An awesome example of mimicry and parasitism - beetles as a venereal disease
If you’ve been following for a while, you know that I have a (some would say unhealthy) appreciation for animal parasitism and mimicry. Here’s another awesome example that I got from Jerry Coyne. In this case, the larvae of the blister beetle (Meloe franciscanus)parasitize a species of bee (Habropoda pallida) and act essentially as an STD.
The H. pallida bees don’t colonize hives, but instead female bees live alone in underground nests, feeding larvae with pollen they collect. The beetle larvae hatch from the nest and, all together, crawl up a plant in a writhing, living ball that moves and reacts to stimuli in unison. This cluster (the top picture) is appealing enough to male bees that the try to mate with it - the researchers suggest the beetles might produce bee pheromones. When that happens, the beetles swarm the bee, knocking it to the ground (the middle picture). The bee can clean itself off, but any beetles on the ventral (stomach) side are there for good. (In their observations, researchers found beetle larvae on every single male bee they found!) Next, the beetle larvae is transferred to the female bee’s dorsal surface (back; bottom picture) when the male mates with her. The beetles are then taken back into the bee’s nest, where they feed on pollen and repeat their life cycle.
Watch a movie of the beetle’s life cycle here.