Brown-tailed moth nests are constructed around branch-tip leaves and anchored to twigs. Each nest could contain from 30-400 caterpillars. (Photo courtesy Safeyard Organics)
In a couple of months, brown-tailed moths will be emerging from their overwintering nests.
This caterpillar is covered in tiny poisonous hairs that become airborne as the caterpillar molts and sheds it skin. These barbed hairs function as tiny, microscopic needles that can penetrate a light shirt. The hairs carry a toxin that causes a severe rash to the skin, respiratory problems, and extreme eye problems. These hairs remain toxic for several years after being shed and can be problematic if disturbed by yard work.
Now is the time to check trees for nests. The nests look like leaves that have not fallen off the tree, and most often are at the very top of the tree. The nests are silken tents constructed around branch-tip leaves and anchored to twigs. Each nest could contain from 30-400 caterpillars.
The brown-tailed moths can be found in several diverse types of trees: oak, white birch, maple, weeping willow, beech, and fruit trees.
Trees with just a few nests, say one to two out of seven-eight trees, may only be slightly bothersome, and no further action is usually necessary. Trees with one or more nests, located close to a house, deck, flower beds or parked vehicles should be treated. The nests can be removed, or the tree sprayed or injected.
The brown-tailed moths in Lincoln, Knox, Sagadahoc, and Kennebec counties are not as widespread as they were a year ago. Last spring’s cool weather contributed somewhat to this decline. They also have moved inland and are more noticeable in Somerset and Penobscot counties. Check surrounding area or have a professional check it. A professional tree inspector can usually tell if the nests are from this year or last.
For controlling brown-tailed moths, an arborist can remove branch-tip nests late winter or very early spring. The tree can be treated in April or May by trunk injection, soil injection, and drench. As the tree leaves out, organic and non-organic treatments may be applied to the entire tree. All applications of pesticides should be done in strict accordance with label directions and precautions should be taken to protect both yourself and the environment.
(David Brown owns Safeyard Organics, a landscape tree and property pest inspector and applicator. For more information, go to safeyardorganics.com, or 333-0681)
