Local population density and group composition influence signal-preference relationships in Enchenopa treehoppers (Hemiptera: Membracidae)

Many animals exhibit social plasticity—changes in phenotype or behavior in response to experience with conspecifics—that change how evolutionary processes like sexual selection play out. Here, we asked whether social plasticity arising from variation in local population density in male advertisement signals and female mate preferences influences the form of sexual selection. We manipulated local density and determined whether this changed how the distribution of male signals overlapped with female preferences—i.e., the signal-mate preference relationship. We specifically look at the shape of female mate preference functions, which, when compared to signal distributions, provide hypotheses about the form of sexual selection. We used Enchenopa binotata treehoppers, a group of plant feeding insects that exhibit natural variation in local densities across individual host plants, populations, species, and years. We measured male signal frequency and female preference functions across the den...诸多动物均表现出社会可塑性（social plasticity）——即因与同种个体的互动经历而改变自身表型或行为——这一过程会改变性选择等进化进程的运作模式。本研究旨在探究：由雄性求偶信号与雌性配偶偏好的局域种群密度差异所引发的社会可塑性，是否会对性选择的形式产生影响。我们通过实验操控局域种群密度，并以此检验该操作是否会改变雄性信号分布与雌性配偶偏好的匹配程度——即信号-配偶偏好关联模式。我们重点关注雌性配偶偏好函数的形态，将其与雄性信号分布对比后，可推导得出关于性选择形式的相关假说。本研究选用双斑恩角蝉（Enchenopa binotata treehoppers）作为实验对象，这类植食性昆虫在单株寄主植物、种群、物种乃至不同年份间，其局域种群密度均存在自然差异。我们在不同密度条件下测定了雄性信号频率与雌性配偶偏好函数……