Both sexes of the earwig Euborellia plebeja (Dermaptera: Anisolabididae) mate frequently. The elongated intromittent organs of males are as long as their bodies. Previous studies have revealed that this organ is used to remove rival sperm from the female sperm-storage organ (spermatheca), the length of which is twice that of the female body. The fitness benefit of sperm removal was quantified using two mating experiments with paternity analysis. As expected, given that the sperm-removal organ is shorter than the sperm-storage organ, males gained only about 20% of paternity per single mating with sperm-saturated females. The significance of frequent repeated matings with the same female by males is discussed.
ASJC Scopus subject areas