|College of Agriculture|
April 4, 2003Eastern Tent Caterpillar Status
By Lee Townsend, Extension Entomologist
Department of Entomology
University of Kentucky College of Agriculture
Most Eastern Tent Caterpillars (ETC) examined this week were still relatively small (3/8" inch to 3/4 inch long) with tents slowly getting larger. The small caterpillars are feeding on expanding foliage but damage is evident only upon close inspection of leaves and buds.
ETC larvae are in an ideal size range for application of control measures based upon tree injection, foliar sprays, or physical removal of tents (See the March 27, 2003 update for details on product alternatives). They should remain that way for about 7 to 10 more days. Caterpillar management should be accomplished while the insects are still in a gregarious stage rather than later when they instinctively begin to disperse.
ETC caterpillars will relocate their tents in a tree once or twice as they continue to develop this spring. Initial tents are constructed within 2 to 3 feet of the originating egg mass, usually out on limbs and at angles with smaller limbs or branches. As the caterpillars grow, they will tend to abandon their initial tents and build new, larger ones several feet away in major branch forks near or at the trunk. New tents probably will include caterpillars from several smaller nests on the tree that coalesce into the larger aggregations. The overall effect can appear to be an increase in tents but actually will lead to fewer, larger nests near the center of the tree. Abandoned tents will begin to fray and deteriorate due to lack of maintenance.