126 THE MONTANA EXPERIMENT STATION 



not noticeably decreasing and increasing in numbers in different 

 years as is so often the case with insect pests. Wie have not sys- 

 tematically examined the many hundreds of square miles of territory 

 covered by this tree surrounding this valley, btit we have been in 

 the woods in many places and have invariably found the species in 

 abundance. So abundant and general has the insect been found 

 ttiat we have the impression that very much the greater part of 

 the whole area in this vicinity on which this tree grows, is afifected 

 with it. At least this is true of the country close about Bozeman. 



Directly south of Bozeman at a distance of seven miles, the 

 mountains rise abruptly from the edge of the nearly level valley 

 and to the northeast at a distance of about five miles, the Bridger 

 range ends abruptly among the foothills. The writer often goes to 

 the mountains in these two directions for an outing and to collect 

 specimens, and has particularly observed the insect on such occa- 

 sions. We are, therefore, more familiar with the situation regard- 

 ing this species in these localities than elsewhere. On such visit 

 to the mountains in a canon and on the nearby hill slopes, in examin- 

 ing for this moth, it is unusual to find even a single tree that is not 

 affected. On several occasions we have failed to find even a siftgle 

 uninjured tree, and on affected trees it is with difficulty, and only 

 after extended search, that one is able to find a single uninjured 

 cone. Not only ^ are the cones of lower limbs and smaller trees 

 attacked but of the tips of the trees as well. This has been detef"- 

 mined by climbing to the tops of the trees and examining. The ex- 

 tent to which individual cones are injured is discussed in another 

 paragraph. It would be very difficult and expensive to determine 

 with anything like approximate accuracy the percentage of injury 

 by this insect, and the value of such precise information would not 

 justify the cost. We have, however, made a careful, though very 

 rough estimate, of the percentage of injury over the affected area 

 with which we are most familiar and believe that under five per 

 cent of the seeds escape. 



PREVIOUS LITERATURE. 



Mr. D. W. Kearfott was the first to mention this insect in liter- 

 ature, referring it to the genus Cydia, and giving it the specifice name 

 of pseudotsugana in reference to the botanical genus to which the 

 host-tree belongs. The description and brief notes were published 



