Prominent Moth
Oligocentra alpica
The rather drab adult moth, top, contrasts with the exquisitely colored and camouflaged caterpillars below. The larvae were found feeding on new foliage of Mahonia (Berberis) haematocarpa near Mesquite Wash, Maricopa Co., Arizona, May 2009. Adult moths emerged in June 2009.
The contorted shape of many prominent moth caterpillars is part of their evolved crypsis to rest on their host plant without being noticed by keen-eyed, insectivorous birds. The twigs of Red-berry Barberry (Mahonia haematocarpa) are often covered with prickly, broken-off, leaf bases. When resting on the twigs as these caterpillars do during daylight, they blend in perfectly and are almost impossible to see.
When mature, the caterpillars crawl to the ground and spin a cocoon within the leaf littler. The adult shown here emerged June 15, 2009. No doubt it soon would lay eggs on the host plant. It is not known if the insect completes another generation during the summer or enters into an estivation (akin to hibernation) stage until the following spring.