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The pine wood nematode, Bursaphelenchusxylophilus (Steiner and Buhrer) Nickle, causes a wilt of pines in Japan. Severe damage to forests in Japan have been occurring for the past 30 years. Recently, the nematode has been found on conifers throughout the United States. Little is known of the biology and etiology of the pine wood nematode in North America. At present, there appears to be little threat to native coniferous forests of the United States and Canada. This is indicated by the wide host range and extensive geographic distribution of the nematode, association of the nematode on trees severely weakened by insects and diseases, and presence of the nematode in the United States since the early part of this century. Monoculture of susceptible conifers, offsite plantings and the introduction of potentially more effective vectors could, however, result in an increased damage by the nematode.

In a tick-spirochete survey conducted from all 1989 through fall 1992 in north-western Wisconsin, 4,256 birds (composed of 91 species) were examined for ticks. Infestations were recorded for 400 birds (composed of 30 species). Of 1,184 ticks taken from 335 birds (composed of 26 species), 60 (5%) Haemaphysalis leporispalustris (Packard) from 8 species of birds were infected with the Lyme disease spirochete. Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. Similar surveys conducted in 1990 and 1991 in Minnesota and Michigan yielded 223 H. leporispalustris from 61 birds (composed of 23 species), all free of spirochetes. However, 1 B. burgdorferi-infected Ixodes scapularis (Say) was found on 1 bird species in Minnesota. Most ticks were collected in fall from ground-foraging birds such as thrushes and sparrows. These results confirm that tick-infested birds are important in disseminating Lyme disease spirochetes and may also play a role as sources for infecting ticks.

Radio transmitt ers were successfu lly placed on 10 barred owls (Strix varia) during 59.65-66 and the movemen ts of the owls were followed with an automatic radio-tra cking system for a total of 1,182 days. More than 28,000 owl locations were sampled from some two million locations recorded. These locations , along with habitat availabil ity informati on, were programme d for computer analysis to determine intensity of habitat use. Barred owls showed consisten t and highly significa nt preferenc e or avoidance for different habitats despite changing seasons, phenology , weather condition s, and years.The order of habitat preferenc e in decreasin g intensity of use was oak (Quercus spp.) woods, mixed hardwoods and conifers, white-ced ar .' (Thula occidenta lis) swamps, oak-savan nas, alder (Alnus spp.) ..amps , 4marshes, and open fields.