Azalea Caterpillars Feeding

— Written By and last updated by Carol Hicks

Young azalea caterpillars feeding on a partially defoliated twig. Notice frass collecting below. Photo: SD Frank

Just a short post here to announce the arrival of azalea caterpillars for this year. Azalea caterpillars, Datana major, are among our most attractive caterpillar species. The feed primarily on Rhododendron spp. but I have also found them on blueberries. There is one generation of this pest each year. Adults lay eggs on the underside of azalea leaves where the small caterpillars feed gregariously. As they grow the caterpillars change from yellow with black stripes to black with yellow patches. Usually, these (and other caterpillars0 are noticed by the damage rather than by noticing the actual critters or eggs. Thus, by the time they are noticed azalea caterpillars may have consumed a lot of foliage. Scout for these caterpillars by scanning shrubs for bare twigs then look closer to investigate. You may also see collections of frass on leaves that indicate caterpillars feeding above. If you find a group of them just prune the branch out. In larger infestations or nurseries there are several insecticides active on caterpillars but any product works best on small stages. Find other posts on azalea and related caterpillars here.