casebearer, (family Coleophoridae), any larva of a group of moths (order Lepidoptera) that are characteristically light brown with dark heads and feed on apple, birch, cherry, and willow trees. After hatching from the egg, larvae first feed as leaf miners. As they grow they change lifestyles and become casebearers. Their cases, which serve as camouflage and protection, are attached perpendicularly to branches, fruits, leaves, or twigs. The larvae protrude from them to feed. The cases, in which the larvae overwinter, are made from leaves, twigs, silk, and excrement. Typical case shapes vary from that of a cigar to that of a pistol. Most adults in this family are pale brown or gray with a wingspan of less than 12 mm (0.5 inch). The narrow, pointed wings have a long fringe of hair.