Bagworm

Junipers, Leyland cypress and cedar trees can be skeletonized in August by bagworms. Examination of a rapidly disappearing shrub may reveal dozens of brown "bags" hanging from the limbs. The bags are made from the plant's needles and they contain an adult moth larva, who feasts on the plant's greenery.

Unfortunately, once the bag is easily noticeable, it is too late to control the pest with insecticides. From August on, there is no solution except hand removal.

Wear a long sleeved shirt to avoid being scratched by the needles and scales of the host plant. Make a note to spray Bacillus thuringensis (B.t.) next May or June, when the moths have not yet formed their protective bags.

Q: I have a screen of Leyland cypress planted along one side of my property. One of them has a good many bagworm "bags" hanging from the branches. Does it do any good to pull off those bags?

A: It's about the only thing you can do to control bagworms! The bags are full of eggs. When they hatch in late spring, the "worms", which are actually wingless moths, will defoliate more of your Leylands. You won't have much of a screen any more if you let this problem get out of hand. Bagworms are hard to control with insecticides. The best time to spray is once in mid-May and again two weeks later. This is the time when bagworm eggs have hatched but have not yet formed their protective covering.