Raffa K F, Dahlsten D L
Department of Entomology, University of Wisconsin, 53706, Madison, WI, USA.
Division of Biological Control, University of California, 94720, Berkeley, CA, USA.
Oecologia. 1995 Apr;102(1):17-23. doi: 10.1007/BF00333305.
Predators that exploit prey pheromones may select for relatively subtle chemical changes that confer partial escape yet retain intraspecific functionality. Parallel experiments conducted with a transcontinentally distributed bark beetle, Ips pini, demonstrated that the most abundant predators in California and Wisconsin were more attracted to prey from distant sources than to those from local sources. Conversely, local I. pini populations were most attractive to local conspecifics. Any benefits to prey are probably only partial and temporary, however, because all predators showed some attraction to both I. pini populations. Responses by other insects exploiting I. pini communication systems varied with ecological guild. A parasitic wasp that attacks adult hosts was more attracted to local than to distant I. pini populations. Secondary subcortically feeding herbivores that cannot colonize living trees but rather breed in trees killed by I. pini were highly attracted to infested logs but did not consistently prefer either I. pini population source. Some possible underlying mechanisms, implications for natural enemy-prey coevolution, and suggested strategies for biological control are discussed.
利用猎物信息素的捕食者可能会选择相对细微的化学变化，这些变化能带来部分逃脱的能力，同时保留种内功能。对一种分布于两大洲的树皮甲虫——松果梢斑螟（Ips pini）进行的平行实验表明，加利福尼亚州和威斯康星州数量最多的捕食者对来自远处的猎物比对来自本地的猎物更感兴趣。相反，当地的松果梢斑螟种群对本地同种个体最具吸引力。然而，猎物获得的任何益处可能都只是部分的和暂时的，因为所有捕食者对这两个松果梢斑螟种群都表现出了一定的吸引力。利用松果梢斑螟通讯系统的其他昆虫的反应因生态类群而异。一种攻击成年寄主的寄生蜂对本地松果梢斑螟种群的吸引力比对远处种群的吸引力更大。以皮层下为食的次生食草动物无法在活树上定殖，而是在被松果梢斑螟杀死的树木中繁殖，它们对受侵染的原木极具吸引力，但并不总是更偏好某一个松果梢斑螟种群来源。本文讨论了一些可能的潜在机制、对天敌 - 猎物协同进化的影响以及生物防治的建议策略。
