Asymmetric reproductive interference between specialist and generalist predatory ladybirds
Asymmetric reproductive interference between specialist and generalist predatory ladybirds
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专科和通才掠食性瓢虫之间的不对称生殖干扰
DOI：
10.1111/j.1365-2656.2012.01984.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Naoya Osawa & Takayoshi Nishida
中科院分区：
文献类型：
--
作者：
Suzuki Noriyuki;Yuichi Kameda & Naoya Osawa;Naoya Osawa & Takayoshi Nishida
1.近缘物种在所开发资源的质量和广度上往往有很大差异，但造成这些差异的实际机制却鲜为人知。由于在实验室中，专门化物种经常存活下来，并在从未在自然界中利用过的寄主物种上表现得同样好或更好，因此必须存在限制寄主范围的负生态相互作用。在这里，我们把重点放在生殖干扰上，理论上预测这会导致具有重叠交配信号的密切相关物种之间的生态位分离。2.我们研究了两个近亲瓢虫物种间的性行为与生态专门化和泛化的关系。Harmonia yedoenssis和Harmonia axyrisis是一种专门捕食松蚜的专业捕食者，松蚜是瓢虫孵化的高度难以捉摸的猎物，3.我们的实验表明，当同种精子与同种和异种雄性交配时，同种精子与绝大多数卵受精(即同种精子优先)。此外，我们还证明，随着异种密度相对于同种密度的增加，雌蜂的交配机会显著减少。在异种密度下，雌性交配成功率较高。4.我们的结果表明，在生殖干扰方面，通用型对专化型应为显性。我们的结果支持这一假设，即来自优势物种的不对称生殖干扰可能迫使非优势物种成为专门捕食者，专门利用自然界中不太受欢迎的猎物。
1.Closely related species often differ greatly in the quality and breadth of resources exploited, but the actual mechanisms causing these differences are poorly understood. Because in the laboratory specialized species often survive and perform as well or better on host species that are never utilized in nature, negative ecological interactions restricting host range must exist. Here, we focused on reproductive interference, which has been theoretically predicted to drive niche separation between closely related species with overlapping mating signals.2.We examined the interspecific sexual interactions in relation to ecological specialization and generalization in two sibling ladybird species,Harmonia yedoensisandHarmonia axyridis.Harmonia yedoensisis a specialist predator that preys only on pine aphids, which are highly elusive prey for ladybird hatchlings, whereasH. axyridisis a generalist predator with a broad prey and habitat range.3.We experimentally showed that conspecific sperm fertilized the vast majority of eggs regardless of mating order (i.e. conspecific sperm precedence) when a female ofH. yedoensisorH. axyridismated with both a conspecific and a heterospecific male. Moreover, we demonstrated that mating opportunities ofH. yedoensisfemales strongly decreased as heterospecific density increased relative to conspecific density. In contrast, inH. axyridis, female mating success was high regardless of conspecific or heterospecific density.4.Our results suggest that the generalistH. axyridisshould be dominant to the specialistH. yedoensisin terms of reproductive interference. Our results support the hypothesis that asymmetric reproductive interference from the dominant species may force the non‐dominant species to become a specialist predator that exclusively utilizes less preferred prey in nature.