³ÉÈËVRÊÓƵ

One thing about evolution — you never know what’s going to influence it. Take the European corn borer, for instance. Researchers have just made a strong case that a certain aspect of its behavior has evolved because of human harvesting of corn. The corn borer, Ostrinia nubilalis, is a pest caterpillar that spends spring and summer feeding on its host corn stalk before spinning a cocoon for the winter. It is almost identical to a related species, O. scapulalis — in fact, until recently the two were thought to be one. But O. scapulalis’s host plant is not corn, but a weed known as mugwort. In a paper in The Proceedings of the Royal Society B: Biological Sciences, Vincent Calcagno, a biologist now at ³ÉÈËVRÊÓƵ University, and colleagues show that, behaviorally, that makes all the difference in the world. For mugwort is neither harvested nor grazed, while corn has been harvested for centuries.