Allochronic isolation can be a strong mechanism for reproductive isolation and speciation. However, imperfect allochrony and the expression of phenological plasticity can erode temporal barriers to gene flow and result in hybridization between divergent lineages. Here, we combine behavioural ecology and genomics to investigate this scenario in two closely related species of grigs in the genus Cyphoderris. These species exhibit a unique mating system whereby females feed on the fleshy hind wings of the male during copulation, and copulation with conspecific males is more likely in food-restricted females than in well-fed females. In western Canada, Cyphoderris buckelli and Cyphoderris monstrosa are sympatric but largely allochronically separated, with C. buckelli breeding earlier. However, their breeding seasons can overlap, leading to potential for older C. buckelli females to mate with young C. monstrosa males to obtain resources via sexual cannibalism. We used behavioural assays to test whether female feeding status affects the propensity for interspecific mating between C. buckelli females and C. monstrosa males. We then tested for hybridization and gene exchange in wild populations of both species, using morphology, mitochondrial DNA and genome-wide nuclear markers. We found that interspecific courtship and mating can occur, but the relationship between food restriction and increased propensity for hybridization was not significant. Although we observed intraspecific population genetic structure in both species, we found no signatures of hybridization in the morphological or genetic datasets, which suggests that postmating reproductive barriers might be preventing successful hybridization in the wild.

中文翻译：

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饥饿会导致一种食人性昆虫（直翅目：Prophalangopsidae）的杂交吗？

等时隔离可以是生殖隔离和物种形成的强大机制。但是，不完美的同时性和物候可塑性的表达可以侵蚀基因流动的时间障碍，并导致不同谱系之间的杂交。在这里，我们结合行为生态学和基因组学，对拟南芥属中两个紧密相关的物种进行了研究。这些物种表现出独特的交配系统，雌性在交配过程中以雄性多肉的后翅为食，在饮食受限的雌性中，与同种雄性交配的可能性比饲喂雌性的雌性高。在加拿大西部，Cyphoderris buckelli和Cyphoderris monstrosa是同胞的，但大部分在时间上是分开的，C. buckelli繁殖较早。然而，它们的繁殖季节可以重叠，导致潜在的老年C. buckelli女性与年轻的队友C. monstrosa男性性通过自相残杀来获得资源。我们使用行为分析来测试女性输送状况是否会影响种间交配的倾向C. buckelli女性和C. monstrosa男性。然后，我们使用形态学，线粒体DNA和全基因组核标记物，对两种物种的野生种群中的杂交和基因交换进行了测试。我们发现种间求偶和交配可能发生，但食物限制与杂交倾向增加之间的关系并不明显。尽管我们在两个物种中都观察到种内种群遗传结构，但我们在形态或遗传数据集中没有发现杂交的迹象，这表明繁殖障碍过后可能会阻止在野生环境中成功杂交。