Ant Adaptation Day

Good Day!

I have news from my hymenopteran friends. As you know, Entomology was one of my favorite classes that I had the honor of teaching. The Hymenoptera include the social insects such as bees, wasps, and ants. Ants have a plethora of amazing adaptations. You know about the leaf cutter ants that have evolved an advanced agricultural system based on ant-fungus mutualism (relationship that benefits both species). They feed on special structures produced by a specialized fungus that grows only in the underground chambers of the ants' nest.

Well, some ants may be gardeners, others, such as honey ants, herd aphids in and out of their nests like cattle. Ants and aphids share a well-documented relationship of mutualism. Ants feed on the sugary honeydew left behind by aphids. In exchange, the ants protect the aphids from predators and parasites. In fact, honey ants will go to unusual lengths to ensure the health of the aphids in their care.

A few days ago, I found an article where the ole ants are exploited by none other than butterflies! It is usually the opposite situation. We know several wasps that lay their eggs in butterfly larvae and the caterpillar becomes food for the developing wasps. Who would think butterfly larva would adapt to taking advantage of the ants social behavior?

Following is the Associated Press article for your perusal.

updated 3:29 p.m. ET, Thurs., Feb. 5, 2009

WASHINGTON - Butterflies can seem friendly and harmless. But at least one type has learned to raise its young as parasites, tricking ants into feeding it and giving special treatment.

The pupae of the European butterfly Maculina rebeli exude a scent that mimics the ants and make themselves at home inside the ant nest. Once they become a caterpillar they even beg for food like ant larvae, researchers report in Friday's edition of the journal Science.

But, not content just to be fed, the butterflies even manage to demand special treatment, Jeremy A. Thomas of Britain's University of Oxford and colleagues report.

It turns out that ant queens make subtle sounds that signal their special status to worker ants. The caterpillars have learned to mimic those sounds, the researchers say, earning high enough status to be rescued before others if the nest is disturbed.

In times of food shortage, nurse ants have been known to kill their own larvae and feed them to the caterpillars pretending to be queen ants, they added.

In nature, the real ant queen and the caterpillar keep to different parts of the ant colony and would not encounter one another, the report said.

But in an experiment, a butterfly pupa pretending to be an ant queen was placed in a chamber with worker ants and four real ant queens. The ant queens began to attack and bite the caterpillar, but the workers intervened, biting and stinging their own queens, which they then pulled to a far corner of the chamber while other workers attended the pupa.