Sexual conflict in a sexually cannibalistic praying mantid: Males prefer low-risk over high-risk females

Abstract

Sexually cannibalistic species such as praying mantids are an ideal model in which to study sexual conflict since the interests of both sexes under a cannibalistic scenario are clearly opposed. Females gain direct material benefits of feeding on a male, which can in turn boost female reproductive output. Males, on the other hand, pay a high cost when cannibalized since they lose all chance of future reproduction. Here, we tested the hypothesis that males behave so as to reduce the risk of being cannibalized in the praying mantid Parastagmatoptera tessellata. Twenty-six males were tested in a choice experiment where two options were presented simultaneously: one aggressive female (signalling high risk of cannibalism) and one nonaggressive female (low risk of cannibalism). We predicted that males would prefer nonaggressive over aggressive females. We found evidence that males are sensitive to the predatory strike of a female towards a conspecific male, showing a strong preference for nonaggressive females based on the time that males spent near each type of female. In addition, the preference index we used was a predictor of mating attempts. We therefore conclude that males' behaviour is adaptive, as it serves to reduce their probability of being cannibalized by females.