Male genital titillators and the intensity of post-copulatory sexual selection across bushcrickets

Animal genitalia are diverse and a growing body of evidence suggests that they evolve rapidly under post-copulatory sexual selection. This process is predicted to be more intense in polyandrous species, although there have been very few comparative studies of the relationship between the complexity of genital structures in males and measures of the degree of polyandry. In some bushcricket families, males possess sclerotized copulatory structures known as titillators, which are inserted into the female’s genital chamber and moved rhythmically. Like other genital structures, bushcricket titillators are widely used as important taxonomic characters and show considerable variation across species in structure, shape, and the extent to which they are spined. Here, we examine relationships between the presence/absence of titillators, titillator complexity, and both mating frequency and the degree of polyandry in bushcrickets, using phylogenetic comparative analyses. Using published sources com...动物生殖器官多样性丰富，越来越多的研究证据表明，它们在交配后性选择（post-copulatory sexual selection）的作用下快速演化。该演化过程在一妻多夫物种中预计更为强烈，但目前针对雄性生殖结构复杂程度与一妻多夫程度量化指标之间关联的比较研究仍极为匮乏。在部分螽斯科（bushcricket families）类群中，雄性拥有一类被称为交配刺激器（titillators）的骨化交配结构，该结构可插入雌性生殖腔并进行节律性运动。与其他生殖结构类似，螽斯的交配刺激器被广泛用作重要的分类学特征，且在不同物种间展现出结构、形态的显著差异以及棘刺化程度的变化。本研究采用系统发育比较分析方法，探讨了螽斯类群中交配刺激器的有无、复杂程度，与交配频率及一妻多夫程度之间的关联。本研究利用已发表的文献资料……