Tent Caterpillars are Hatching!

Tent Caterpillars are Hatching!!!!

    Eastern tent caterpillar egg hatch has started.

     "When temperatures are in the upper 70s most of the eggs hatch in eight to ten days, however, highs in the 50s can spread hatch out over a month," said Lee Townsend, Extension entomologist in the University of Kentucky, College of Agriculture. "These caterpillars are basically inactive below 50 degrees so it's easy to see how great an effect temperature has on them."

     The tent caterpillar, which gets its name from the silken tent it constructs in tree branches, prefers wild cherry but also feeds on peach, apple, crabapple and other trees.

     A patient approach will allow any early natural control, such as heavy rains or freezes, to have an effect, and we need to keep in mind that treating too early can mean that additional applications may be needed.  Spraying will be most effective when the nests are established and the caterpillars are actively feeding.  Waiting until the nests are about the size of a baseball or softball should be about ideal. (NOW!)

    Natural enemies play an important role in reducing eastern tent caterpillar numbers in most years. Caterpillars are frequently parasitized by various tiny braconid, ichneumonid, and chalcid wasps. Several predators and a few diseases also help to regulate their populations. 

     Prevention and early control is important. Removal and destruction of the egg masses from ornamental and fruit trees during winter greatly reduces the problem next spring. In the early spring, small tents can be removed and destroyed by hand. Larger tents may be pruned out and destroyed or removed by winding the nest upon the end of a stick. Burning the tents out with a torch is not recommended since this can easily damage the tree.

Young caterpillars can be killed by applying an insecticide containing Bacillus thuringiensis var kurstaki. Larvae within the tents are protected beneath the webbing and are more difficult to kill with an insecticide.

Hardin County Extension Office (765-4121) www.hardinext.org is an excellent source of information on insect pest management, as well as the UK entomology department's web site at www.uky.edu/Agriculture/Entomology/enthp.htm.

Eastern Tent Caterpillar