How do male damselflies and dragonflies reduce competition from sperm left by earlier mates?

In the context of reproductive behaviour within the order Odonata, male damselflies and dragonflies employ specialized mechanisms to ensure their own paternity when facing sperm competition.

Because females often mate with multiple partners, males have evolved to use their accessory sex organs—located at the base of the abdomen—to physically remove or compact the sperm deposited by previous mates before inseminating the female with their own.1234

This process occurs during the unique "wheel" mating position, where the male grasps the female and guides her abdomen to his accessory genitalia. Much of the time spent in this position is dedicated to displacing rival sperm rather than the actual transfer of the male's own sperm. Following copulation, many males also engage in mate-guarding behavior, remaining attached to or hovering near the female while she lays her eggs to prevent other males from interfering before fertilization occurs.3412