EAPSI: Plant-herbivore Interactions and Host Race Formation: Reconstructing the Evolution of Chrysochus-Apocynaceae Associations

洲际扩散和寄主植物-食草动物相互作用的进化之间的关系还没有被很好地理解，但可以提供对入侵物种惰性行为的洞察。两种罗布麻叶甲虫(叶甲科、金甲科)具有适应能力，可以捕食北美有毒的罗布麻属植物(罗布麻科、罗布麻科)。有八种金鱼与罗布麻属一起生活在亚洲，但它们在那里相互作用的性质，以及这种联系在北美是何时和如何演变的，尚不清楚。本项目将研究金丝桃科和罗布麻科之间的联系的进化，重点是广泛分布的中华绒毛虫与其多个寄主之间的相互作用。中国将采集金丝菊及其寄主植物的标本，以鉴定以前未知的寄主联想，并创建进化树。将在中华绒毛虫上进行摄食实验，以确定不同的种群是否吃不同的寄主，这通常是物种形成的早期步骤。实验将由北京动物研究所副教授、昆虫-寄主植物专门化进化专家薛怀军博士指导。位于几个金龟子物种的范围内，IOZ拥有亚洲最大的甲虫收藏，使其成为研究它们进化的理想地点。该奖项将用于在中国的五个省收集十个金龟子和扁角金龟子(一个密切相关的属)的标本。将在这些地区收集寄主植物、罗布麻科其他植物以及对取食行为的观察。这项工作将扩展该群的寄主关联信息，并将利用高通量Illumina测序对现场采集的和博物馆标本中的DNA进行测序，以构建第一个具有完整物种样本的金龟属的分子系统学。在寄主接受和产卵实验中，将在北京采集中华绒毛虫个体，并取食几种潜在的寄主植物。它们对潜在寄主的偏好和适合度将通过生长和产卵率等指标进行评估，以确定是否有证据表明寄主种族的进化。该项目将在植物-昆虫相互作用领域做出贡献，研究一组未被充分研究的生物的自然历史，并鼓励德雷克塞尔大学自然科学院和IOZ之间未来的合作。东亚和太平洋夏季学院计划下的这个奖项支持一名美国研究生的夏季研究，由NSF和中国科技部联合资助。

The relationships between intercontinental dispersals and the evolution of host plant-herbivore interactions are not well understood, but may offer insight into invasive species ineractions. Two species of dogbane leaf beetles (Chrysochus, Chrysomelidae) possess an adaptation allowing them to feed on the toxic dogbane plants (Apocynum, Apocynaceae) in North America. Eight Chrysochus species live in Asia alongside Apocynum, but the nature of their interactions there, and when and how the association in North America evolved, is unknown. This project will investigate the evolution of the association between Chrysochus and Apocynaceae, focusing on the interactions between the widespread C. chinensis and its multiple hosts. Specimens of Chrysochus and their host plants will be collected in China to identify previously unknown host associations and create an evolutionary tree. Feeding experiments will be conducted on C. chinensis to determine whether separate populations eat different hosts, often an early step toward speciation. Experiments will be supervised by Dr. Huai-Jun Xue, associate professor at the Institute of Zoology (IOZ) in Beijing and expert on the evolution of insect-host plant specialization. Situated within the ranges of several Chrysochus species, the IOZ holds the largest collection of the beetles in Asia, making it the ideal location to investigate their evolution.The award will be used to collect specimens of ten Chrysochus and Platycorynus (a closely related genus) species in five provinces in China. Host plants, other plants in the Apocynaceae, and observations of feeding behavior will be collected in those areas. This work will expand the host association information for the group, and DNA from field-collected and museum specimens will later be sequenced with high-throughput Illumina sequencing to construct the first molecular phylogeny of Chrysochus with complete sampling of species. C. chinensis individuals will be collected in Beijing and fed on several potential host plants in host acceptance and oviposition experiments. Their preference for, and fitness on, the potential hosts will be assessed by proxies such as growth and oviposition rates to determine whether there is evidence for the evolution of host races. This project will contribute to the field of plant-insect interactions, the natural history of an understudied group of organisms, and encourage future cooperation between the Academy of Natural Sciences of Drexel University and the IOZ.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Chinese Ministry of Science and Technology.