title: A Novel Semiochemical Tool for Protecting Pinus contorta From Mortality Attributed to Dendroctonus ponderosae (Coleoptera: Curculionidae).
abstract: Verbenone (4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-one) is an antiaggregant of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), a notable forest insect capable of causing extensive levels of tree mortality in western North America. Several formulations of verbenone are registered for tree protection, but failures in efficacy are not uncommon, particularly when applied during large infestations. A formulation of (-)-verbenone was developed (Specialized Pheromone & Lure Application Technology [SPLAT] Verb, ISCA Technologies Inc., Riverside, CA) and evaluated for protecting individual lodgepole pine, Pinus contorta Douglas ex Loudon, and small stands of P. contorta from mortality attributed to D. ponderosae. SPLAT Verb applied to individual P. contorta resulted in complete tree protection, while 93.3% mortality occurred in the untreated controls. Significantly fewer P. contorta were killed by D. ponderosae within 0.041-ha circular plots surrounding P. contorta treated with SPLAT Verb compared with the untreated control. In a second study, a smaller percentage of P. contorta were colonized and killed on 0.4-ha square plots treated with SPLAT Verb compared with the untreated control. No significant differences in levels of tree mortality were observed between the untreated control and another formulation of verbenone (7-g pouch) or between the 7-g pouch and SPLAT Verb. In a trapping bioassay, no significant differences were observed among captures in multiple-funnel traps at 1, 2, or 4 m from the point of release of SPLAT Verb. Significantly fewer D. ponderosae were collected at 1 and 2 m compared with 8 m. Significantly more D. ponderosae were captured at the farthest distance evaluated (16 m) than at any other distance. Our data indicate that SPLAT Verb is effective for protecting individual P. contorta and small stands of P. contorta from mortality attributed to D. ponderosae at moderate doses. The high levels of tree protection observed are attributed to the ability of applying release points (dollops) at high densities, and a larger zone of inhibition than reported for other formulations of verbenone. SPLAT Verb was registered by the U.S. Environmental Protection Agency for use on pines, Pinus spp., in 2013.
authors.affiliation: Pacific Southwest Research Station, USDA Forest Service, 1731 Research Park Dr., Davis, CA 95618. cfettig@fs.fed.us.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Fettig
authors.affiliation: Forest Health Protection, USDA Forest Service, 4746 South 1900 East, Ogden, UT 84403.
authors.forename: A Steven
authors.initials: AS
authors.lastname: Munson
authors.affiliation: ISCA Technologies Inc., 1230 Spring St., Riverside, CA 92507.
authors.forename: Michael
authors.initials: M
authors.lastname: Reinke
authors.affiliation: ISCA Technologies Inc., 1230 Spring St., Riverside, CA 92507.
authors.forename: Agenor
authors.initials: A
authors.lastname: Mafra-Neto
mesh_terms: D000818:Animals; D000081008:Bicyclic Monoterpenes; D007300:Insect Control / Q000379:methods*; D010675:Pheromones; D028223:Pinus; D013729:Terpenes; D048889:Weevils
chemical_list: D000081008:Bicyclic Monoterpenes; D010675:Pheromones; D013729:Terpenes; C052875:verbenone
keywords: SPLAT Verb; lodgepole pine; mountain pine beetle; tree protection; verbenone