Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA.
USDA-ARS Southern Insect Management Research Unit, 141 Experiment Station Rd., P.O. Box 346, Stoneville, MS 38776, USA.
Environ Entomol. 2021 Aug 12;50(4):940-947. doi: 10.1093/ee/nvab035.
Wheat stem sawfly, [Cephus cinctus (Hymenoptera: Cephidae)], females display complex behaviors for host selection and oviposition. Susceptible hollow stem wheat (Triticum aestivum L.) cultivars release a greater amount of attractive compound, (Z)-3-hexenyl acetate and receive a greater number of eggs compared to resistant solid stem wheat cultivars. However, barley (Hordeum vulgare L.) is becoming a more common host for C. cinctus in Montana. Therefore, how do host selection and oviposition behaviors on barley cultivars compare to what happens when encountering wheat cultivars? To answer this question, we carried out greenhouse experiments using two barley cultivars: 'Hockett' and 'Craft'. Between these cultivars at Zadoks stages 34 and 49, we compared host selection decisions using a Y-tube olfactometer, compared oviposition behaviors on stems, and counted the number of eggs inside individual stems. In Y-tube bioassays, we found a greater number of C. cinctus females were attracted to the airstream passing over 'Hockett' than 'Craft' barley cultivars. Although the frequencies of oviposition behaviors were similar between these cultivars, the number of eggs was greater in 'Hockett'. Volatile profiles indicated that the amount of linalool was greater in the airstream from 'Craft' than in 'Hockett' at Zadoks 34 while the amount of (Z)-3-hexenyl acetate was greater in airstream from 'Hockett' at both Zadoks 34 and 49. These results suggest that volatiles of barley plants influenced host selection behavior of ovipositing C. cinctus females, while other discriminating behaviors do not differ between cultivars.
小麦茎蜂，[麦茎蜂属（膜翅目：茎蜂科）]，雌性在宿主选择和产卵时表现出复杂的行为。易感空心茎小麦（Triticum aestivum L.）品种释放出更多有吸引力的化合物（Z）-3-己烯基乙酸酯，并且比抗性实心茎小麦品种接收更多的卵。然而，大麦（Hordeum vulgare L.）在蒙大拿州正成为 C. cinctus 的一个更常见的宿主。因此，在大麦品种上的宿主选择和产卵行为与遇到小麦品种时有何不同？为了回答这个问题，我们在温室中使用两个大麦品种：“霍基特”和“克拉夫特”进行了实验。在这两个品种的 Zadoks 阶段 34 和 49 之间，我们使用 Y 形嗅觉仪比较了对宿主的选择决策，比较了茎上的产卵行为，并计算了每个茎内的卵数。在 Y 形生物测定中，我们发现更多的 C. cinctus 雌性被吸引到经过“霍基特”大麦品种而不是“克拉夫特”大麦品种的气流中。尽管这些品种的产卵行为频率相似，但“霍基特”的卵数更多。挥发物谱表明，在 Zadoks 34 时，“克拉夫特”气流中的里哪醇含量大于“霍基特”，而在 Zadoks 34 和 49 时，“霍基特”气流中的（Z）-3-己烯基乙酸酯含量大于“克拉夫特”。这些结果表明，大麦植株的挥发物影响了产卵的 C. cinctus 雌性的宿主选择行为，而品种之间的其他辨别行为没有差异。
