Picky Eaters Are Less Likely to Be Eaten

By Elizabeth Preston | June 17, 2014 10:08 am



Subsisting on only one food is a poor survival strategy for humans, but a great one for caterpillars. Caterpillar species with very specialized diets are less likely to be plucked from their leaves by hungry birds, scientists have discovered. The less picky eaters are more apt to die (even if their moms praise them in the meantime). The finding is important not just for bugs and birds, but even for the health of the trees they inhabit.

Wesleyan University biologist Michael Singer and his colleagues tested a hypothesis that’s been around for a while: that among insects, more selective eaters are safer. Since these bugs spend all their time on one or a few host plants, the reasoning goes, they may be better adapted to hide on those plants. Insects that wander between many different plant species—with different colors and textures of leaves and branches—may be easier for predators to spot.

The researchers tested this by creating an experiment in the wild. In the forests of central Connecticut, they tied mesh bags around tree branches or small saplings. The mesh allowed insects to come and go, but kept birds out. Each branch or sapling was paired with a nearby one of similar size, which the scientists didn’t wrap up. Over the course of four years, they counted caterpillars on the bagged and unbagged branches to see how many were normally eaten by birds.

Then they broke down their results among the 41 most common caterpillar species crawling on those trees. The species spanned a wide range of eating styles, from specialists that live and feed on a single plant to unfussy generalists that live on many different kinds of plants. Picky caterpillars are safer, the scientists found. Birds prey more heavily on generalist species.

Read more: http://blogs.discovermagazine.com/inkfish/2014/06/17/picky-eaters-are-less-likely-to-be-eaten/#.U6Ch2vldWM4