Please report any known or suspected infestations of green Green Alder alder sawfly to the UAF ( Cooperative Extension Service, pulveratum) Sitka District at 747-9440, located at UAS Sitka Room 122.

GPS coordinates of known locations of the green alder sawfly will help in determining the extent of this which probably overwintered in Sitka. UAF Cooperative

For more information on the green Extension Service alder sawfly, visit: Sitka District http://www.fs.usda.gov/Internet/F SE_DOCUMENTS/fsbdev2_038062. pdf UAS Sitka 1332 Seward Ave. (Bob Gorman, Resource Sitka, AK 99835 Development Faculty, UAF Phone: 907-747-9440 A Threat to Sitka and Cooperative Extension July 2013) Southeast Watersheds

Green Alder Sawfly ()

The green alder sawfly (Monsoma This insect is a potential threat to pulveratum) has recently been alder which is an important tree identified on red alder (Alnus rubra) species in Alaska and the Pacific trees in Sitka along Halibut Point Northwest. Alder moves into Rd. and Sawmill Creek Rd & Jarvis disturbed sites with roots that St. This is the first report of this stabilize the soil and in autumn invasive species in southeast Alaska. the fallen leaves rapidly The green alder sawfly is native to decompose into fertile soil Europe and North Africa where its The larvae are pale green in color up to 5/8 inch long and 1/8 inch thick humus. Repeated defoliation of preferred host is the European grey with a darker green lateral stripe. The alders by the green alder sawfly alder. It was first reported in North green alder sawfly belongs to the is associated with alder being America in 1995 in Newfoundland, displaced. Along watersheds Canada. In 2004 it was first insect order which also includes bees, wasps and ants. At the and the banks of streams, rivers collected in Alaska near Palmer. and lakes, loss of alder could Since 2007, the green alder sawfly end of the growing season the green alder sawfly larvae fall and burrow have serious implications for fish has been documented defoliating several inches into the ground or habitat. thin-leaf alder (Alnus glutinosa) in wood to overwinter. In early spring numerous locations in south-central Identified green alder sawfly Alaska, eliminating alder in some the larvae pupate and change life should be destroyed using any watersheds. form into a winged adult about 3/8 reasonable means like hosing inches long with a black head / thorax off infested tree leaves, picking The larval stage of the green alder and the abdomen is black with white off leaves, crushing or drowning sawfly resembles a caterpillar. It is a or yellow stripes, resembling some larvae, shaking trees and voracious feeder which defoliates wasps. In May the adult emerges crushing green alder larvae. leaves leaving only the leaf veins from the soil, flies up and lays 1–5 Birds readily feed on the larvae. and stem. eggs on the underside of alder leaves. The biological control B.T. is Within two weeks the larvae emerge not effective on . and begin feeding on alder leaves. Chemical control options will The larvae mature in six weeks. be provided as information becomes available.