Credit: istockphoto/LHENRIK_L

Warming could cause insects of some species to starve even when surrounded by prey, a study suggests.

A team of scientists led by Ulrich Brose at the University of Göttingen in Germany gathered data on the metabolism and feeding habits of three species of predatory beetles in temperatures ranging from 5 to 30 °C1. Beetles feeding on insect larvae, which are relatively immobile, caught prey at the same rate in cool and warm conditions. Beetles that fed on mobile prey such as fruit flies, however, captured food more often at higher temperatures. In part that's because mobile prey were more active in a warmer environment and thus encountered predators more often. But despite the higher capture rate, the overall energy efficiency of these predators dropped dramatically, owing to an increase in metabolism, which boosted energy expenditure.

The team's ecological model suggests that future warming could prevent some types of predatory insects from garnering enough energy to support their revved-up metabolism.