Anybody noticed the huge number of tents in the Dunmore area?
No. We are not talking about a Boy Scout camp out. And no, it is not emigrants, or even Rainbow people.
These tents are unsightly webby masses that can be found in the trees and shrubs alongside the roads and fields all over the county and are caused by a small, white moth – better known as the Fall Webworm.
Not to be confused with the Eastern Tent caterpillar that builds a similar web in the springtime, this native lepidopteran, known as Hyphantria cunea and sounding like a song title from “The Lion King,” usually appears as an adult in mid-June. These smallish, hairy moths shortly begin to lay eggs on the undersides of leaves. In a week or so, the eggs begin to hatch and young larvae begin to feed on the tree leaves.
As they skeletonize leaves, they also spin a spidery-type web to surround and protect themselves. Birds and some predatory insects seem to be repelled by the cottony, silken mass of the caterpillar home. Daily the larvae will expand their nest, surrounding a few more leaves for food and binding it with webbing.
The caterpillars will continue to grow, shedding their skins several times as they advance through the instars. Small pieces of leaves, dead larvae, and frass or worm excrement will continue to build up in the unattractive tents until these hairy little caterpillars reach full size. Then they move out to pupate in the leaf and bark litter nearby where they will overwinter, emerging as adults next June to once again complete the cycle.
Fall webworms can be found on more than 90 species of trees and shrubbery, but around here seem to prefer cherry, hickory and apple. By late summer the ugly silken tents can certainly change a view shed. The nasty webs may persist throughout the winter, but otherwise don’t really harm the host sources. Seldom do the afflicted trees ever die.
The best way to deal with webworms may be to cut the affected branch, removing and destroying the built up tent before the caterpillars mature. This is most important for high value ornamentals and fruit trees, but easier said than done in tall trees.
There are some pesticides that may help but few will penetrate the silken nests. Simply ripping the webs open with a stick or hoe may help somewhat to expose the inner parts for birds and wasps to prey on the larvae.
Fall webworms may be considered one of North America’s contributions to worldwide pestilence as they have turned up in China, Russia and Europe. Hopefully they are nothing more than unpleasant eyesores and cause little commercial damage. This is hardly a fair trade as foreign, imported insects and diseases such as Gypsy Moth, Emerald Ash Borer, Hemlock Adelgids, Long Horn Beetles and others continue to wreak havoc through American forests and fields.
In the end, nature will run its course. Few trees will be killed or damaged and webworms will continue their cyclic ways. Every four-to-five years, their populations reach a peak and that may be what we are seeing this year. Hopefully those same numbers will crash and leave us free of tent cities next summer.
On the hunt
The White Oak crop is ripening and beginning to fall to the ground where it is quickly hoovered up by deer, turkey and squirrels. These acorns are considered to be the sweetest and the food of preference for lots of wild game. Fawns will often campout under my white oak so that they can be there when nuts fall. Crows and bluejays will pick their share from high in the trees. When flocks of jays fly overhead, you may see some carrying acorns in their beaks.
It is difficult to tell much about the white oak as foliage is so heavy from early summer rains. Several of my trees appear to be barren, hence the war for acorns under the one good tree.
As summer ends and fall gets started, that signals the return of hunting season. Hunters everywhere begin to smile in anticipation of upcoming hunts. Time to fix up the camp, plan the menus, and scout out the best areas for sign and mast. In fact, squirrels season begins this weekend on September 12. Early bear season begins a week afterward, running from September 19 to 25. Archery and the new crossbow season for deer and bear will begin September 26 and run through the end of the year.
Dave is a telescope operator at the Green Bank Observatory and can be contacted at email@example.com