Cabbage white butterflies, the nemesis of the veggie gardener, flit from kale to cabbage to chard, in search of the best host for their eggs after they hatch and larvae start munching. Snell-Rood found that all the bugs start out with a strong innate bias toward green plants such as kale.
But some adventurous and intelligent butterflies may accidentally land on a nutritious red cabbage and learn that the red leaves are good hosts, too.
She has shown, for example, how road-salting has altered the development of curbside butterflies.
Intelligence is defined, of course, from a human perspective.Butterflies are about as different from humans as could belaying hundreds of eggs, living for just a few weeks and possessing brains no bigger than the tip of a pen. A bug-loving biology teacher I know perpetually complains that foolish humans prefer pretty but vapid butterflies to her brilliant pet cockroaches.But entomologist Emilie Snell-Rood at the University of Minnesota and colleagues have found a similar relationship of learning to life-history in butterflies.For example, researchers might ask a child to sort cards according to their color and then suddenly switch to sorting them by shape.Between the ages of 3 and 7, children gradually get better at these tasks.