MCH-Based Semiochemical Repellents for Protecting Engelmann Spruce Trees From Dendroctonus rufipennis (Coleoptera: Curculionidae)

Abstract

Spruce beetle, Dendroctonus rufipennisKirby (Coleoptera: Curculionidae), is a lethal pest of spruce trees in North America. Despite decades of research, a semiochemical repellent that consistently and effectively protects spruce trees remains elusive. We evaluated the efficacy of 3-methyl-2-cyclohexen-1-one (MCH) in a proprietary, volatile compound release technology (SPLAT) alone and with two adjuvants, Acerkairomone blend (AKB) and acetophenone + green leaf volatiles (PLUS) to protect individually treated Picea engelmanniiParry ex. Engelm. (Pinales: Pinaceae), and Pi. engelmanniiwithin 11.3-m radius of the individually treated trees from colonization and mortality attributed to D. rufipennisin western Wyoming. Ninety-one Pi. engelmanniiwere baited with frontalin and randomly assigned to one of seven treatments (n= 13): 3.5 g of MCH applied as SPLAT MCH (SPLAT3.5), 3.5AKB, 3.5PLUS, 7 g of MCH applied as SPLAT MCH (SPLAT7), 7AKB, 7PLUS, and baited control (bait only). All repellents except SPLAT3.5 and SPLAT7 significantly reduced colonization of individually treated Pi. engelmanniicompared to the baited control. 3.5PLUS, 7AKB, and 7PLUS reduced colonization most effectively, and all repellents significantly reduced mortality of individually treated Pi. engelmanniicompared to the baited control. All repellents also significantly reduced colonization and mortality of neighboring Pi. engelmannii.

Citation

Audley, Jackson P; Fettig, Christopher J; Steven Munson, A; Blackford, Darren C; Mortenson, Leif A; Mafra-Neto, Agenor. 2021. MCH-Based Semiochemical Repellents for Protecting Engelmann Spruce Trees From Dendroctonus rufipennis (Coleoptera: Curculionidae) . Journal of Economic Entomology. 115(1): 187-192. https://doi.org/10.1093/jee/toab251.