The risk of sexual cannibalism and its effect on male approach and mating behaviour in a praying mantid

Abstract

Precopulatory sexual cannibalism is an extreme form of sexual conflict because it has the potential to eliminate current and future reproductive success for males. Several female factors such as body condition, mating status and orientation are predicted to impact the likelihood of cannibalism, and males are expected to respond to these factors by altering their approach behaviours in ways that minimize the chance of being attacked (i.e. slower approach and greater distance at mounting). We used the sexually cannibalistic praying mantid Pseudomantis albofimbriata to test whether and how certain female risk factors affect male approach and mating behaviour. We created three different risk treatments by manipulating female body condition, mating status and orientation, and recorded the frequency of cannibalism, male mating success, male approach behaviours and copulation duration. As predicted, female body condition and mating status had an effect on the frequency of sexual cannibalism, and cannibalized males had significantly lower mating success than noncannibalized males. Female orientation was the least important factor in determining the rate of sexual cannibalism in this system, with no significant difference between front- and rear-facing females. Contrary to what we predicted, male P. albofimbriata did not alter/shape their approach or mating behaviours relative to any of the proposed female risk factors of sexual cannibalism. There was also no difference in copulation duration between cannibalized and noncannibalized males. Future studies that investigate the effect of sexual cannibalism on postcopulatory male mating strategies will provide better clarification of the costs and benefits of sexual cannibalism in this system and will also be useful in understanding why males do not respond to the risk of sexual cannibalism in a precopulatory scenario.