Pest description and damage The red humped caterpillar is the larva of a 1 inch, gray-brown moth. The mature larvae are yellow with a red head, and the fourth segment is humped. The body has orange, black, and white lengthwise stripes, as well as dark, fleshy "spikes" on it. Young red humped caterpillars are found in clustered colonies that disperse as caterpillars mature. They eat entire leaves (except the major veins) and can cause considerable defoliation. They have been a problem on cherry and other hosts east of the Cascade Mountains.
See Table 2 in:
For more information
See "Caterpillar" in:
Brunner, J. 1993. Redhumped caterpillar. WSU Orchard Pest Management Online (http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=600)