- [Mark] This is Mark Isselhardt,
Maple Specialist with the University of Vermont Extension.
And this is another Vermont Maple Minute.
It appears as though the recent, widespread defoliation
related to forest tent caterpillar has ended.
According to Vermont Department
of Forest Parks and Recreation,
there have been no reports of defoliation
attributed to this native insect in 2019.
This is in stark contrast
to the roughly 70,000 acres
of defoliated trees in 2018.
The dramatic decrease is typical
of the boom and bust cycles previously observed.
The cycles will last between two and four years
in Vermont and occur roughly every 10 to 20 years
in some part of the state.
The caterpillars can multiply rapidly
and make their presence known
by consuming large volumes of leaf matter.
During the outbreak,
it is not uncommon for wide areas of forest
to appear brown and almost leafless from afar.
The vast majority of trees will regrow new leaves
to make up for the ones that have been lost.
In rare cases,
some individuals have even been defoliated twice
in the same summer without dying.
At the end of an outbreak,
the caterpillar populations will crash
as a result of a corresponding increase
in several natural predators and natural controls.
Most trees will recover after a few years
of poor growth and this native insect will return
to relative obscurity until the next outbreak.
This has Mark Isselhardt, Maple Specialist
with the University of Vermont Extension,
and this has been another Vermont Maple Minute.