Friday, April 17, 2009

Landscape - Eastern Tent Caterpillar

The following is information on Eastern Tent Caterpillar, and insect pest you should be watching for in the landscape.

Our cool spring means that larvae are emerging from egg masses now (13-160 [59 peak] GDD ) and 50 migrating to tree branch forks to form tents. Caterpillars lay a trail of webbing down as they make their way to young leaves to feed. Eastern tent caterpillars are black with tan-colored hairs, irregular blue markings, a white stripe with a yellowish-tan stripe on either side down their back. They prefer to feed on wild cherry, but also readily eat crabapple, ornamental apple, plum, peach, and occasionally birch or ash. Caterpillars feed from 2-598 GDD or while Cornus florida is in full bloom before they mature 50 and leave the tree to search for a suitable location to pupate. The adults emerge in two to four weeks, mate, and females lay eggs in gray foam-like masses with about 150 350 eggs in a mass. Eastern tent caterpillars egg masses are usually laid on twigs or small branches and there is only one generation per year. A number of natural enemies such as assassin bugs, parasitoids, and birds help keep the insect under control. Pruning out egg masses and destroying the eggs in the fall or late winter before egg hatch is an effective cultural method to control eastern tent caterpillar. Some compounds used to control eastern tent caterpillar include: insecticidal soap, B. thuringiensis (Dipel), spinosad (Conserve), chlorantraniliprole (Acelepryn), or pyrethroid products such as bifenthrin. Apply when the larvae are small to increase efficacy and cover both the foliage and the tent.

Information from Brian Kunkel, Ornamental IPM Specialist, UD.

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