Jean wrote:

Egad! There are little worms, green and otherwise, making tatters
of my tree leaves--esp. those of the maples. Will the trees
survive this onslaught? Does anything, preferably nontoxic, stop
them? If something like dormant oil spray would work, I could at
least spray my little Japanese maples. On Monday, I will call my
arborist. Thanks.


They were probably tent caterpillars. This year there has been an
explosion in their population in Massachusetts. They defoliated a lot of
the trees on the main street of Greeenfield, for example.

This is a normal cyclical thing, which peaks every 10 years or so. It
has been reported on forr more than a century. When the tent catepillar
population surges, predators expand to bring them back under control.

The paper here quoted some experts who say that the caterpillars will be
done by mid June and that most of the trees that have been defoliated
will grow new leaves. The exceptions would be trees that were already in
bad shape. They also suggest keeping defoliated trees well-watered.