title: Lethal Trap Trees and Semiochemical Repellents as Area Host Protection Strategies for Spruce Beetle (Coleoptera: Curculionidae, Scolytinae) in Utah.
abstract: We tested lethal trap trees and repellent semiochemicals as area treatments to protect host trees from spruce beetle (Dendroctonus rufipennis Kirby) attacks. Lethal trap tree treatments ("spray treatment") combined a spruce beetle bait with carbaryl treatment of the baited spruce. Repellent treatments ("spray-repellent") combined a baited lethal trap tree within a 16-m grid of MCH (3-methylcyclohex-2-en-1-one) and two novel spruce beetle repellents. After beetle flight, we surveyed all trees within 50 m of plot center, stratified by 10-m radius subplots, and compared attack rates to those from baited and unbaited control plots. Compared to the baited controls, spruce in the spray treatment had significantly reduced likelihood of a more severe attack classification (e.g., mass-attacked over strip-attacked or unsuccessful-attacked over unattacked). Because spruce in the spray treatment also had significantly heightened probability of more severe attack classification than those in the unbaited controls, however, we do not recommend lethal trap trees as a stand-alone beetle suppression strategy for epidemic beetle populations. Spruce in the spray-repellent treatment were slightly more likely to be classified as more severely attacked within 30 m of plot center compared to unbaited controls but, overall, had reduced probabilities of beetle attack over the entire 50-m radius plots. The semiochemical repellents deployed in this study were effective at reducing attacks on spruce within treated plots despite the presence of a centrally located spruce beetle bait. Further testing will be required to clarify operational protocols such as dose, elution rate, and release device spacing.
authors: US-Forest Service, Rocky Mountain Research Station, 860 North 1200 East, Logan, UT 84321 (matthansen@fs.fed.us) matthansen@fs.fed.us.
authors: E
authors: E
authors: Matthew Hansen
authors: US-Forest Service, Forest Health Protection, 4746 South 1900 East, Ogden, UT 84403 (smunson@fs.fed.us; dblackford@fs.fed.us).
authors: A
authors: A
authors: Steven Munson
authors: US-Forest Service, Forest Health Protection, 4746 South 1900 East, Ogden, UT 84403 (smunson@fs.fed.us; dblackford@fs.fed.us).
authors: Darren C
authors: DC
authors: Blackford
authors: Synergy Semiochemicals Corp, Box 50008 South Slope RPO, Burnaby, BC, V5J 5G3, Canada (david@semiochemical.com).
authors: David
authors: D
authors: Wakarchuk
authors: US-Forest Service, Rocky Mountain Research Station, 240 West Prospect St, Fort Collins, CO 80526 (lsbaggett@fs.fed.us).
authors: L
authors: L
authors: Scott Baggett
mesh_terms: D000818:Animals; D003510:Cyclohexanes; D007300:Insect Control / Q000379:methods; D007302:Insect Repellents; D010675:Pheromones; D014589:Utah; D048889:Weevils
chemical_list: D003510:Cyclohexanes; D007302:Insect Repellents; D010675:Pheromones; C473568:3-methyl-2-cyclohexen-1-one
keywords: Dendroctonus rufipennis; MCH; bark beetle management; carbaryl; pheromone