11 



making investigations. Here I found quite different conditions pre- 

 vailing from those observed in western Washington and Oregon in 

 the prevalence of quite a different set of forest trees, notably the 

 lodge-pole pine {Pinus murrayana), the mountain white pine (Pinus 

 monticola), and the Western larch (Larix occidentalis), all of which 

 yielded a large amount of new material and furnished new problems 

 for study. 



Among the more important observations made here was the common 

 occurrence of the same Dendroctonus enemy of the yellow pine 

 observed in northern California and southern and central Oregon. 

 Many trees were found in the vicinity of Buckeye, Wash. , which were 

 dying or had died, evidently from the attack of this insect, since in 

 every tree, of a large number examined, abundant examples of the 

 insect and its work were found. I also found that a serious trouble 

 had prevailed among the white pine in the vicinity of Kootenai, where 

 a large amount of this most valuable timber had died within the past 

 eight or ten } r ears. Upon investigation I found quite conclusive evi- 

 dence that the damage had been caused by another undescribed Den- 

 droctonus allied to P. frontalis , but much larger than this or the one 

 found killing the Western yellow pine. 



Dendroctonus similis was found quite abundant in larch, excavating 

 galleries and depositing eggs in living bark in recently felled trees. 

 Its habits and the common occurrence of its work in standing dead 

 trees indicated that it was one of the principal enemies of this kind of 

 timber. 



In addition to the above observations many others were made on the 

 enemies of the pines, spruces, cedars, larches, birches, poplars, willows, 

 etc. , and a large series of valuable specimens was added to the collection. 



After making quite a thorough investigation of the conditions found 

 in this section of Washington and Idaho, I proceeded, on June 3, to 

 Pullman, Wash. , where I visited the Agricultural College and Experi- 

 ment Station and called on the entomologist, Professor Piper. 



June 4c Professor Piper took me into the forest at the base of Cedar 

 Mountain, Idaho, where a few hours were spent in successful collection 

 of insect enemies of the spruce, fir, pine, and other trees in this region. 

 Many new observations were made here and much new material col- 

 lected. 



June 5 was spent with Professor Aldrich, entomologist of the Idaho 

 University and Agricultural Experiment Station, who was naturally 

 much interested in the object of my trip, since it was partly through 

 his suggestion that this work was undertaken. 



On June 6 I made another excursion into the forests of Cedar Moun- 

 tain in company with the botanist of the University of Idaho, Pro- 

 fessor Henderson, and three students from the botanical and entomo- 



