International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.
Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa.
Sci Rep. 2019 Mar 7;9(1):3850. doi: 10.1038/s41598-019-40479-9.
Selection of oviposition substrate is critical in holometabolous insects. Female stable flies, Stomoxys calcitrans, locate and select vertebrate herbivore dung in which they lay their eggs. However, the preference for vertebrate herbivore dung by S. calcitrans females, its fitness consequences for offspring, and the semiochemicals used to locate and select oviposition substrates remain unclear. Using oviposition choice tests and life table bioassays we found that gravid female S. calcitrans prefer to oviposit on donkey and sheep dung, which also improves the performance of their offspring. GC-MS analysis followed by random forest classification identified β-citronellene and carvone as the most important predictive volatile organic compounds of donkey and sheep dung, respectively. In multiple choice oviposition bioassays, S. calcitrans laid more eggs in wet sand containing β-citronellene and carvone than in other treatments. The attractiveness of these compounds was confirmed in a field trial, with traps baited with β-citronellene and carvone catching more S. calcitrans. We conclude that gravid female S. calcitrans use semiochemical cues to choose oviposition substrates that maximise offspring fitness.
产卵基质的选择对完全变态昆虫至关重要。厩螫蝇（Stomoxys calcitrans）雌性通过定位和选择脊椎动物草食动物的粪便来产卵。然而，厩螫蝇雌性对脊椎动物草食动物粪便的偏好、其对后代的适应度后果，以及用于定位和选择产卵基质的信息素仍然不清楚。通过产卵选择试验和生命表生物测定，我们发现怀孕的厩螫蝇雌性更喜欢在驴和羊的粪便上产卵，这也提高了后代的表现。GC-MS 分析结合随机森林分类确定了 β-香茅烯和香芹酮分别是驴和羊粪便最重要的预测性挥发性有机化合物。在多项选择产卵生物测定中，厩螫蝇在含有 β-香茅烯和香芹酮的湿沙中产卵多于其他处理。在田间试验中证实了这些化合物的吸引力，用 β-香茅烯和香芹酮诱饵的诱捕器捕获了更多的厩螫蝇。我们得出结论，怀孕的厩螫蝇雌性使用信息素来选择最大化后代适应性的产卵基质。
