Host location in Oomyzus gallerucae (Hymenoptera: Eulophidae), an egg parasitoid of the elm leaf beetle Xanthogaleruca luteola (Coleoptera: Chrysomelidae)
Host location in Oomyzus gallerucae (Hymenoptera: Eulophidae), an egg parasitoid of the elm leaf beetle Xanthogaleruca luteola (Coleoptera: Chrysomelidae)
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寄主位置为 Oomyzus gallerucae（膜翅目：Eulophidae），榆叶甲虫 Xanthogaleruca uteola（鞘翅目：叶甲科）的卵寄生蜂
DOI：
10.1007/s004420050287
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发表时间：
1997
期刊：
影响因子：
2.7
通讯作者：
M. Hilker
中科院分区：
文献类型：
--
作者：
T. Meiners;M. Hilker
摘要榆树叶甲卵经常受到褐斑潜蝇的严重危害。我们研究了卵寄生蜂、寄主和植物榆树之间相互作用的化学信号。嗅觉生物测定表明，寄主-植物复合体的挥发物吸引了该寄生蜂。为了确定寄主-植物复合体中诱人挥发物的来源，我们分别测试了卵、怀孕榆叶甲虫雌成虫、甲虫粪便和榆枝(未受损害的叶片和叶片被机械破坏或取食)的气味的影响。榆叶甲的粪便气味具有诱惑性，而卵挥发物和怀孕雌虫的挥发物均不起引诱作用。来自未受伤害或受害植物的挥发物不能在鸡眼蜂中引起阳性反应，而来自寄主卵子沉积在其上的取食受损植物的挥发物具有诱惑力。这一结果表明，寄主卵子不是取食，而是沉积在榆树叶片上，诱导产生对卵寄生蜂有吸引力的植物挥发物。用实验室生物测定方法对栖息地内的鸡眼蜂的搜索模式进行了调查，结果表明，卵寄生蜂与寄主卵偶然相遇。从粪便中分离的接触性凯诺酮在微生境接受中起重要作用，而从寄主卵子中分离的接触性凯诺酮与宿主识别有关。
Abstract Eggs of the elm leaf beetle Xanthogaleruca luteola are often heavily attacked by the chalcidoid wasp Oomyzus gallerucae. We studied the chemical signals mediating interactions between the egg parasitoid, its host, and the plant Ulmus campestris. Olfactometer bioassays with O. gallerucae showed that volatiles of the host-plant complex attract the parasitoid. In order to determine the source of attractive volatiles within this host-plant-complex, we tested separately the effect of odours of eggs, gravid elm leaf beetle females, faeces of the beetles and elm twigs (with undamaged leaves and leaves damaged either mechanically or by feeding of the beetles). Odours of faeces of the elm leaf beetle were attractive, whereas neither volatiles from eggs nor from gravid females acted as attractants. Volatiles from undamaged or damaged plants did not elicit a positive reaction in O. gallerucae, whereas volatiles from feeding-damaged plants onto which host eggs had been deposited were attractive. This latter result suggests that it is not feeding but deposition of host eggs onto elm leaves that induces the production of plant volatiles attractive to the egg parasitoid. Investigations of the search patterns of O. gallerucae within the habitat by laboratory bioassays revealed that the egg parasitoid encounters host eggs by chance. Contact kairomones from faeces were demonstrated to be important in microhabitat acceptance, while contact kairomones isolated from the host eggs are relevant for host recognition.