Aliens among us: the bear butterfly and its " tentacles»

Meeting a male bear butterfly (Creatonotos Gangis) during the mating season can be a real test of the nervous system. The reason for this is the wiggling, hair-covered tendrils that grow from his abdominal cavity. Even a Stranger from the blockbuster of the same name coughs nervously at the sight of such a sight. Why are they needed?

Their purpose is quite understandable. These antennae are nothing more than coremates: large branched tubes covered with thousands of scales that emit a huge amount of odorous pheromones and attract females. In the normal state, this part of the body of males is invisible and hidden. But as soon as the mating season begins, an influx of hemolymph or air pushes them out. To increase the spread of pheromones and prolong the effect, males additionally quickly flap their wings.

Interestingly, the size of the coremata depends on how voracious the males are in the caterpillar stage. The more leaves of poisonous plants they eat, the more large and effective glands are contained in their tubes. And the more attractive they are for females.