Skamania County, Wash. -
The Green Alder Sawfly was first detected in the lower 48 states of United
States this spring in Vancouver, WA. Now green caterpillar-like larvae of
the sawfly insects can be found eating the leaves of alder trees along the
Columbia River in Skamania County. Entomologists from the US Forest Service
and Washington State Department of Agriculture are surveying for the new
insect in Western Washington State.
"When green alder sawfly was first found in April, we had hoped to eradicate
a small infestation in Vancouver," said Kathy Sheehan, entomologist with the
U.S Forest Service. "Thanks to an informal network of entomologists,
though, we soon found this sawfly throughout western WA. Now we will be
watching closely to see what effect this non-native species has on alders."
The green alder sawfly is native to Europe and Western Eurasia in addition
to parts of North Africa. It was first discovered in Newfoundland, Canada in
the mid-1990's and first collected in Alaska in 2004. The green alder sawfly
is an accidentally introduced pest of alder trees.
Larvae of the green alder sawfly resemble bright green caterpillars and grow
up to ½- ¾ inches long. The larvae chew holes in leaves and can defoliate a
tree if sawfly populations are high enough. The adults are active in early
spring and resemble a wasp without the stinger and constricted waist.
Experts are uncertain of the impact that this new insect will have on alder
tree health or on our local flora and fauna. As with any organism newly
introduced to our region, there is a concern that economic and environmental
damage to our forests could result.
For more information about the Green Alder Sawfly, visit:
http://www.fs.fed.us/r6/nr/fid/invasives/green-alder-sawfly.shtml or contact
the WSU Extension office at 509-427-3931
No comments:
Post a Comment