The larval form of the brown-tail moth, an inch-long brown caterpillar with two

The larval form of the brown-tail moth, an inch-long brown caterpillar with two broken white lines on the back, has been defoliating trees on several islands in Casco Bay, and a toxin it carries in its hair can give people who come into contact with it a burning rash. The brown-tail moth, a relative of the gypsy moth, spends around nine months of the year in the larval form, and when trees bud out in the spring the caterpillars emerge from their gray webs to gorge on the trees. The city of Portland is trying to contain the outbreak with insecticides. Details