Cotton leaf perforator
Cotton leaf perforator is a pest only in the southern desert areas of California. Early larval instars of the cotton leaf perforator are flattened, yellow to orange caterpillars that bore into leaves and tunnel between leaf surfaces until the fourth instar. They can be distinguished from maggots of leafmining flies by looking with a hand lens for the presence of a head capsule and mandibles. The fourth instar emerges from the leaf and begins skeletonizing leaves. During the molt between the fourth and fifth instar, the larva forms a thin silk shelter and curls into a horseshoe shape inside the shelter. The fourth and fifth instars are green to gray, with two black spots and several smaller white spots on each segment.