and does not provide a very large inhibitory shield 

 around the tree under attack. We concur with a previ- 

 ous hypothesis that suggests aggregation pheromone 

 plumes larger than a single tree may be responsible for 

 redirection of attacks, including some randomness, on 

 a new tree. More research is necessary to more fully 

 understand the behavioral sequence of the coloniza- 

 tion process and spatial and temporal influence of 

 inhibitory pheromone(s). Inconsistent results in at- 

 tempts to apply inhibitory pheromones in a manage- 

 ment scenario attest to insufficient knowledge of their 

 full role in mountain pine beetle chemical ecology. 

 Results from this preliminary study, however, provide 

 important concepts necessary for linking our model of 

 mountain pine beetle chemical ecology and dispersal 

 (Powell and oth6rs 1996) to appropriate mountain 

 pine beetle behavior observed in the field. 



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