1. Vandenberg, N., Rabaglia, R.J., and Bright, D.E. 2000. New records of two Xyleborus (Coleoptera: Scolytidae) in North America. Proc. Entomol. Soc. Wash. 102(1): 62-68.
2. Mudge, A.D., LaBonte, J.R., Johnson, K.J.R., and LaGasa, E.H. 2001. Exotic woodboring Coleoptera (Micromalthidae, Scolytidae) and Hymenoptera (Xiphydriidae) new to Oregon and Washington. Proc. Entomol. Soc.Wash. 103(4): 1011-1019.
Hylastes opacus: Specimens of this Palearctic scolytid have been detected in Oregon, from samples collected in 1998. Hylastes opacus established populations in the eastern U.S. (ME, NH, NY, WV) and Canada (Ontario and Quebec) in the early 90's; however, this is the first report from the western United States. In Europe, H. opacus is a pest of pine plantations, its primary host (particularly P. sylvestris), though other conifers are sometimes attacked (2).
Xyleborinus alni: In surveys conducted between 1996 and 1998, this beetle was discovered in Oregon and Washington; this is the first published North American record for the species. Previous to these findings, X. alni's distribution included central and eastern Europe as well as eastern Russia and Japan. In 1995, this species was identified from four sites around Vancouver, British Columbia, though these records were never published (2).
Xyleborus pfeili: This scolytid beetle is native to Europe, Asia and Africa, and was first detected in the United States in 1992 from Maryland (1). It is part of a group called the "ambrosia" beetles, which damage trees by drilling into the sapwood and feeding on introduced fungal symbiotes. It has been more recently (1997) found in Oregon, a new western North American record (2).
Xyleborus californicus: Another ambrosia beetle, this species is indigenous to Siberia and northern Asia, though it was first described in 1982 from a population established in California and Oregon. In 1994, X. californicus was detected for the first time in the eastern U.S., from Maryland. As of 1997, this species has also been found in Arkansas, Delaware, and South Carolina (1).
Xiphydria prolongata: the "willow wood wasp", a European species previously recorded from Michigan and New Jersey, was found at a single location in Oregon in 1998. Also reported from northern Asia, this species feeds on a wide variety of deciduous hardwood trees including maple, alder, poplar and willow. While the wasp is mainly associated with partially decayed wood, it poses a potential threat because it has been implicated as a passive carrier of watermark disease of willows (2).