Complete Destruction of an Evergreen in One Season!
Shade trees, shrubs, hedges, and evergreens, especially arborvitae are subject to damage by a caterpillar that has a curious habit of crawling about in the infested trees in a baglike case, hence giving this insect the common name of bagworrn. The bagworm is fond of willows and maples, particularly silver maple and its varieties and the related boxelder; it is also fond of poplars and mulberry. In 1907, the bagworm attracted greater attention than any other tree defoliator.
If you had a few bagworms last year and did not treat, you will probably have a lot more this year!
Bagworms are easily identified by the spindle-shaped bags of silk, covered with bits of needles or leaves, that they construct around themselves. the silk is very tough, and the bits and pieces of needles or leaves on the bag provide excellent camouflage. The winter is passed in the egg stage. The pale-whitish eggs are protected inside the bag that the female has occupied during the summer. A mass of 500 or more eggs may be deposited by each female. The caterpillars hatch around the first of June. The tiny caterpillars leave the old bag of the mother and begin to feed on the foliage. They immediately spin a bag of silk around themselves and attach bits of foliage to the outside as they feed. The caterpillars carry these bags with them wherever they go, with only the front end of their bodies protruding for feeding and locomotion. The bags enlarge as the caterpillars grow. The full-grown caterpillar is 3/4- to 1-inch in length and is enclosed in a bag that is 1½- to 2-inches long. After reaching maturity, the larvae attach their bags to twigs with a strong band of silk. The caterpillars change into the pupal or resting stage inside the bags in late summer. This period lasts about three weeks, and then the adult emerges. The adult male is a black, hairy moth that measures about 1 inch across the spread wings. The adult female is whitish, worm-like, and has no wings or antennae. The eyes and legs are not functional. The male moths leave the bags and fly to bags containing females where mating takes place. Each female deposits a mass of eggs in the bag, drops to the ground and dies. There is only one generation of the insect each year.
