In many species of spiders and praying mantids females attack and kill males during, after, or even before copulation. Sexual cannibalism thus constitutes often an extreme form of sexual conflict (unless males sacrifice themselves). Females may attack and kill males in the context of mating because a) they benefit from the energy and nutrient intake by eating the male (adaptive foraging hypothesis), they are selected to be very aggressive foragers and attack the male by accident (mal-adaptive aggression spill-over hypothesis), c) they discriminate among males to select the best sire of their offspring (mate choice hypothesis), d) they try to prevent males from monopolization the fertilization of the eggs (genetic diversity hypothesis), or any combination of these factors as the various hypotheses are not mutually exclusive. New data suggests that the repeated evolution of pronounced sexual size dimorphism may have set the stage for the evolution of sexual cannibalism in various spider lineages, but the underlying female motivation to cannibalize males probably differs among species. For current and past projects see Publications and People.

Please click on the images below to watch mating in Argiope aurantia. The first clip (top) shows three sequences involving three different mating pairs (all individuals are intially virgin). The second clip shows a male's second insertion (i.e. one palp was already used); he dies sponaneously in copula and is pulled out by the female (see Mating Systems). Note that with the exception of the first sequence of the first video, females always attack the male by throwing silk threads over him while mating.