COLLABORATIVE RESEARCH: Multimodal signaling in rhinoceros beetles

这项研究旨在通过关注动物武器和求偶展示来了解生物多样性，这些特征往往比其他特征更快地多样化。雄性犀牛甲虫头上挥舞着一个巨大的，干草叉状的角，它们用来在竞争对手之间争夺雌性的觅食领地。角最长的雄性获胜，部分原因是角的长度准确地反映了雄性的体型和战斗能力-这是雄性质量的真实信号。然而，调查人员先前的工作显示，赢得战斗是不够的。即使在争夺领地之后，雄性仍然必须每天晚上花几个小时用翅膀上的一种新文件对雌性“唱歌”，它们摩擦腹部的一个盘子，它们在蜡质的外角质层中产生混合气味，似乎传达雄性的体型和营养状况。这项研究将探讨男性状况与歌曲和气味信号之间的联系，研究女性对这些信号的偏好，并描述这套求偶信号在物种范围内的多样化。女性如何区分男性，为什么她们忽视了男性品质的明显信号（角）？调查人员还将与舞蹈贡扎加系合作，设计受动物行为启发的表演，为米苏拉昆虫馆开发昆虫歌曲互动展览，并通过丹佛大学为K-16学生设计互动在线课程，与公众分享有关甲虫的信息。 之前对日本犀牛甲虫Trypoxylus dichotomus的研究，一种以教科书资源防御交配系统为特征的重型武器物种，导致研究人员怀疑这些甲虫显示出lekking行为的元素。雌性不愿意与守卫觅食领地的常驻雄性交配，尽管这些雄性一直是种群中最大、角最长的个体。使用实验室操作实验和现场观察和扰动相结合，本研究将严格的特征在犀牛甲虫（目标1）的鸣叫和表皮碳氢化合物（CHC）配置文件信号，并评估其重要性，女性择偶（目标2）和男性竞争对手的评估在比赛中（目标3）。此外，本研究将比较歌曲方言和CHC配置文件在整个范围内的这个物种（目标4），以对比进化的相对速率的竞争和择偶信号。最后，他们将对相邻的、遗传相似但表型不同的群体进行数量性状基因座作图研究，将所得的连锁图谱与重新测序的参考基因组结合起来，并将先前对相同群体进行的PoolSeq研究的FST“离群值”结果结合起来，该奖项反映了NSF的法定使命，并被认为是值得的。通过使用基金会的知识价值和更广泛的影响审查标准进行评估来提供支持。

This study seeks to understand biodiversity by focusing on animal weapons and courtship displays, which often diversify more rapidly than other traits. Male rhinoceros beetles wield a giant, pitchfork-shaped horn on their head that they use in battles between rival males over feeding territories visited by females. Males with the longest horns win, in part because horn length accurately reflects body size and fighting ability of males - it is an honest signal of male quality. Prior work by the investigators revealed that winning fights is not enough, however. Even after battling to hold a territory, males must still spend hours each night "singing" to females using a novel file on their wing covers that they rub against a plate on their abdomen, and they produce blends of scents in their waxy outer cuticle that appear to communicate male body size and nutritional state. This study will explore the link between male condition and both song and scent signals, examine female preferences for these signals, and characterize the diversification of this suite of courtship signals across the range of the species. How do females discriminate among males, and why do they ignore the obvious signal of male quality (the horn)? The investigators will also work with the Gonzaga department of dance to design performances inspired by animal behavior, develop an interactive exhibit on insect songs for the Missoula Insectarium, and design interactive online curricula for K-16 students through the University of Denver to share information about beetles with the public. Prior work on the Japanese rhinoceros beetle, Trypoxylus dichotomus, a heavily weaponed species characterized by a textbook resource defense mating system, led the investigators to suspect that these beetles show elements of lekking behavior. Females are reluctant to mate with resident males guarding feeding territories despite those males consistently being among the largest, longest-horned individuals in the population. Using a combination of laboratory manipulation experiments and field observation and perturbations, this study will rigorously characterize stridulatory song and cuticular hydrocarbon (CHC) profile signals in rhinoceros beetles (Aim 1), and evaluate their importance to female mate choice (Aim 2) and male rival assessment during contests (Aim 3). In addition, this study will compare song dialects and CHC profiles across the range of this species (Aim 4), to contrast the relative rates of evolution of agonistic and mate-choice signals. Finally, they will perform a quantitative trait locus mapping study of adjacent, genetically similar but phenotypically divergent populations, combining the resulting linkage maps with a re-sequenced reference genome, and FST 'outlier' results from a prior PoolSeq study of the same populations, to delve into the genetic architecture of this suite of multimodal signal traits.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.