Sperm removal behaviour (SRB) is known in many animals, and male genital structures are often involved in the SRB, e.g. rubbing female genitalia vigorously. However, it remains unclear how those male genital structures function properly without severe genital damage during SRB. In the present study, we focused on the bushcricket Metaplastes ornatus and examined the biomechanics of male and female genital structures, involved in their SRB as a model case. During an initial phase of mating, males of this species thrust their subgenital plate with hook-like spurs and many microscopic spines into the female genital chamber. By moving the subgenital plate back-and-forth, males stimulate females, and this stimulation induces the ejection of sperm previously stored in females. We aimed to uncover the mechanics of the interaction between the subgenital plate and genital chamber during SRB. The genital morphology and its material composition were investigated using modern imaging and microscopy techniques. The obtained results showed a pronounced material heterogeneity in the subgenital plate and the genital chamber. The material heterogeneity was completely absent in that of a second bushcricket species, Poecilimon veluchianus, which does not exhibit SRB. Finite element simulations showed that the specific material heterogeneity can redistribute the stress in the subgenital plate of M. ornatus and, thereby, reduces stress concentration during SRB. This may explain why only a few examined males had a broken spur. We suggest that the observed structural features and material heterogeneity in M. ornatus are adaptations to their SRB.

精子去除行为（SRB）在许多动物中是已知的，并且男性生殖器结构经常参与SRB，例如大力摩擦女性生殖器。然而，目前尚不清楚那些男性生殖器结构在SRB期间如何正常运作而不会造成严重的生殖器损害。在当前的研究中，我们集中于丛林criMetaplastes ornatus并考察了男性和女性生殖器结构的生物力学，并以它们的SRB为例。在交配的最初阶段，该物种的雄性用钩状刺刺和许多细刺刺入雌性下生殖板。通过来回移动下生殖器板，雄性刺激雌性，并且这种刺激引起先前储存在雌性中的精子射出。我们旨在揭示SRB期间下生殖器板与生殖器腔之间相互作用的机制。使用现代成像和显微镜技术研究了生殖器形态及其物质组成。获得的结果表明，在生殖器下板和生殖器室中存在明显的物质异质性。Poecilimon veluchianus，不表现出SRB。表明，特定材料的异质性可以重新分布的生殖板的应力的有限元模拟M.奥玛特斯和，由此，SRB过程中减小应力集中。这可以解释为什么只有少数接受检查的雄性马刺破裂。我们建议观察到的结构特征和材料异质性在它们的M. ornatus是对其SRB的适应。