Butterfly-Ant Symbiosis

Butterfly-Ant Symbiosis

A Malaysian Blue caterpillar  can develop into an adult without the help of ants, but has a much greater risk of falling prey to predators and parasites. Female blues look for both host plants and Weaver Ants, laying eggs when the ants are present. Weaver Ants, a numerous and aggressive species of ants, offer caterpillars reliable protection. The ants transport young caterpillars around host plants to help them find food. In return, they "milk" the older larvae for a sweet secretion.

Museum staff traveled to Malaysia to research ant-caterpillar association. They discovered that different ant castes play different roles in tending caterpillars, and that major ants fight minor ants for the right to tend caterpillars. This defies standard theory that ants act in unity for the common good of the ant colony

Many of the 6,000 species of the butterfly family associate with ants. The complexity and beauty of such interactions in the Malaysian tropics attracted research on the subject. Lycaenid caterpillars may have special organs that attract and appease ants. Some species cannot survive without ants. For example, some lycaenid caterpillars are taken by ants into the nest and are allowed to eat ant larvae in exchange for a sweet secretion from the caterpillars. Some even evolve ant-like pheromones, so they pass as ants instead of invaders.