Abstract The expression of aggression in Megaloptera has received little attention, specifically for the adults of the subfamily Corydalinae. Among the New World species of Corydalinae, it is not known if aggression is triggered and expressed in the same way. Since two genera, Corydalus Latreille, 1802 and Platyneuromus Weele, 1909 have different courtship strategies, the effect of the social environment in the expression of aggression in two species of those genera, Corydalus magnus Contreras-Ramos, 1998 and Platyneuromus soror (Hagen, 1861), is examined here and compared with the known data in Corydalus bidenticulatus Contreras-Ramos, 1998. Our results suggest that the triggering of aggressive behaviours in the three species is similar. The decision of whether or not to fight is affected by their social environment: a male is aggressive against other males only when a female is present. Furthermore, the intensity of aggression does not differ among the three species. The behavioural observations support the idea that the mandibles of Corydalus males are used as weapons in male-male competition and during the courtship, but the post-ocular flanges of P. soror males are not involved in male-male competition (they use their short mandibles to bite). Conversely, data show that such a feature might act as a signal trait for female choice.

中文翻译：

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Dobsonflies Corydalus magnus Contreras-Ramos, 1998 和 Platyneuromus soror (Hagen, 1861) (Megaloptera: Corydalidae) 中的攻击性表达

摘要 Megaloptera 的攻击性表达很少受到关注，特别是对于 Corydalinae 亚科的成虫。在 Corydalinae 的新世界物种中，不知道攻击是否以相同的方式被触发和表达。由于两个属，Corydalus Latreille, 1802 和 Platyneuromus Weele, 1909 有不同的求偶策略，社会环境对这些属的两个物种攻击性表达的影响，Corydalus magnus Contreras-Ramos，1998 和 Platyneuromus sor (Hagen, )，在这里进行了检查，并与 Corydalus bidenticulatus Contreras-Ramos, 1998 中的已知数据进行了比较。我们的结果表明，这三个物种对攻击行为的触发是相似的。是否打架的决定受其社会环境的影响：只有当女性在场时，男性才会对其他男性具有攻击性。此外，攻击的强度在三个物种之间没有差异。行为观察支持这样的观点，即 Corydalus 雄性的下颌骨被用作雄性竞争和求爱期间的武器，但 P. soror 雄性的眼后法兰不参与雄性竞争（它们使用短下颌咬合）。相反，数据表明，这样的特征可能是女性选择的信号特征。soror 雄性不参与雄性竞争（它们使用短下颌进行咬合）。相反，数据表明，这样的特征可能是女性选择的信号特征。soror 雄性不参与雄性竞争（它们使用短下颌进行咬合）。相反，数据表明，这样的特征可能是女性选择的信号特征。