SG: Understanding the genetic and behavioral basis of novel social phenotypes in damaging invasive wasps

入侵物种可能成为主要的城市害虫，破坏农业，并摧毁入侵地区的本土物种。尽管造成了如此广泛的危害，但入侵者的哪些特征允许他们传播仍然存在许多问题。在入侵物种中，群居昆虫因其群体规模大和合作行为而危害更大。一种特征是能够组成包含多只蚁后的群体，这是几种最具破坏性的入侵群居昆虫的共同特征，包括阿根廷蚂蚁、火蚁和黄夹克黄蜂。结合实验、行为观察和遗传分析，我们的研究询问了入侵的黄蜂为什么以及如何形成多女王群体。这个项目将比较原生种群和入侵种群，前者大多数蜂群只有一只蜂王，持续一年，后者蜂群含有多个蜂王，增长到非常大的规模，可能持续数年。这一系统为研究多女王社会和确定这一战略的优势和劣势提供了一个理想的机会。这项研究还将为控制入侵黄蜂的努力提供参考。这项研究为学生提供了教育机会，并将通过提供影响非本土物种入侵因素的基本信息来造福社会。尽管由非亲属组成的社会存在于许多生物体中，但从简单的以家庭为基础的社会群体向更复杂的社会组织转变的驱动因素仍然是个谜。黄夹克(VesPula spp.)提出一个吸引人的模型系统，因为向多女王、多年生蜂群的转变最近发生了，并且在不同的入侵种群中收敛。这种早期的表型为了解重大进化转变早期阶段的动态过程提供了一个窗口。使用三管齐下的方法，该项目将为重新筛选过程提供新的线索。Requening将入侵范围内发现的多女王、多年生蜂群与在大多数原生范围内出现的单一女王、一年生蜂群区分开来。首先，在野外试验中，交配后的蜂王将被试验性地引入蜂群入口处，以直接测试来自本地和入侵种群的蜂王和工蚁的行为反应和基因表达谱。如果多蜂王蜂群中的工蚁更有可能接受新的蜂王，那么与单蜂王蜂群的工蚁相比，他们对引入的蜂王的攻击性应该会减少。同时，在单蜂群和多蜂群引入蜂王的过程中，已知的调节其他昆虫攻击性的基因应该在工蜂和蜂王的大脑中差异表达。这两个社会背景之间的其他监管差异将被确定。其次，将在入侵生境中连续调查蜂群的遗传结构，以确定在种群生命周期中何时发生再繁殖，共生蜂王之间的亲缘关系，并估计建立和加入蜂王的寿命。最后，将通过对数百只年龄匹配的幼崽进行基因分型来评估多皇后、一夫多妻制群体中的生殖分割。了解蜂王数量、蜂王寿命和生殖分割之间的相互作用，将为我们提供新的见解，以了解介导这一重大进化转变的选择性力量，以及在这个系统中，有害的入侵表型。

Invasive species can become major urban pests, damage agriculture, and devastate native species in invaded areas. Despite such widespread harm, many questions remain about what characteristics of invaders allow them to spread. Among invasive species, social insects are more harmful due to their large colony sizes and cooperative behaviors. One trait, the ability to form groups containing multiple queens, is shared by several of the most devastating invasive social insects, including Argentine ants, fire ants, and yellowjacket wasps. Combining an experiment, behavioral observations, and genetic analyses, our research asks why and how invasive yellowjacket wasps form multi-queen colonies. This project will compare native populations, where most colonies have a single queen and persist for one year, to invasive populations, where colonies contain multiple queens, grow to very large sizes, and may persist for several years. This system provides an ideal opportunity to study multi-queen societies and to identify strengths and weaknesses of this strategy. This research will also inform efforts to control invasive wasps. The research supports educational opportunities for students and will benefit society by providing basic information on the factors influencing invasiveness of non-native species.Although societies composed of non-relatives occur in many organisms, the drivers of the transition from simple family-based social groups to more complex social organization remain enigmatic. Yellowjackets (Vespula spp.) present a fascinating model system because the transition to multi-queen, perennial colonies has occurred recently and convergently in different invasive populations. This incipient phenotype offers a window into the dynamic processes underlying early stages of a major evolutionary transition. Using a three-pronged approach, this project will shed new light on the requeening process. Requeening distinguishes the multi-queen, perennial colonies found in the invasive range from the single-queen, annual colonies that occur in most of the native range. First, in field trials, mated queens will be experimentally introduced to colony entrances to directly test the behavioral response and gene expression profiles of queens and workers from both native and invasive populations. If workers in multi-queen colonies are more likely to accept new queens, they should display decreased aggression toward introduced queens compared to workers from single-queen colonies. In parallel, genes known to mediate aggression in other insects should be differentially expressed in the brains of workers and queens during queen introduction in the single- versus multi-queen colonies. Additional regulatory differences between these two social contexts will be identified. Second, the genetic structure of colonies will be surveyed successively in the invasive habitat to determine when in the colony life cycle requeening occurs, relatedness among co-occurring queens, and to estimate the longevity of founding and joining queens. Finally, reproductive partitioning in multi-queen, polygynous colonies will be assessed by genotyping hundreds of age-matched brood. Understanding the interactions between colony queen number, queen longevity and reproductive partitioning will provide novel insights into the selective forces that mediate this major evolutionary transition and, in this system, a harmful invasive phenotype.