Description: Larvae are gray caterpillars 2" long, with
long brown hair. They eat tree foliage of all kinds.
Eggs hatch in late April or early May and larvae search
for food immediately. At early stages, the damage to
leaves is slight and is often overlooked, but the early
stages are when these pests are most vulnerable to control
by Bt. In their last stage before becoming moths, the
larvae feed in mass, causing overnight defoliation.
In late June or early July the caterpillars stop feeding
and begin their transformation into adult moths.
Solution: The crucial
control period is late April to June 15th. By mid-June
the caterpillars have grown to 3/4" long and begun to
defoliate leaves. By applying Bt ssp. kurstaki at 10-14 day intervals
in April through June (3 or 4 applications), damage
to leaves can be almost totally eliminated. Just 2 applications
are enough to prevent noticeable defoliation. Spraying
with Neem-AwayTM Insect
Spray or PyolaTM Insecticidal
Spray also controls larvae. Use Slick n' Stick Tape and Bug Gum to
form a virtually impregnable barrier around the tree.
Caterpillars feed only at night. During the day they
crawl down to hide in debris on the ground. Caterpillars
cannot cross the Bug Gum.