St. Charles Herald-Guide

Tis the season for caterpillars

Rene' Schmit - April 12, 2006

Populations of the Eastern Tent and Forest Tent caterpillars are back and it seems that there are more of them than last year!

Eastern Tent caterpillars are yellowish brown with a yellow stripe down the back and are the ones who web in the crouch of trees. Forest Tent caterpillars are the first cousin to the Eastern Tent caterpillars and although they do not make webs in trees they do leave a fine webbing on the trunk and branches as they move around and forage on the tree canopy. Forest Tent caterpillars are blue in color with a yellow keyhole-like pattern down the back.

Besides Oaks, Sweet Gums and other large canopied trees, Forest Tent and Eastern Tent caterpillars forage on roses and other ornamentals as well. Although these two types of caterpillars can be quite pesty, of greater concern is the Buck Moth caterpillar.

The Buck Moth is a stinging caterpillar and recognized by large black spines and barbs that protrude from front to back on each segment of the body. When touched, these caterpillars cause a burning, itching and reddening of the affected area. Basic home solutions can be used to ease the pain from stinging caterpillars such as ammonia, Clorox, toothpaste, baking soda or meat tenderizer slurries and even tobacco juice. Placing a piece of tape down on the sting and ripping it off will also remove the spines and close the wound. Certainly, caution should be exercised if small children play in an area where these caterpillars populate as children tend to be attracted to their unique form and appearance.

Control for these caterpillars can be accomplished by treating the insects with a pyrethroid such as Merit or Spinosed, or with carboryl such as Sevin or an acephate such as Orthene. It is important to be sure and add a little spreader sticker or liquid soap (1to2ozs. Per gallon of water) to spray solution to assure better contact with the caterpillars. Keep in mind that multiple applications may be necessary over a 6 to 8 week period.