Some Effects of endo-Brevicomin Background on Southern Pine Beetle (Coleoptera: Curculionidae: Scolytinae) Aggregation Behavior. Issue 6 (6th September 2021)

• Record Type: Journal Article
• Authors: Sullivan, Brian T; Brownie, Cavell
• Editors: Ginzel, Matthew
• Is Part Of: Environmental entomology. Volume 50:Issue 6(2021)
• Page Start: 1304
• Page End: 1310
• Publication Date: 2021-09-06
• Subjects: biphasic -- multifunctional -- semiochemical -- dose–response -- aggregation; Beneficial insects -- Periodicals; Beneficial insects -- United States -- Periodicals; Insect pests -- Control -- Periodicals; Entomology -- Periodicals; 632.7
• DOI: 10.1093/ee/nvab092
• Languages: English
• ISSNs: 0046-225X

Abstract

Abstract: Semiochemical background in the environment can influence insect orientation to release points of the same or different semiochemicals. endo -Brevicomin is a pheromone component of the tree-killing bark beetle Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae) that has a biphasic dose–response curve, enhancing attraction at low release rates but reducing attraction at high rates. We investigated the effect of artificial manipulation of background levels of endo -brevicomin on D. frontalis responses to sources of aggregation attractant in the field. Traps baited with the aggregation pheromone component frontalin and the host odor alpha -pinene were deployed either with or without a background of endo -brevicomin produced by three surrounding dispensers of this semiochemical each located 20 m away. Two tested levels of endo -brevicomin background caused catches to increase by an order of magnitude above those in the absence of background. Presence of background also altered the beetles' biphasic dose–response when endo -brevicomin dispensers were added to traps. Background reduced or concealed attraction-enhancement otherwise observed for low-release dispensers added to traps, and it decreased the release rate necessary to produce reductions in catches. We propose that spatial variability in abundance of natural, background sources of endo -brevicomin in the environment (i.e., infested trees) is a cause of the observed variability in effects of endo -brevicomin dispensers on southern pine beetle behavior in the field. Furthermore, our results illustrate the potential complexity of the density-dependent effects of biphasic pheromone components on bark beetle mass attack and colonization behavior.