Department of Plant Protection Biology, Chemical Ecology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
PLoS One. 2011;6(10):e25658. doi: 10.1371/journal.pone.0025658. Epub 2011 Oct 3.
Organisms are attacked by different natural enemies present in their habitat. While enemies such as parasitoids and predators will kill their hosts/preys when they successfully attack them, enemies such as micropredators will not entirely consume their prey. However, they can still have important consequences on the performance and ecology of the prey, such as reduced growth, increased emigration, disease transmission. In this paper, we investigated the impact of a terrestrial micropredator, the yellow fever mosquito Aedes aegypti, on its unusual invertebrate host, the Egyptian cotton leaf worm, Spodoptera littoralis. Larvae developing in presence of mosquitoes showed a slower development and reached a smaller pupal weight when compared to a control without mosquitoes, apparently because of a reduced feeding time for larvae. In addition, larvae tended to leave the plant in presence of mosquitoes.These results suggest that mosquitoes act as micropredators and affects lepidopteran larvae behaviour and development. Ecological impacts such as higher risks of food depletion and longer exposure to natural enemies are likely to be costly consequences. The importance of this phenomenon in nature - the possible function as last resort when vertebrates are unavailable - and the evolutionary aspects are discussed.
生物受到其栖息地中存在的不同天敌的攻击。当寄生蜂和捕食者等天敌成功攻击它们的宿主/猎物时，它们会杀死宿主/猎物，而像微捕食者这样的天敌则不会完全消耗它们的猎物。然而，它们仍然会对猎物的表现和生态产生重要影响，例如生长减缓、迁徙增加、疾病传播。在本文中，我们研究了一种陆生微捕食者，即黄热病蚊子埃及伊蚊，对其不寻常的无脊椎动物宿主埃及棉铃象鼻虫 Spodoptera littoralis 的影响。与没有蚊子的对照相比，在蚊子存在的情况下发育的幼虫生长缓慢，蛹重较小，显然是因为幼虫的进食时间减少了。此外，幼虫在有蚊子的情况下往往会离开植物。这些结果表明，蚊子作为微捕食者影响鳞翅目幼虫的行为和发育。食物枯竭风险增加和更长时间暴露于天敌等生态影响可能是代价高昂的后果。讨论了这种现象在自然界中的重要性——当脊椎动物不可用时可能作为最后的手段——以及进化方面。
