Assassin bugs: evolutionary history of the Reduvioidea, a diverse clade of predatory and hematophagous insects

进化研究探索形成生物多样性的过程。有近7000种已知的科学，刺客虫是最大的动物进化谱系之一，其中大多数物种捕食其他昆虫。导致猎蝽如此大规模形成的因素尚不清楚，但对某些猎物生物的特化和向各种陆地栖息地的过渡被认为是造成这一现象的原因。这些假设在很大程度上仍未得到检验，因为没有全面的进化树。刺客虫包括用于控制植物害虫的有益物种，传粉者掠食者，以及传播恰加斯病病原体的强大的人类疾病媒介。由加州大学河滨分校的研究人员领导的一个国际团队将调查刺客虫的进化史，将广泛的遗传和形态数据与创新方法联系在一起，以收集自然历史数据。一名博士后研究员和一名博士生将接受培训，几名本科生研究人员将从事研究和推广工作，两门关于真正的昆虫生物多样性的短期课程将培训学生、研究人员和其他从事农业和公共卫生相关研究和监测的人员。现有的刺客蝽或Reduvioidea的系统发育不足以解决许多进化问题，缺乏描述良好的化石使得很难建立事件的时间表，包括从掠食性生活方式到吸血生活方式的转变，Reduvioidea的分类也很混乱。该项目将：1)测试系统发育假说，重点关注尚不明确的高等Reduviidae和吸血恰加斯病媒介Triatominae之间有争议的关系，同时最大限度地扩大分类覆盖范围，整合转录组学、锚定杂交富集、传统分子和形态学数据集；2)描述和重新描述化石类生物，以弥合化石记录中的分类和地质空白，并检验关键生物事件发生时间的假设；3)将元条形码方法应用于刺客虫肠道内容，以补充现有的猎物数据；4)研究不同物种的多样性，重点研究物种多样性速率变化的假设和相关关键创新，以及从捕食向吸血过渡的形态、生理和生态特征；5)利用本项目的系统发育信息，提出一种新的Reduvioidea分类。

Evolutionary research explores processes that have shaped biodiversity. With close to 7,000 species known to science, assassin bugs are one of the largest evolutionary lineages of animals where the majority of species hunt other insects. The factors that have allowed assassin bugs to speciate at this scale are unknown, but specializations on certain prey organisms and transitions into a variety of terrestrial habitats are assumed to have contributed to this phenomenon. These hypotheses have largely remained untested, because comprehensive evolutionary trees are unavailable. Assassin bugs include beneficial species used to control plant pests, pollinator predators, and powerful human disease vectors that transmit the causative agent of Chagas disease. An international team led by researchers at the University of California, Riverside will investigate the evolutionary history of assassin bugs, tying together extensive genetic and morphological data with innovative approaches to gather natural history data. One postdoctoral researcher and one PhD student will be trained, several undergraduate researchers will engage in research and outreach, and two short courses on true bug biodiversity will train students, researchers, and others involved in agricultural and public health related research and monitoring. Existing phylogenies of the assassin bugs or Reduvioidea are inadequate to address many evolutionary questions, the paucity of well-described fossils has made it difficult to establish timelines for events including the transition from predatory to blood-feeding life styles, and the classification of Reduvioidea is in disarray. This project will: 1) test phylogenetic hypotheses with emphasis on the poorly resolved Higher Reduviidae and contentious relationships of the hematophagous Chagas disease vectors Triatominae, while maximizing taxonomic coverage and integrating transcriptomic, anchored hybrid enrichment, traditional molecular, and morphological datasets; 2) describe and redescribe fossil reduvioids to bridge taxonomic and geological gaps in the fossil record and test hypotheses on the timing of key biological events; 3) apply metabarcoding approaches to assassin bug gut contents to complement available prey data; 4) study diversification across Reduvioidea, focusing on hypotheses of diversification rate shifts and correlated key innovations, and morphological, physiological, and ecological traits involved in the transition between predation and blood-feeding; 5) use the phylogenetic information generated during this project to propose a new classification of Reduvioidea.