title: Phytosanitation Methods Influence Posttreatment Colonization of Juglans nigra Logs by Pityophthorus juglandis (Coleoptera: Curculionidae: Scolytinae).
abstract: Several North American walnut species (Juglans spp.) are threatened by thousand cankers disease which is caused by the walnut twig beetle (Pityophthorus juglandis Blackman) and its associated fungal plant pathogen, Geosmithia morbida M. Kolarík, E. Freeland, C. Utley and N. Tisserat sp. nov. Spread of this disease may occur via movement of infested black walnut (Juglans nigra L.) wood. This study evaluated the ability of P. juglandis to colonize J. nigra wood previously treated with various phytosanitation methods. Steam-heated and methyl bromide-fumigated J. nigra logs, as well as kiln-dried natural wane J. nigra lumber (with and without bark) were subsequently exposed to P. juglandis colonization pressure in two exposure scenarios. Following a pheromone-mediated, high-pressure scenario in the canopy of infested trees, beetles readily colonized the bark of steam-heated and methyl bromide-fumigated logs, and were also recovered from kiln-dried lumber on which a thin strip of bark was retained. In the simulated lumberyard exposure experiment, during which samples were exposed to lower P. juglandis populations, beetles were again recovered from bark-on steam-heated logs, but were not recovered from kiln-dried bark-on lumber. These data suggest logs and bark-on lumber treated with phytosanitation methods should not be subsequently exposed to P. juglandis populations. Further beetle exclusion efforts for phytosanitized, bark-on walnut wood products transported out of quarantined areas may be necessary to ensure that these products do not serve as a pathway for the spread of P. juglandis and thousand cankers disease.
authors: Department of Forestry, Wildlife and Fisheries, University of Tennessee, 2506 Jacob Dr., Knoxville, TN 37996 (jackson.audley@gmail.com; mtaylo29@utk.edu), jaudley@vols.utk.edu.
authors: J
authors: J
authors: Audley
authors: USDA Forest Service, Southern Research Station, 200 W.T. Weaver Blvd., Asheville, NC 28804 (amayfield02@fs.fed.us).
authors: A E
authors: AE
authors: Mayfield
authors: USDA-APHIS, Center for Plant Health Science and Technology, 1398 W. Truck Rd., Buzzards Bay, MA 02542 (scott.w.myers@aphis.usda.gov), and.
authors: S W
authors: SW
authors: Myers
authors: Department of Forestry, Wildlife and Fisheries, University of Tennessee, 2506 Jacob Dr., Knoxville, TN 37996 (jackson.audley@gmail.com; mtaylo29@utk.edu).
authors: A
authors: A
authors: Taylor
authors: Plant Sciences Department, University of Tennessee, 2431 Joe Johnson Dr., Knoxville, TN 37996 (wklingem@utk.edu).
authors: W E
authors: WE
authors: Klingeman
mesh_terms: D000818:Animals; D005651:Fumigation; D006358:Hot Temperature; D006842:Hydrocarbons, Brominated; D007300:Insect Control / Q000379:methods*; D031324:Juglans / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D011157:Population Dynamics; D013227:Steam; D048889:Weevils / Q000382:microbiology / Q000502:physiology*; D014934:Wood / Q000737:chemistry*
chemical_list: D006842:Hydrocarbons, Brominated; D013227:Steam; C005218:methyl bromide
keywords: bark beetle; forest product; quarantine treatment; thousand cankers disease; walnut twig beetle