An Unwanted Guest
Q. “Not long ago I went to one of my favorite coffee stops, here in town. This particular well-known chain usually has nice, fairly well-tended landscaping, but one evergreen stood out. It looked like it had brown, tapered holiday lights hanging all over it, only it wasn’t lights. The same day I happened to be passing a local establishment which has a large showing of junipers, and the row next to the road had several bushes, obviously in distress, also hanging with these brown things. What are they?”
The good news: they won’t hurt you. The bad news: they can be deadly to most evergreens and many shade trees – more than a hundred species in fact. The 1½” - 2½” (sometimes longer) elongated brown casings are made up of a silk like material along with twigs, needles, dust, and other plant parts, gathered as the larvae feed. In the fall the male moths come calling on the flightless females, which never left their cocoon. She’s left to lay her egg mass of 300 or so. She’ll spend the winter in the cocoon with her offspring. After the eggs hatch in spring the larvae crawl out the bottom of the bag, begin to feed voraciously, sometimes defoliating whole limbs or trees. Right now they are small and blend in well and are busy making their own silky, well-hidden, water/pesticide-resistant enclosure. The worms manage to cover some territory in their search for food, in spite of the mobile home, but if they remain on the same plant they hatched on, they very well may kill it. Over time their “camper” grows and by the time its noticeable, the camper is moored tightly to a limb by strands of tough silk.
The best way of getting rid of them is to snip the attaching thread, gathering as many as you can reach, as soon as you notice them. They’ll be more noticeable in the late fall/early winter. My method of disposal is to squash them, but that’s a bit nasty. Whatever method you choose, make sure they’re dead because they can winter over in the camper, on the ground. They do have a few natural predators and you can hope you have some of those. If the tree is too tall for you to reach the upper affected limbs, there are chemicals that can be used, but with great caution. Anytime one sprays above one’s head, the risk of being covered with the poison is high. Also some species of plants are sensitive to chemical applications, not to mention the wildlife that may be in the line of fire.
Preventative measures might include an early spring spray with dormant oil or insecticidal soap to get them when they emerge.
Let’s keep an eye out for this little camper and shut it down before it can get comfortable.
Sherrie Ottinger, The Tennessee Dirtgirl
