THE AUTHORS 



GENE D. AMMAN is project leader of the Mountain 

 Pine Beetle Population Dynamics research work unit in 

 Ogden, UT. He joined the work unit in 1966. Prior to 

 joining the Intermountain Station, he was research 

 entomologist with the Southeastern Forest Experiment 

 Station in Asheville, NC, doing biological control and 

 ecological research on the balsam woolly aphid. He 

 began his career with the Rocky Mountain Forest and 

 Range Experiment Station in Fort Collins, CO, as 

 research assistant on sampling populations and mor- 

 tality factors of mountain pine beetle and spruce bark 

 beetle. He has B.S. and M.S. degrees from Colorado 

 State University and a Ph.D. degree from the University 

 of Michigan. 



JUDITH E. PASEK is research entomologist with the 

 Rocky Mountain Forest and Range Experiment 

 Station's Protection and Improvement of Trees in the 

 Great Plains research work unit in Lincoln, NE. At the 

 time of this study, she was biological technician on 

 the Mountain Pine Beetle Population Dynamics 

 research work unit in Ogden. She holds a B.S. degree 

 from the University of Michigan, an M.S. degree from 

 the University of Missouri, and presently is a Ph.D. 

 degree candidate at the University of Nebraska. 



ACKNOWLEDGMENTS 



We acknowledge the helpful reviews of an earlier 

 draft of this manuscript by Drs. A. A. Berryman, 

 Washington State University, Pullman; J. L. Foltz, 

 University of Florida, Gainesville; R. A. Haack, 

 Michigan State University, East Lansing; M. W. Stock, 

 University of Idaho, Moscow; and R. N. Coulson and 

 T. L. Wagner, Texas A. & M. University, College 

 Station. We also gratefully acknowledge assistance 

 from C. E. Jensen (now retired), Intermountain 

 Research Station, Ogden, in developing the three- 

 dimensional relationships in the data, describing them 

 algebraically, and reviewing the manuscript. 



RESEARCH SUMMARY 



Some effects of ponderosa pine {Pinus ponderosa 

 Dougl. ex Laws.) phloem thickness on mountain pine 

 beetle (Dendroctonus ponderosae Hopkins [Coleoptera: 

 Scolytidaej) were studied in relation to beetle attack 

 and gallery densities. Brood production was positively 

 related to phloem thickness, beetle attack density, and 

 egg gallery density, but showed an asymptotic rela- 

 tionship at high attack and gallery densities. Female 

 length was positively related to phloem thickness but 

 negatively related to increasing egg gallery density. 

 Significantly greater proportions of females emerged 

 from medium and thick phloem than from thin phloem, 

 but sex ratio was not related to attack density. The 

 time of emergence was delayed in thin phloem com- 

 pared to medium and thick phloem. 



June 1986 

 Intermountain Research Station 

 324 25th Street 

 Ogden, UT 84401 



