Observations on the mating behavior of a South American species of the genus Corydalus (Megaloptera: Corydalidae)

The genus Corydalus is endemic to North and South America and displays sexual dimorphism, with males having much larger mandibles than females, in some species.  Unlike other insect orders with similar sexual dimorphism, behaviors associated with the enlarged male mandibles of Corydalus are not well documented in the literature.  Male-male and male-female interactions were observed at a light trap in Culebrayoc, Peru.  Males used their enlarged mandibles in both physical and non-physical male-male aggressive interactions as well as apparent courtship behaviors.  Males with the larger mandibles did not always win male-male interactions, suggesting that mandible size may not be the ultimate factor in determining the winner of male-male competition.  Courtship behaviors matched previous observations, though a novel behavior of males using their mandibles to lift the wings of females before copulation was observed.  These observations add to the knowledge of both Corydalus mating behavior and behaviors associated with enlarged male mandibles.