Joint project of The Bugwood Network, USDA Forest Service and USDA APHIS PPQ. The University of Georgia - Warnell School of Forestry and Natural Resources and College of Agricultural and Environmental Sciences - Dept. of Entomology
http://www.invasive.org/

Great Lakes Information Network:
http://www.great-lakes.net/envt/flora-fauna/invasive/invasive.html

Invasive Species Initiative (through MSU):
http://www.invasivespecies.msu.edu/index.asp

New England Wildflower Society:
http://www.newfs.org/conserve/invasive.htm