[Dispersion of the nematodes belonging to the Bursaphelenchus xylophilus species group with saw timber in Russian Federation].

Four new records of Bursaphelenchus mucronatus in saw-timbers from the Asian part of Russia (Irkutsk Oblast and Krasnoyarsk Krai, larch, pine and spruce wood) intercepted in St. Petersburg, are described, measured and illustrated. The diagnosis of B. mucronatus is amended and its relationships within species group xylophilus, and especially its differences from a quarantine pests B. xylophilus, are given. The record of the B. mucronatus transition from Asiatic into European part of Russia suggests possible transcontinental way of the xylophilus group penetration with saw-timber. Pest risk analysis of B. xylophilus for the European part of Russia is discussed in scope of the global warming.