代雌蜂比例和体型随寄主龄期(体型)增大而减小,而发育历期则呈现"中间低,两头高"的格局。后代性比、体型大小及发育历期等适合度表现与此前适温(≈25℃)下得到的结果截然相反。因此推测,寄主黑豆蚜体型或龄期可能不是或不全部是可疑柄瘤蚜茧蜂评价寄主质量的依据,其他与寄主蚜虫内共生菌动态相关的线索(如行为的,化学的等)可能才是其评价寄主质量的依据。
Prevalent experiments to investigate the host-stage selection of parasitoids manipulate host cohorts at the optimal temperature （≈25℃）. To explore the oviposition strategy and fitness-related performances of parasitoids in different host instars, the black bean aphid, Aphisfabae Scopli was cultured at 30℃ to obtain cohorts of different instars and adults and then exposed to parasitism of Lysiphlebus ambiguus （Haliday）. The parasitism and fitness-related performances were recorded including parasitization rate, emergence rate, sex ratio, body size, and development time. The results indicated that the aphid parasitoid attacked more young aphids than the old, even though the 1 st through the 4th instar nymphs and eclosing adults were all susceptible to parasitism. The parasitism rate on the adult aphid （28.0%） was significantly lower than on the 1st instar nymph （40.0%） and the 2nd instar nymph （42.8%）. The proportion of female progeny and emerging adult size of the offspring parasitoid declined with the increase of aphid instars （and body sizes） at parasitism, but the development time remained constant, which contrasted with fitness performances of the parasitoid attacking the host reared at the optimal temperature. It was argued that L. ambiguus may not or may not always base the host value on body size and instar of the host, and other clues （e. g. behavioral, chemical etc. ） associated with dynamics of endosymbiotic bacteria in the host aphid should be considered.
出处
《昆虫学报》
CAS
CSCD
北大核心
2007年第5期488-493,共6页
Acta Entomologica Sinica
基金
国家自然科学基金项目(30370237)
