Department of Terrestrial Ecology, Netherlands Institute of Ecology, Droevendalsesteeg 10, Wageningen, The Netherlands.
J Insect Physiol. 2012 Nov;58(11):1463-8. doi: 10.1016/j.jinsphys.2012.08.013. Epub 2012 Aug 28.
Parasitoid wasps are model organisms for exploring constraints on life history and development strategies in arthropods. Koinobiont parasitoids attack hosts that may vary considerably in size at parasitation. Thus far, studies exploring koinobiont development in hosts of different size have been exclusively done with primary parasitoids attacking insect herbivores. However, the larvae of primary koinobiont parasitoids may in turn be attacked by koinobiont hyperparasitoids. We examined development of the gregarious hyperparasitoid Baryscapus galactopus in different stages of its primary parasitoid host, Cotesia glomerata, itself developing in different stages of caterpillars of the cabbage butterfly, Pieris brassicae. This is the first study exploring hyperparasitoid development in different stages of a primary and secondary host. Second instar (L2) larvae of P. brassicae were parasitized by C. glomerata, and separate cohorts of L3 to L5 P. brassicae containing different stages of C. glomerata were then presented to B. galactopus females. B. galactopus was able to parasitize tiny larvae of C. glomerata in L3 caterpillars of P. brassicae, but hyperparasitism efficiency increased in later instars of both C. glomerata and P. brassicae. Development time of B. galactopus was extended in younger C. glomerata/P. brassicae hosts, whereas adult mass was largest when C. glomerata was attacked in L3 through early L5 P. brassicae. Our results show that B. galactopus adjusts its development rate in accordance with the size of both its primary and secondary hosts, in order to ensure survival. Adaptive responses to phylogenetic constraints on the development of primary hyperparasitoids are discussed.
寄生蜂是研究节肢动物生活史和发育策略制约因素的模式生物。共生寄生蜂攻击的宿主在寄生时大小可能有很大差异。迄今为止，研究共生发育的研究仅限于以攻击昆虫食草动物的初级寄生蜂为主。然而，初级共生寄生蜂的幼虫可能反过来会被共生超寄生蜂攻击。我们研究了群居超寄生蜂 Baryscapus galactopus 在其初级寄生蜂宿主 Cotesia glomerata 的不同发育阶段的发育情况，而 C. glomerata 本身则在甘蓝菜粉蝶幼虫的不同阶段发育。这是第一项研究共生超寄生蜂在初级和次级宿主不同阶段发育的研究。小菜粉蝶的第二龄（L2）幼虫被 C. glomerata 寄生，然后将不同龄期的 L3 到 L5 小菜粉蝶幼虫与 C. glomerata 分开，提供给 B. galactopus 雌蜂。B. galactopus 能够寄生在小菜粉蝶 L3 幼虫中非常小的 C. glomerata 幼虫，但在 C. glomerata 和小菜粉蝶的后期龄期，超寄生效率增加。B. galactopus 在较年轻的 C. glomerata/小菜粉蝶宿主中的发育时间延长，而当 C. glomerata 在 L3 到早期 L5 小菜粉蝶中受到攻击时，成虫的质量最大。我们的研究结果表明，B. galactopus 根据其初级和次级宿主的大小调整其发育速度，以确保生存。讨论了对初级超寄生蜂发育的系统发育制约因素的适应性反应。
