Wiskerke J S C, Dicke M, Vet L E M
Department of Entomology, Wageningen Agricultural University, P.O. Box 8031, 6700 EH, Wageningen, The Netherlands.
Oecologia. 1993 Feb;93(1):145-148. doi: 10.1007/BF00321204.
Parasitoids that forage for herbivorous hosts by using infochemicals may have a problem concerning the reliability and detectability of these stimuli: host stimuli are highly reliable but not very detectable at a distance, while stimuli from the host's food are very detectable but generally not very reliable in indicating host presence. One solution to this problem is to learn to link highly detectable stimuli to reliable but not very detectable stimuli. Ample knowledge is available on how associative learning aids foraging parasitoids in the location of suitable microhabitats. However, in this paper we report on another solution to the reliability-detectability problem and present evidence for an essential, but as yet overlooked, aspect of Drosophila parasitoid ecology. For the first time it is shown that a parasitoid of Drosophila larvae spies on the communication system of adult Drosophila flies to locate potential host sites: naive parasitoids strongly respond to a volatile aggregation pheromone that is deposited in the oviposition site by recently mated female flies. Thus, the parasitoids resort to using highly detectable information from a host stage different from the one under attack (i.e. infochemical detour). The function and ecological implications of these findings are discussed.
通过利用信息化合物来搜寻草食性寄主的寄生蜂，可能会在这些刺激物的可靠性和可探测性方面遇到问题：寄主刺激物高度可靠，但在一定距离外很难被探测到；而来自寄主食物的刺激物很容易被探测到，但在指示寄主存在方面通常不太可靠。解决这个问题的一个办法是学会将易于探测的刺激物与可靠但难以探测的刺激物联系起来。关于联想学习如何帮助寄生蜂在合适的微生境中觅食，已有丰富的知识。然而，在本文中，我们报告了可靠性 - 可探测性问题的另一种解决方案，并提供证据证明果蝇寄生蜂生态学中一个重要但迄今被忽视的方面。首次表明，果蝇幼虫的寄生蜂会窥探成年果蝇的通讯系统以定位潜在的寄主位点：未接触过该信息的寄生蜂会对最近交配的雌蝇在产卵位点沉积的挥发性聚集信息素产生强烈反应。因此，寄生蜂转而利用来自与被攻击阶段不同的寄主阶段的易于探测的信息（即信息化合物迂回策略）。我们讨论了这些发现的功能和生态意义。
