Azalea Caterpillar

Just after the 4th of July I start looking for “The Red Heads”, I patrol the ground about once a week, until the month of October. This little brown moth is one of my biggest pest problems at Cypress Gardens. If left unchecked this pest could easily defoliate 150 acres of azaleas.
The eggs are laid on the underside of a leaf about 6 inches from the branch tip. The white pinhead size eggs are laid in clusters of 50 or more beginning in early summer. The young caterpillars stay together at first and skeletonize the leaves on a single branch. This is the best time to find the red heads before they do much damage. I look for otherwise healthy azaleas with a single branch with dead leaves. Usually on closer inspection I will see tiny black droppings on top of the leaves and the young caterpillars and empty eggs under the leaves. Killing them is easy now, just pick off the leaf with the caterpillars and drop on the ground and smash them. When they get a little bigger they will spread out over the Azaleas and defoliate the plant stem by stem. One might mistake this for deer damage but the deer eat the tip of the stem first and nibble down , the azalea caterpillar eat their way up the stem. Once they spread out hand picking is impossible because they can be difficult to find and we have so many azaleas to search.
Over the years I have tried many types of pesticides and even Bt, but nothing works as well or as fast as a bacteria call Spinosad,. I find that it kills the caterpillars within a few of hours. Spinosad can be found in several commercial products, I buy it at a local farm supply under the name Ferti-lome Borer, Bagworm, and Tent Caterpillar Spray. Another product is called Conserve SC. I can mix up a gallon of spray and keep it on hand as I check the gardens for caterpillars. It will still be effective after 2 weeks. I am currently using a bottle of Ferti-lome leftover from last year and it is still good. Be careful using Spinosad it will kill butterfly caterpillars as well. I use it only on Azaleas.