春臀钩土蜂两个地理种和日本丽金龟臀钩土蜂搜索能力的比较

利用“Y”型选择器和草地寄主搜寻试验，就春臀钩土蜂两个品系和日本丽金龟瞥钩土蜂对日本金龟子的搜索能力进行了比较。结果表明，两种土蜂的3个品系对日本金龟子3龄幼虫的存在与否没有表现出明显的辨别能力。虫粪对土蜂搜索寄主有一定的引导作用，但日本丽金龟臀钩土蜂的趋性没有春臀钩土蜂明显。寄主虫体气味与虫粪混合存在比只有虫粪存在更能吸引土蜂。土蜂可以在相隔两个侧臂20cm的距离内感知金龟子幼虫的存在；当寄主与非寄主金龟子同时存在时，不能辨别出寄主；但能通过虫粪辨认寄主所在方向。春臀钩土蜂两个品系对日本金龟子幼虫气味表现出极强的趋性。日本丽金龟臀钩土蜂则受非寄主幼虫气味干扰。草地寄主搜寻试验表明，春臀钩土蜂CH—SD品系仅搜索内开口隧道内幼虫；A—NC品系对隧道的开口没有表现出特殊的选择性。67．5％雌蜂能够感知寄主幼虫的存在并自行挖洞搜索。寄主粪便可以引导土蜂从人工隧道开口进入。网罩内草地上的虫粪可以干扰土蜂对地下寄主位置的判断。

Host Searching Ability Comparison Between Tiphia popilliavora and Two Geographical Strains of Tiphia vernalis

Host searching for Tiphia sp.by T.popilliavora and two geographical strains of T.vernalis were compared by Y olfactometer and field experiment. It was found that three strains of the 2 Tiphia species could not perceive the existence of host white grub third instar larvae per se,but T.vernalis[KG*2/5]was more sensitive to host frass than T.popilliavora and odor collected from host larvae and frass was more attractive to Tiphia spp.than frass odor only.The wasps could not tell host from non-host larvae within the distance of the sealed channel that was filled with sandy soil,but could orient to their host's box when there were host frass.When larvae odor of host and non-host coexisted,T.vernalis could locate its host but T.popilliavora hesitated,apparently confused by non-host larvae odor.67.5% of the test population of T.vernalis geographical strains A-NC dug into under grass channel and find host out,no matter there was a mouth existed in the cage or not,but T.vernalis geographical strains of CH-SD test channel only through the mouth.Frass placed around the mouth could be the clue that attracts wasps to dig into host channel,nevertheless,frass sprinkled randomly on grass lacked the function of host location indicator.