PDF(Pubmed)
Abstract：
Understanding the often antagonistic plant-herbivore interactions and how host defenses can influence herbivore dietary breadth is an area of ongoing study in ecology and evolutionary biology. Typically, host plants/fungi that produce highly noxious chemical defenses are only fed on by specialists. We know very little about generalist species that can feed and develop on a noxious host. One such example of generalists feeding on toxic host occurs in the mushroom-feeding Drosophila found in the immigrans-tripunctata radiation. Although these species are classified as generalists, their acceptable hosts include deadly Amanita species. In this study, we used behavioral assays to assess associations between one mushroom-feeding species, Drosophila guttifera, and the deadly Amanita phalloides. We conducted feeding assays to confirm the presence of cyclopeptide toxin tolerance. We then completed host preference assays in female flies and larvae and did not find a preference for toxic mushrooms in either. Finally, we assessed the effect of competition on oviposition preference. We found that the presence of a competitor\'s eggs on the preferred host was associated with the flies increasing the number of eggs laid on the toxic mushrooms. Our results highlight how access to a low competition host resource may help to maintain associations between a generalist species and a highly toxic host.
摘要：
了解经常拮抗的植物-草食动物相互作用以及宿主防御如何影响草食动物的饮食广度是生态学和进化生物学正在进行的研究领域。通常,产生高度有害化学防御的寄主植物/真菌仅由专家喂养。我们对可以在有害宿主上觅食和发育的通才物种知之甚少。以有毒宿主为食的通才的一个例子发生在以蘑菇为食的果蝇中。尽管这些物种被归类为通才，它们可接受的寄主包括致命的天牛物种。在这项研究中,我们使用行为分析来评估一种以蘑菇为食的物种之间的关联，果蝇，和致命的天鹅膏。我们进行了喂养测定以确认环肽毒素耐受性的存在。然后，我们完成了对雌性苍蝇和幼虫的宿主偏好测定，并且没有发现对有毒蘑菇的偏好。最后,我们评估了竞争对产卵偏好的影响。我们发现，在首选宿主上存在竞争者的卵与苍蝇增加了有毒蘑菇上产卵的数量有关。我们的结果强调了如何获得低竞争的宿主资源可能有助于维持通才物种与剧毒宿主之间的联系。
