Extra-genital wounding delays remating in the sexually cannibalistic springbok mantis

A fascinating consequence of sexual conflict in animals is the maintenance of traits in males that cause physical damage to females during mating interactions. Such harm is hypothesised to be either an adaptation that enhances male fitness, or a collateral side-effect of adaptations that benefit males in other contexts. Tests of these hypotheses have mostly focused on traumatic copulation, where males wound females internally with weaponised genitalia, despite the widespread occurrence of extra-genital injury inflicted by non-genitalic structures like teeth, fangs or claws. Here, we take advantage of the unique mating interactions of the sexually cannibalistic springbok mantis, Miomantis caffra, to investigate the evolution of extra-genital wounding. Males of this species use their foretibial claws to stab females in the abdomen while fighting back against cannibalistic attacks during mating attempts. If stabbing females is adaptive, we predicted that experimentally wounded females would alter their remating behaviour or reproductive scheduling to the benefit of their mates. We found that injured females did not differ in their attractiveness or remating likelihood compared to intact females, and did not show an enhanced propensity to attack second courting males. Injured females also showed no change in mortality, fecundity, or offspring production that would suggest terminal investment due to male manipulation through wounding. However, our experiments revealed a statistically significant delay in the timing of remating among injured females, which could be interpreted as a benefit to males if such a delay reduces sperm competition. But given that remating was not prevented, only deferred, the injury-induced delay we observed is unlikely to be ecologically important, although field studies would be required to confirm this. Taken together, our results suggest that extra-genital wounding in the springbok mantis is unlikely to be adaptive but may instead be a pleiotropic side-effect of males trying to avoid being cannibalised.