Battle of the Sexes?

The spongy undersides of female bed bugs protect the insects from painful intercourse, a study finds.

Feb 16, 2015
Jenny Rood

SWEDISH UNIVERSITY OF AGRICULTURAL SCIENCES, RICKARD IGNELLRather than responding to rough male mating strategies with weaponry of their own, female bed bugs (Cimex lectularius) evolved tolerance via a soft structure that protects them without harming the male, according to a study published last week (February 11) in Journal of the Royal Society Interface.

During mating, the male bed bug punctures the female’s abdomen with a needle-like structure to inject his sperm in her body cavity in a classic example of sexual conflict. To examine whether females respond with resistance, which would escalate the conflict, or tolerance, which would protect the females without damaging the males in return, German researchers from the Christian-Albrechts-Universität and the Helmholtz Centre for Ocean Research in Kiel and the Technische Universität in Dresden examined the female insects with confocal laser scanning microscopy. The researchers found that the covering on the females’ underbellies was rich in the elastic protein resilin, which helped to reduce mating-related tissue damage and staunch the flow of blood without harming the male.

By breaking the cycle of attack and counter-attack adaptations through evolving tolerance, the female bed bugs may instead drive the males to diversify their sexual strategies in new directions, the authors suggested. “We propose that tolerance can drive trait diversity,” they wrote in their paper.

Hat tip: Science News