Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6700 EH Wageningen, The Netherlands; Department of Ecological Sciences - Animal Ecology, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Laboratory of Entomology, Wageningen University, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands.
J Insect Physiol. 2018 May-Jun;107:110-115. doi: 10.1016/j.jinsphys.2018.03.006. Epub 2018 Mar 16.
Among parasitoids that develop inside the bodies of feeding, growing hosts (so-called 'koinobiont' endoparasitoids), two strategies have evolved to dispose of host resources. The larvae of one group consumes most host tissues before pupation, whereas in the other the parasitoid larvae consume only host hemolymph and fat body and at maturity emerge through the host cuticle to pupate externally. Here we compared development and survival (to adult emergence) of two related larval endoparasitoids (Braconidae: Microgastrinae) of the diamondback moth, Plutella xylostella. Larvae of Dolichogenidea sicaria are tissue feeders whereas larvae of Cotesia vestalis are hemolymph feeders. Here, development of P. xylostella and the two parasitoids was compared on three populations (one cultivar [Cyrus], two wild, [Winspit and Kimmeridge]) of cabbage that have been shown to vary in direct defense and hence quality. Survival of P. xylostella and C. vestalis (to adult eclosion) did not vary with cabbage population, but did so in D. sicaria, where survival was lower when reared on the wild populations than on the cultivar. Furthermore, adult herbivore mass was significantly higher and development was significantly shorter in moths reared on the cultivar. The tissue-feeing D. sicaria was larger but took longer to develop than the hemolymph-feeder C. vestalis. The performance of both parasitoids was better on the cabbage cultivar than on the wild populations, although the effects were less apparent than in the host. Our results show that (1) differences in plant quality are diffused up the food chain, and (2) the effects of host quality are reflected on the development of both parasitoids.
在以取食、生长的宿主（所谓的“共生物”内生寄生蜂）体内发育的寄生蜂中，已经进化出两种处理宿主资源的策略。一组幼虫在化蛹前消耗大部分宿主组织，而另一组寄生蜂幼虫仅消耗宿主血液和脂肪体，在成熟时通过宿主表皮出壳化蛹。在这里，我们比较了两种相关的小菜蛾幼虫内生寄生蜂（Braconidae: Microgastrinae）的发育和生存（到成虫出现）。Dolichogenidea sicaria 的幼虫是组织取食者，而 Cotesia vestalis 的幼虫是血液取食者。在这里，我们比较了三种甘蓝种群（一个品种[Cyrus]，两个野生种群[Winspit 和 Kimmeridge]）上小菜蛾和两种寄生蜂的发育情况，这些种群在直接防御方面存在差异，因此在质量上也存在差异。小菜蛾和 C. vestalis（到成虫羽化）的存活率不因甘蓝种群而异，但 D. sicaria 的存活率则不同，在饲养于野生种群时，其存活率低于品种。此外，在品种上饲养的飞蛾的取食者质量明显更高，发育时间明显更短。取食组织的 D. sicaria 比血液取食的 C. vestalis 更大，但发育时间更长。尽管效果不如宿主明显，但两种寄生蜂在甘蓝品种上的表现均优于野生种群。我们的研究结果表明：（1）植物质量的差异在食物链中扩散，（2）宿主质量的影响反映在两种寄生蜂的发育上。
