Image of the Week: Gypsy Moth Infestation Continues in New England

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Detailed Description

Gypsy Moth populations are at their highest levels since the 1980s, causing damage to hardwood trees in the New England area.

At the USGS EROS Center, we study land change, operate the Landsat satellites, and maintain the longest, continuously acquired collection of images of the Earth's land surface.

USGS EROS Center (


Date Taken:

Length: 00:01:26

Location Taken: MA, US


A large outbreak of gypsy
moth caterpillars attacked

the hardwood forests of
the northeastern

United States in 2016.

A fungus introduced from
Japan had kept gypsy moth

populations at low levels
since the late 80s.

But low rainfall in 2014,

in the worst outbreak
in over 30 years.

While the caterpillars
thrived in the drought

conditions, this spring's
rainfall made the fungus

effective again.
But the moth mortality

peaked at the END of the
larval stages, after the

caterpillars had already
caused most of the damage.

Valerie Pasquarella, a
Postdoctoral Research

Associate at the University
of Massachusetts Amherst,

is using Landsat data to
track the spread of the

outbreak by comparing new
Landsat observations with

long-term average conditions.
In these season-integrate

maps, blue indicates normal
forest conditions, while

yellow, orange, and red show
decreases in vegetation greenness.

Landsat has not typically
been used to monitor insect

outbreaks, but new tools and
open access to Landsat data

make it possible to quantify
over a large area at a level

of detail that doesn’t work
with aerial surveys alone.