Exotic Tipula paludosa and T. oleracea (Diptera: Tipulidae) in the United States: Geographic distribution in western Oregon

The geographic distributions of the exotic Tipula paludosa Meigen (Diptera: Tipulidae) and T. oleracea Linnaeus, were estimated in western Oregon, in the northwestern United States. These two exotic crane fly species are agricultural pests in temperate regions of northern Europe where they are native. In Oregon, both species were first documented in the northwestern region of the state and were believed to have spread south. Tipula paludosa was collected at all sampling sites along the coast, at sites in the Willamette Valley, in the Northern Cascade Mountains and south into northern California. This represents a significant range expansion since the first documentation of this species in Oregon 15 years ago. Tipula paludosa was not collected at 5 of the 6 sites in the drier southwestern interior portion of the sampling region. Tipula oleracea, known to be present for only 5 years in northern regions of Oregon but with likely better dispersal abilities, was collected at sites in the Willamette Valley, the southern coast, the southwestern interior and northern California. The continued spread of both exotic species on the west coast of the United States may potentially affect numerous agricultural producers, homeowners and members of the lawn care industry.