In enemy garb: New explanation for wasp mimicry

Date: February 24, 2017

Source: University of Freiburg

The masquerade is almost perfect. Certain moths of the subfamily Arctiinae are marked with a yellow and black pattern. But these day-active insects have wasp waists and their antennae resemble those of wasps. Their transparent wings are folded in a wasp-like way. For more than 150 years there has been a plausible explanation for this type of imitation, which is commonly known as mimicry. It says that the moths -- just like many hoverflies and other insects -- imitate wasps in order to protect themselves from birds and other hostile predators. According to textbook wisdom, these voracious foes have learned from painful experience.

They have been stung by wasps and since then have avoided any animal that looks like one. In the scientific journal Ecology and Evolution, a University of Freiburg biologist, Prof. Dr. Michael Boppré and his team have now presented an additional hypothesis that goes beyond this traditional view. Their interpretation is that, above all, the moths' appearance deceives the very wasps they are mimicking.

As a rule, insects developing imperfect similarity to wasps is enough to keep learning predators at a distance. Yet the Arctiinae that Boppré observed during his biodiversity studies in South and Central America are different. The biologist says, "Especially when they are in flight, even for the trained eye it's nearly impossible to tell apart the examples from the mimics." That led Boppré to question why these Arctiinae have evolved this near-perfect imitation and what creatures they are trying to deceive. He says, "The answer -- wasps -- is stunningly simple." Wasps hunt other insects as food for their larvae. Yet wasps do not attack each other, even when they are out on hunting flights they do not differentiate the wasps they encounter as originating from their own or other nests. The moths, therefore, are imitating the wasps so that these predators will perceive them as members of the same species and not attack for that reason.

Read more