Bolton L Grant, Piñero Jaime C, Barrett Bruce A
Division of Plant Sciences, University of Missouri, Columbia, MO.
Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA.
Environ Entomol. 2019 Sep 30;48(5):1049-1055. doi: 10.1093/ee/nvz092.
The spotted-wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is attracted to numerous volatile organic compounds (VOCs) emitted from several ripening, small fruit crops. However, the strawberry leaf terpenoid, β-cyclocitral, is reportedly very attractive to D. suzukii (but not to all Drosophila spp.). This suggests that leaf and fruit VOCs may be critical sources needed to further develop a more species-specific D. suzukii monitoring lure, or semiochemically based attract-and-kill systems. This study investigated the electrophysiological responses of male and female D. suzukii towards selected host fruit-ripening VOCs and β-cyclocitral, along with behavioral responses toward combined fruit VOCs with β-cyclocitral. Electroantennogram (EAG) results revealed a positive dose-response, for both sexes, as concentrations increased for all VOCs tested. For β-cyclocitral, hexyl acetate and methyl butyrate, the mean male EAG responses were significantly greater than the female responses at lower doses. In caged behavioral bioassays, only in the β-cyclocitral treatments were the mean number of flies captured (sexes combined) significantly greater than that captured in solvent (mineral oil) controls. Our study has demonstrated that while single fruit-based VOCs alone are not enough to cause a strong behavioral attraction by both male and female D. suzukii, the addition of β-cyclocitral did produce a significant attraction response from both sexes. In both bioassays, males had higher responses to β-cyclocitral than females, which suggest a greater sensitivity to this compound. Further studies are needed to ascertain the role β-cyclocitral may play in the development of a more species-specific D. suzukii monitoring lure.
斑翅果蝇，铃木氏果蝇（Drosophila suzukii Matsumura，双翅目：果蝇科），会被几种成熟的小型水果作物释放的多种挥发性有机化合物（VOCs）所吸引。然而，据报道草莓叶类萜β - 环柠檬醛对铃木氏果蝇极具吸引力（但并非对所有果蝇物种都有吸引力）。这表明叶片和果实VOCs可能是进一步开发更具物种特异性的铃木氏果蝇监测诱饵或基于信息化学物质的诱捕杀灭系统所需的关键来源。本研究调查了铃木氏果蝇雌雄个体对选定的寄主果实成熟VOCs和β - 环柠檬醛的电生理反应，以及对β - 环柠檬醛与果实VOCs混合物的行为反应。触角电位（EAG）结果显示，随着所有测试VOCs浓度的增加，雌雄个体均呈现正剂量反应。对于β - 环柠檬醛、乙酸己酯和丁酸甲酯，在较低剂量下，雄性的平均EAG反应显著大于雌性。在笼养行为生物测定中，只有在β - 环柠檬醛处理组中捕获的果蝇平均数量（雌雄合计）显著高于溶剂（矿物油）对照组。我们的研究表明，虽然单一的基于果实的VOCs不足以引起铃木氏果蝇雌雄个体强烈的行为吸引，但添加β - 环柠檬醛确实引起了两性的显著吸引反应。在两种生物测定中，雄性对β - 环柠檬醛的反应均高于雌性，这表明雄性对该化合物的敏感性更高。需要进一步研究以确定β - 环柠檬醛在开发更具物种特异性的铃木氏果蝇监测诱饵中可能发挥的作用。
