Sperm competition in the damselfly Enallagma hageni Walsh (Odonata: Coenagrionidae): benefits of multiple mating to males and females

摘要: Sperm competition was investigated in the non-territorial damselfly, Enallagma hageni. Using irradiated (sterile) male techniques, last to mate found fertilize up 95% $${\text{(}}\bar x = {\text{80\% )}}$$ of eggs first clutch laid after mating. Dissection females collected before, during, and copula showed that a removes maximum 87% sperm by volume previous mate. These data verify an earlier estimate lifetime reproductive success this species which based on mating success, suggest indirect dissection methods offer minimum estimates precedence. Male E. hageni have ample opportunity benefit from precedence, since at least 10% receptive encountered had already mated once day, but still contained complete or partial clutches eggs. Female directly high precedence because it allows them “exchange” matings for guarding service males during oviposition bouts under water.