Foraging strategies of caterpillars : Leaf damage and possible predator avoidance strategies

Abstract

An analysis of the foraging behaviors of several species of palatable and unpalatable lepidopterous larvae indicates that palatable caterpillars partition their time between feeding and behaviors that could be related to escape visually oriented predators. Depending on the species, palatable caterpillars do all or several of the following: 1) restrict themselves to the underside of leaves at all times, 2) restrict foraging to night-time, 3) commute to and from their feeding area on leaves, 4) move from the unfinished leaf to a distant leaf after a feeding bout, thus removing themselves from the evidence of their eating, 5) snip off partially-eaten leaves after feeding on them. The less palatable, or unpalatable, caterpillars do not snip off partially-eaten leaves, feed from leaves leaving tattered edges, and are often exposed resting and feeding on the leaf surfaces in direct sunshine. I conclude that some caterpillar foraging behaviors may have evolved under the selective pressure of visually-oriented predators that use leaf-damage as a cue in their searching behavior.