One explanation of the evolution of sexual cannibalism -- the female's consumption of a male during or following courtship or copulation -- is that the male reaps a reproductive benefit by being cannibalized. One route to this reproductive benefit lies in the male's soma increasing his cannibalistic mate's reproductive output. Mating trials (n=38) were performed with the sexually cannibalistic mantid I. oratoria to test the idea that a single meal significantly increases female reproductive output. All females were abundantly fed as virgin, young adults and then starved for 6-8 days before being paired with males. Seven of 38 females cannibalized the males; an additional nine females were fed a cricket nymph after copulation to augment the number of females that fed in the trials. A female's consumption of a meal in the mating trial failed to significantly influence three measures of reproductive output (i.e., the occurrence of oviposition, the mass of the first ootheca, and the number of eggs in the first ootheca), although possible effects of feeding on subsequent ootheca cannot be ruled out. If, however, a single meal provides a negligible benefit to female reproductive output, then the evolution of sexual cannibalism might exist in alternative explanations, such as possible paternity benefits to cannibalized males or cannibalism as a "developmental by-product" of selective pressures on the behavior of nymphs.
Species 1: Mantodea Mantidae Iris oratoria
Keywords: mating behavior, sexual cannibalism
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA