Sexual Cannibalism in the Praying Mantis Hierodula Membranacea

We tested the idea that sexual cannibalism increases male and female fecundity in the mantid Hierodula membranacea. Two experiments were performed, in the first we maintained females on one of three nutritional planes; high medium or low. Food intake was positively and significantly associated with: maximum mass attained, the mass of first and subsequent oothecae, and the rate at which oothecae were produced. Ootheca mass was positively correlated with maximum female mass, and the number of young hatching from oothecae was positively correlated with ootheca mass. In the second experiment we maintained females on low diets and allowed some to eat the male during mating and prevented others from doing so. Females which ate the male produced significantly heavier oothecae than those which did not. The female's nutritional state influenced her likelihood of eating the male; well fed females rarely ate males. These results confirm that under certain food regimes male and female fecundity are increased by sexual cannibalism. However, our observations indicate that males do not sacrifice themselves at mating, but attempt to avoid being eaten, suggesting that while sexual cannibalism may be adaptive for females it is unlikely to be so for male H. membranacea.