Department of Terrestrial Ecology, Netherlands Institute of Ecology, Heteren, The Netherlands.
J Insect Physiol. 2010 Sep;56(9):1178-83. doi: 10.1016/j.jinsphys.2010.03.018. Epub 2010 Mar 31.
Solitary koinobiont endoparasitoids generally reduce the growth of their hosts by a significant amount compared with healthy larvae. Here, we compared the development and host usage strategies of the solitary koinobiont endoparasitoid, Meteorus pulchricornis, when developing in larvae of a large host species (Mythimna separata) and a much smaller host species (Plutella xylostella). Caterpillars of M. separata were parasitized as L2 and P. xylostella as L3, when they weighed approximately 2mg. The growth of parasitized M. separata larvae was reduced by almost 95% compared with controls, whereas parasitized P. xylostella larvae grew some 30% larger than controls. Still, adult wasps emerging from M. separata larvae were almost twice as large as wasps emerging from P. xylostella larvae, had larger egg loads after 5 days and produced more progeny. Survival to eclosion was also higher on M. separata than on P. xylostella, although parasitoids developed significantly faster when developing on P. xylostella. Our results provide evidence that koinobionts are able to differentially regulate the growth of different host species. However, there are clearly also limitations in the ability of parasitoids to regulate phenotypic host traits when size differences between different host species are as extreme as demonstrated here.
与健康幼虫相比，独居共生内寄生蜂通常会使宿主的生长显著减少。在这里，我们比较了独居共生内寄生蜂，丽草蛉茧蜂，在大型宿主物种（粘虫）和小得多的宿主物种（小菜蛾）的幼虫中发育时的发育和宿主利用策略。当它们的体重约为 2mg 时，丽草蛉茧蜂寄生粘虫的 L2 幼虫和小菜蛾的 L3 幼虫。与对照相比，寄生的粘虫幼虫的生长减少了近 95%，而寄生的小菜蛾幼虫的生长比对照大约 30%。尽管如此，从粘虫幼虫中羽化的成年蜂几乎是从小菜蛾幼虫中羽化的蜂的两倍大，5 天后产卵量更大，并产生更多的后代。在粘虫上的羽化存活率也高于小菜蛾，但当丽草蛉茧蜂在小菜蛾上发育时，它们的发育速度明显更快。我们的研究结果表明共生体能够有差异地调节不同宿主物种的生长。然而，当不同宿主物种之间的大小差异如这里所展示的那样极端时，寄生蜂调节表型宿主特征的能力显然也存在限制。
