The cost of mating and the relationship between body size and fitness in males of the parasitoid wasp Nasonia vitripennis

Question: Does male size affect fitness in gregarious parasitoids?

Hypothesis: Larger males achieve higher reproductive success by obtaining more matings when in a competitive scenario and by living longer. Although mating can be costly, larger males are better able to withstand these costs.

Methods: Three experiments: two assessed the effect of size on mating success, one with and one without the presence of a competitor; the third experiment explored the relationship between male size and longevity under alternative mating regimes.

Results: Mating success did not depend on male size even in the presence of an introduced competitor. Mating reduced male longevity, but it did so independently of size.