Every spring we are visited by a native caterpillar known as the Eastern Tent Caterpillar. This pest is found on fruit, apple, and sometimes maple trees. Most commonly you will find this pest on Wild Cherry trees, but you may also see them on other fruit, apple, and occasionally maple trees. The Eastern Tent Caterpillar produces a large silken, woven tent and can cause considerable defoliation to the host plant.
The Eastern Tent Caterpillar overwinters as an egg mass which is laid in late spring on the stems of the host plant. This mass can be seen to the keen eye as a shiny black or purple mass approximately 1-2 inches long. The eggs hatch in early spring as the trees begin to bud. The social caterpillars spin the web in the crotch of a limb and congregate in groups of hundreds within the tent. The caterpillar is black and hairy with a distinct white stripe down its back and two rows of blue oval spots along each side.
The caterpillar grows from its hatchling size of less than an 8th of an inch to its mature larval size of 2-2.5 inches. They feed on the foliage of the host plant and their tent grows in size and stature, as well. The larvae feed during the cool of the day and over night, spending their time in the tent for protection. These tents can be very unsightly and the growing caterpillars have a voracious appetite causing considerable damage and sometimes complete defoliation of the tree. Fortunately, most of these host plants will grow a second crop of leaves.
As the caterpillars reach their mature size, they crawl out of the tree in search of a protected hard surface to pupate into an adult. It is during this migration that the Eastern Tent Caterpillar becomes a real nuisance. They crawl all over the landscape, on sidewalks and driveways, on the side of houses, on cars, and more. Thankfully, this does not last long. The adult emerges from the pupae as a light tan moth which then mate, lay eggs and die; starting the process over again. There is only one generation per year.
The Eastern Tent Caterpillar can be controlled by destroying the tents as they grow. Simply pull the webbing apart and kill the new caterpillars using a stick. If it is a small limb with a large tent, it can be cut out and destroyed. Do not try to burn the tent as this can cause more damage to the tree. There are insecticides which also work well for control. If you use an insecticide, carefully read and follow the label. Big O Tree and Lawn Service is equipped and knowledgeable in the control of this pest and is available to assist.