Gohole Linnet S, Overholt William A, Khan Zeyaur R, Pickett John A, Vet Louise E M
Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH Wageningen, The Netherlands.
J Chem Ecol. 2003 Mar;29(3):731-45. doi: 10.1023/a:1022828921763.
Olfactory responses of the cereal stemborer parasitoid Cotesia sesamiae to volatiles emitted by gramineous host and nonhost plants of the stemborers were studied in a Y-tube olfactometer. The host plants were maize (Zea mays) and sorghum (Sorghum bicolor), while the nonhost plant was molasses grass (Melinis minutiflora). In single-choice tests, females of C. sesamiae chose volatiles from infested and uninfested host plants and molasses grass over volatiles from the control (soil). In dual-choice tests, the wasp preferred volatiles from infested host plants to those from uninfested host plants. There was no discrimination between molasses grass volatiles and those of uninfested maize, uninfested sorghum, or infested maize. The wasp preferred sorghum volatiles over maize. Combining uninfested maize or sorghum with molasses grass did not make volatiles from the combination more attractive as compared to only uninfested host plants. Infested maize alone was as attractive as when combined with molasses grass. Infested sorghum was preferred over its combination with molasses grass. Local growth conditions of the molasses grasses influenced attractiveness to the parasitoids. Volatiles from Thika molasses grass were attractive, while those from Mbita molasses grass were not. Growing the Thika molasses grass in Mbita rendered it unattractive and vice versa with the Mbita molasses grass. This is a case of the same genotype expressing different phenotypes due to environmental factors.
在Y型嗅觉仪中研究了谷物蛀茎螟寄生蜂塞氏赛茧蜂对蛀茎螟禾本科寄主植物和非寄主植物释放的挥发物的嗅觉反应。寄主植物为玉米(Zea mays)和高粱(Sorghum bicolor),而非寄主植物为糖蜜草(Melinis minutiflora)。在单项选择试验中,塞氏赛茧蜂雌蜂选择来自受侵害和未受侵害寄主植物以及糖蜜草的挥发物,而不选择来自对照(土壤)的挥发物。在双项选择试验中,该黄蜂更喜欢来自受侵害寄主植物的挥发物而非未受侵害寄主植物的挥发物。对于糖蜜草挥发物与未受侵害玉米、未受侵害高粱或受侵害玉米的挥发物之间没有区分。该黄蜂更喜欢高粱挥发物而非玉米挥发物。将未受侵害的玉米或高粱与糖蜜草组合,与仅未受侵害的寄主植物相比,组合后的挥发物并没有更具吸引力。单独的受侵害玉米与与糖蜜草组合时一样有吸引力。受侵害高粱比其与糖蜜草的组合更受青睐。糖蜜草的当地生长条件影响对寄生蜂的吸引力。来自锡卡糖蜜草的挥发物有吸引力,而来自姆比塔糖蜜草的挥发物则没有吸引力。在姆比塔种植锡卡糖蜜草使其失去吸引力,反之亦然,姆比塔糖蜜草也是如此。这是由于环境因素同一基因型表现出不同表型的一个例子。