Female predatory response to conspecific males and heterospecific prey in the praying mantis Mantis religiosa: evidence for discrimination of conspecific males

Abstract

Sexual cannibalism, the attack and consumption of the opposite sex by a conspecific during courtship, copulation, or soon after copulation, is widespread among invertebrates, but the causes of this behavior are not fully understood. We examine the mistaken identity hypothesis, which posits that non-copulatory cannibalism occurs because females do not recognize conspecific males as potential mates. This hypothesis predicts indiscriminate predatory behavior by females towards conspecific males and heterospecific prey. This prediction remains largely unexamined. We tested this prediction in the praying mantis Mantis religiosa (Mantodea: Mantidae) through two behavioral experiments. In experiment 1, we presented targets in isolation to females: dead conspecific males or dead common prey items from the field (grasshopper Chrysochraon dispar). In experiment 2, we presented simultaneous live targets to females: conspecific males and grasshoppers. In both experiments, we varied female mating status (virgin vs. mated). Results indicate some degree of attack discrimination by the females. In experiment 1, the females were significantly more likely to strike at the grasshoppers, and showed a shorter latency to strike at grasshoppers. In experiment 2, females tended to preferentially strike at the grasshoppers, although this result fell short of statistical significance. Female discrimination between the males and grasshoppers may be explained, in part, by the size difference between the males and grasshoppers. Female mating status did not affect the occurrence or latency to strike in either experiment. These results fail to strongly support the prediction of indiscriminate predatory behavior by females, while contributing to a broader taxonomic assessment of the mistaken identity hypothesis.