The Illinois Department of Agriculture, in cooperation with USDA Animal and Plant Health Inspection Service and local communities and agencies, will be applying insecticides for the control of gypsy moth caterpillars in various areas of infestation in northern Illinois over the next few weeks. The insecticide that is usually used is Bacillus thuringiensis kurstaki. This bacterial insecticide is very low in toxicity to humans, pets, or anything else that is not a caterpillar. Other caterpillar species on or near the treated trees are likely to be affected by the sprays.
Because gypsy moth is present in northern Illinois, pheromone traps will be set throughout the state this year. The cardboard triangular traps are about 6 inches long and 3 inches wide. They are usually lime green or reddish orange and are sticky on the inside. There is no insecticide in the trap—only a pheromone or scent that attracts the male gypsy moth. Traps will typically be placed about 1 mile apart over the next few weeks and will be removed in July or August. The presence of a moth in the trap does not mean that gypsy moths are present in the area because other moth species sometimes fly into the trap.