- [Mark] This is Mark Isselhardt, Maple Specialist
with University of Vermont Extension
and this is another Vermont Maple Minute.
As late summer progresses,
so-called late season defoliators
are beginning to become visible in Vermont woods.
Two such insects are Maple Leaf Cutter
and Maple Trumpet Skeletonizer.
The first reported damage
from Maple Leaf Cutter was in 1911
when this insect was responsible
for defoliating 25 acres of Sugar Bush in New York.
Maple Leaf Cutter larvae cut about
a half-inch diameter round hole in Sugar Maple leaves.
The feeding begins as leaf mining,
then takes place under the protection
of a disc of leaf material.
As the larvae malts, it moves to a fresh section of leaf
and uses a larger and larger disc for protection.
Mortality of overstory trees
is rarely associated with this insect,
but occasionally, understory trees could die
as a result of severe injury.
Maple Trumpet Skeletonizer is found primarily
on Sugar Maple and Red Maples.
Their larvae stage feeds on the underside of leaves
between two major veins.
As the larvae grow,
they form a long black tube of its own waste, or frass,
inside a slightly rounded leaf.
By the time the leaf damage has become widely visible,
trees have produced a majority of their energy
for the summer and upcoming winter,
and while unsightly,
these two native insects are not responsible
for significant impact to the host tree's health and vigor.
This is Mark Isselhardt, Maple Specialist
with University of Vermont Extension
and this has been another Vermont Maple Minute.