BARK BEETLE PHEROMONE ECOLOGY				Hofstetter Lab page

     Bark beetles (Coleoptera: Curculionidae: Scolytinae) use pheromones and plant compounds 

to focus beetle attacks on host trees (i.e. mass aggregation).  For species that colonize living 

trees, it is important to cooperate with conspecifics to overcome tree defensive mechanisms.  

When two or more species colonize the same tree, species-specific pheromones may

promote successful multi-species aggregations and serve to partition the resource and minimize

interspecific competition.  Cross attraction by species successfully colonizing living trees infers 

a potential mutalism(s), while strong deterrence of heterospecific pheromones suggests an 

antagonistic relation(s) between species.  In the genus Dendroctonus, females beetles initiate attack, 

excavate galleries under the bark, and release aggregation pheromones that are attractive to both sexes.  

Males beetles seek females within trees and produce pheromones which further facilitate aggregation. 

Once beetles mate and females begin to oviposit eggs, antiaggregation pheromones are produced by 

both sexes to reduce potential negative impacts from conspecifics (and interspecifics?) within the host t

tree.

            RESEARCH QUESTIONS AND PAPERS

• Is D. frontalis (the southern pine beetle) more attracted to the WPB lure than the SPB lure?
• Is there variation in capture rates and lure preferences across pine forests throughout Arizona?
• What are the pheromone profiles of D. frontalis and D. brevicomis in Arizona?
• Are secondary bark beetles (e.g., Ips pini) generally attracted to pheromones of primary bark beetles (Dendroctonus spp.) in Arizona?
• Are pheromones from secondary bark beetles disruptive to the communication among primary bark beetles?     Is the addition of monoterpenes to pheromones more attraction to primary bark beetles than secondary bark beetles?
• How does the addition of monoterpenes to bark beetle pheromones alter the predator attraction?
• Are there tree characteristics that are attractive to primary bark beetles? Are these traits chemical, visual, acoustic or a combination?
• Do beetles "learn" chemical profiles from their source tree (i.e. the tree from which they developed) and located trees with similar profiles? Or are beetles attracted to chemicals that imply that the tree is susceptible to attack?