Issue 1, April 16, 2010

Scouting Watch

Eastern tent caterpillar has hatched in southern Illinois at least as far north as Effingham. Scout crabapple, serviceberry, wild black cherry, hawthorn, and other rose family trees for whitish tents in the twig crotches. Initially, the tents are about two inches long and contain numerous black caterpillars one-quarter to one-half inch long. In southern Illinois on April 13, some of the tents were about three to four inches long. Bacillus thuringiensis kurstaki (Dipel, Thuricide, others), spinosad (Conserve), and other labeled insecticides are effective. Avoid bee kill by only using Btk on flowering trees.

European pine sawfly should be scouted for in southern Illinois. Clusters of these caterpillar-like larvae should be present on Scotch, mugo, and other susceptible pines. Remember that Btk is not effective against these wasp relatives. Labeled pyrethroid insecticides should be effective as well as hand-removal.--Phil Nixon

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