Gypsy Moth Spread in North America
The gypsy moth is native to
Eurasia and was introduced to North America in 1868 or 1869 by
E. Leopold Trouvelot
near Boston, Massachusetts.
Since then, its range has been slowly spreading.
The current gypsy moth range in North America (shown in red)
includes all of the
northeastern US and portions of the southeast and midwest, as well as
portions of eastern Canada.
It's distribution in Michigan and parts of Ontario is the result of
an accidental introduction to Michigan in the early 1960's and a
failure of attempts to eradicate this population.
The historical rate of spread has been estimated as:
Spread Rate
Period km/yr
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1900-1915 9.5
1916-1965 2.8
1966-1989 20.9
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(from Liebhold et al. 1992. J. Biog. 19:513-520)
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The gypsy moth is currently spreading at a rate of about 21 km / year
along its border to the west and south.
Since females are not capable of flight, this spread can be attributed
to natural movement of wind-borne 1st instar larvae and
accidental movement of life stages by humans.
We believe that accidental movements of life stages
found new isolated populations just ahead of the expanding
front and these coalesce over time. More detailed
information about gypsy moth spread can be found
here.
Click
here to see some recent work on estimation of the the expanding front.
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![](nosts.jpg) (map courtesy Virginia Tech Univ.)
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The USDA Forest Service is currently beginning
a national project to slow the spread of the
gypsy moth. This project is based upon the use
of grids of pheromone traps along the expanding
front to detect isolated colonies. These colonies
are eradicated or suppressed in order to prevent
them from coalescing and this decreases the rate
of spread.
Click
here
to find out more about this project from this server
or click
here
to visit the national STS homepage.
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![](withsts.jpg)
(map courtesy Virginia Tech Univ.)
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Click
here
to see more maps of historical gypsy moth spread.
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Click
here
, to see the results of annual gypsy moth surveys for
detecting new isolated infestations.
Return to Gypsy Moth in NA
Last modified 10-29-03 by Sandy Liebhold .
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