The black widow male (genus Latrodectus) is usually eaten by the sexually mature female after mating. However, the males of some species have developed an effective strategy to escape death.

Latrodectus hasselti and Latrodectus geometricus (species widespread in tropical and subtropical areas around the world) solve the problem by choosing young and sexually immature females .

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During the last 2 or 3 days before the moulting, the young females have already developed the spermathee, the sperm preservation organs, which are however still covered by the juvenile exoskeleton: the males pierce the abdomen of the females to access the spermateches, where they deposit the sperm which will then be used by the mature female to fertilize the eggs.

The male is thus able to transmit his genetic heritage several times without being devoured, as would be the case if he fertilized a sexually mature female. The study, coordinated by Daniela Biaggio (biologist, University of Toronto), is published on the online pages of Biology Letters.