Germinara Giacinto Salvatore, De Cristofaro Antonio, Rotundo Giuseppe
Department of the Sciences of Agriculture, Food and Environment, University of Foggia, Via Napoli 25, 71122 Foggia, Italy.
Department of Agricultural, Environmental and Food Sciences, University of Molise, Via De Sanctis, 86100 Campobasso, Italy.
Biomed Res Int. 2016;2016:5460819. doi: 10.1155/2016/5460819. Epub 2016 Jan 21.
Volatiles emitted by the host's food would be the first signals used by parasitoids in the host location process and are thought to play an important role in host habitat location. In this study, the olfactory responses of Theocolax elegans (Westwood), a Pteromalid wasp that parasitizes immature stages of stored-product insect pests developing inside cereal or leguminous grains, to volatiles emitted by healthy wheat grains, their hexane extracts, and different doses of three individual compounds previously identified in cereal grain odors were investigated in Y-tube olfactometer and Petri dish arena behavioral bioassays and electroantennogram recordings. In Y-tube olfactometer bioassays, odors from healthy wheat grains and their hexane extracts were attractive to both sexes of T. elegans. Moreover, hexane extracts elicited arresting effects in Petri dish arena. The three synthetic compounds valeraldehyde, maltol, and vanillin elicited dose-dependent responses in both male and female adult wasps confirming the capability of the peripheral olfactory systems to perceive cereal volatiles. In behavioral bioassays, different doses of vanillin were significantly attractive to both sexes.
寄主食物释放的挥发性物质是寄生蜂在寻找寄主过程中首先利用的信号，并且被认为在寄主栖息地定位中发挥重要作用。在本研究中，利用Y型嗅觉仪、培养皿行为生物测定法和触角电位记录，研究了寄生于谷物或豆类籽粒内发育的储藏物害虫未成熟阶段的褶翅小蜂科黄蜂——优雅细颚姬蜂（Theocolax elegans (Westwood)）对健康小麦籽粒释放的挥发性物质、其己烷提取物以及先前在谷物气味中鉴定出的三种单一化合物不同剂量的嗅觉反应。在Y型嗅觉仪生物测定中，健康小麦籽粒及其己烷提取物的气味对优雅细颚姬蜂的雌雄两性均具有吸引力。此外，己烷提取物在培养皿试验中产生了滞留效应。三种合成化合物戊醛、麦芽酚和香草醛在成年雌雄黄蜂中均引发了剂量依赖性反应，证实了外周嗅觉系统感知谷物挥发性物质的能力。在行为生物测定中，不同剂量的香草醛对雌雄两性均具有显著吸引力。
