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

洲际传播与寄主植物-食草动物相互作用之间的关系尚不清楚，但可能为入侵物种的相互作用提供见解。两种狗毒叶甲虫（金花科，金花科）具有适应性，使它们能够以北美有毒的狗毒植物（罗布麻，罗布麻科）为食。与罗布麻一起生活在亚洲的有八种金蝇，但它们在那里的相互作用的性质，以及它们在北美是何时以及如何进化的，都是未知的。本项目将研究金花菊与夹竹桃科植物的亲缘关系演变，重点研究广泛分布的金花菊与其多寄主之间的相互作用。将在中国收集黄蝇属及其寄主植物的标本，以确定以前未知的寄主关联并建立进化树。将对中华绒螯蟹进行摄食实验，以确定不同的种群是否会吃不同的宿主，这通常是物种形成的早期步骤。实验将由北京动物研究所（IOZ）副教授、昆虫寄主植物专业化进化专家薛怀军博士指导。IOZ位于几个金曲科物种的范围内，拥有亚洲最大的金曲科甲虫收藏，使其成为研究其进化的理想地点。该奖金将用于在中国5个省收集10个金喉和桔喉（一个密切相关的属）物种的标本。收集寄主植物、夹竹桃科其他植物的摄食行为。这项工作将扩大该类群的寄主关联信息，随后将利用高通量Illumina测序技术对野外采集和博物馆标本中的DNA进行测序，以构建第一个具有完整物种样本的黄蝇分子系统发育。在北京采集中华月夜蛾的个体，在几种潜在寄主植物上取食，进行寄主接受和产卵实验。它们对潜在寄主的偏好和适应性将通过诸如生长和产卵率等代理来评估，以确定是否有证据表明寄主种族的进化。该项目将有助于植物-昆虫相互作用领域，一个未被充分研究的生物群体的自然史，并鼓励德雷塞尔大学自然科学院与IOZ之间的未来合作。该奖项隶属于东亚和太平洋暑期研究所项目，由美国国家科学基金会和中国科技部共同资助，支持美国研究生的暑期研究。

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.