Green alder sawfly larva. (Photo by Christine Buhl, Oregon Dept of Forestry/bugwood.org)
In North America, more than 3,400 documented non-native insect species are established, including the beneficial European honey bee. Fortunately, only a minority of these—about 10 to 12 percent—are invasive, meaning they are causing significant damage to native ecosystems.
The Pacific Northwest is not immune to the global problem of invasive species. In the latest issue of the Arboretum Bulletin, UW insect ecologist and associate professor Patrick C. Tobin profiles six invasive insects that are 1) already here and causing problems, 2) here, but not yet causing significant harm, or 3), not established yet, but represent looming threats.
