Green-striped mapleworms have been found in the Quincy area. They are found sporadically in the western and northwestern parts of Illinois. These caterpillars feed voraciously on red, sugar, and silver maples. They sometimes feed on oaks as well. Green-striped mapleworms are covered with broad, light-green stripes and have bands of black spines on each segment. They also have two long black filaments that stick up like antennae behind the head. They pupate and emerge as rosy maple moths with a 1- to 2-inch wingspan. The moths are yellow with reddish markings on the wings. They spend the winter as pupae, and there are two generations per year in southern states.
Typically, green-striped mapleworms are present in very high numbers, and they completely strip large trees of their leaves. By the time they are noticed, the caterpillars are too large to be effectively controlled. Small larvae can be controlled with Bacillus thuringiensis kurstaki (Dipel, Thuricide) and various other insecticides. However, large larvae are usually only controlled by using heavy compression between boot and pavement. This insect tends to occur in the same small area--usually on the same trees--year after year. Where there has been an infestation, keep your eye out for a possible second generation later in the summer or for their appearance earlier in the summer next year.