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Some effects of endo -brevicomin background on southern pine beetle (Coleoptera: Curculionidae: Scolytinae) aggregation behavior

Formally Refereed
Authors: Brian Sullivan, Cavell Brownie
Year: 2021
Type: Scientific Journal
Station: Southern Research Station
Source: Environmental Entomology


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 endobrevicomin
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 endobrevicomin
in the environment (i.e., infested trees) is a cause of the observed variability in effects of endobrevicomin
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.


biphasic, multifunctional, semiochemical, dose–response, aggregation


Sullivan, Brian T; Brownie, Cavell. 2021. Some Effects of endo -Brevicomin Background on Southern Pine Beetle (Coleoptera: Curculionidae: Scolytinae) Aggregation Behavior . Environmental Entomology. 37: 899-.