Rates for the various stages and aspects of the beetle population were estimated 

 by Cole and Annnan (1969) from historical records of beetle outbreaks. It remained 

 only to combine these data with the model for the development of the tree population 

 to generate a synthesis of the interaction of the pest and its host. 



The logic of this mortality model is diagramed in figure 3. The cycle for the 

 beetle population is 1 year in length. Annual tree mortality is deducted for each 

 annual cycle. However, the other features of the trees are changed only at the end of 

 the longer tree prognosis cycle. 



A report being prepared by W. E. Cole and A. R. Stage'' will provide more detail 

 about the mountain pine beetle population model. 



^W. E. Cole and A. R. Stage. Intermt. For. and Range Exp. Stn., Ogden, Utah. 

 (Ms. in preparation.) 



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