THE AUTHOR 



R. J. HOFF is principal plant geneticist with the Intermoun- 

 tain Research Station's Forestry Sciences Laboratory in 

 Moscow, ID. He received a B.A. degree in biology from 

 Western Washington State University and a Ph.D. degree 

 in botany from Washington State University. 



RESEARCH SUMMARY 



In 1985, 14-year-old ponderosa pine in a provenance test 

 in northern Idaho were severely damaged by the gouty pitch 

 midge. Dead or dying tips varied from to 85 percent for 

 individual trees, and to 1 7 percent for provenances. The 

 most resistant provenances came from seed collected in 

 northernmost Idaho and northwestern Montana where the 

 midge is more abundant than in the southern portions of the 

 study area, comprising central Washington, the northern 

 slopes of the Salmon River, and the Bitterroot River of 

 Montana. Resistance to the midge apparently is an inherited 

 trait influenced by degree of exposure of parent trees. 



Intermountain Research Station 

 324 25th Street 

 Ogden, UT 84401 



