Do the benefits of polyandry scale with outbreeding?

Lay Summary Mating can be both costly and dangerous. Despite this, females of many species typically mate more than once and with different males. We found that female seed bugs only benefit from mating with more than 1 male if one of her mates was a different species. Females needed only 1 mating with her own species to maximize her fitness. Thus, multiple mating may be adaptive in areas where the 2 species coexist.