Larvae of caterpillarlike insects that feed openly on foliage can generally be distinguished by the number and location of pairs of prolegs (leglike appendages, or fleshy stubs) on their abdomen. Larvae of leaf-chewing sawflies (wasps, Hymenoptera) have six or more pairs of prolegs. Caterpillars (butterfly and moth larvae, Lepidoptera) have proleg pairs on five or fewer abdominal segments. Beetle (Coleoptera) larvae have true legs but no prolegs. Fly larvae (such as predatory syrphids, Diptera) have no true legs, but some species have prolegs or fleshy protuberances on their abdomen or on both their abdomen and thorax. Credit: Adapted from an illustration by David Kidd.
