Integrated Pest Management · Agriculture and Natural Resources
University of California
Caterpillars are the larvae of butterflies and moths. They damage plants by chewing on leaves, flowers, shoots, fruits, or sometimes boring into wood. Caterpillars have three pairs of legs directly behind the head, and leg-like appendages on some but not all segments of the abdomen, distinguishing them from the larvae of beetles, sawflies and flies.
Caterpillars that attack fruits, nuts, and tubers can burrow into plant parts and hide, which means damage often goes undetected until harvest.
Small moths flying indoors can be pantry pests if you see them near stored food. Their larvae may also produce webbing. Tiny moths near closets may be clothes moths.
Caterpillars under turf may cause yellowing or browning, although these symptoms most often come from other causes.
Caterpillars chew irregular holes in leaves or flowers and can entirely consume seedlings, young shoots, buds, leaves, or flowers.
Some leaf-feeders on woody plants fold or roll leaves together to form shelters. Others create "nests" in foliage, hollow out trails within the leaf, or feed out in the open.
These caterpillars may cause holes in trunks, weakened branches or crowns, and distorted shoot growth.