THE SAWFLIES {Chalastogastrd) OF BOULDER 

 COUNTY, COLORADO 1 



By Sievert A. Rohwer 



After having lived many years in Boulder, Colorado, it was a 

 pleasure to work up the sawflies and wood-wasps for the county at 

 Professor Cockerell's request. Although Boulder was for many years 

 my home, it was not possible for me to do much sawfly collecting 

 there, as I was usually in other parts of the state during the best 

 season for these insects. For good collecting grounds I would 

 recommend Boulder Canyon and all of the mountain meadows, more 

 especially those of the Canadian life-zone. It should also be profitable 

 to examine the conifers, as there are many species which feed on these 

 trees. 



In the present state of our knowledge of these insects in Boulder 

 County it seems unwise to give any elaborate tabular arrangement 

 of the few species known to occur there. In this paper more atten- 

 tion will be paid to the localities inhabited by members of the group 

 with the idea of giving information as to how and where to look for 

 them. To enable the insects to be studied easily, they should be 

 pinned with black 2 pins through the right lobe of the mesoscutum. 

 The wings should be partially spread so they can be easily studied, 

 and so as not to interfere with the study of the body. The small 

 species may be mounted on card-points or pinned with micro-pins. 

 If the proper pins are not available, or if time cannot be given to 

 mounting, they may be put into alcohol. 



The adults of this suborder are seldom taken on flowers other 

 than some of the large umbellifers which occur in the Canadian zone. 

 They can however usually be taken by sweeping in meadows, or 

 sweeping various trees and shrubs, more especially different willows. 

 In most cases the adults fly in the spring or early summer. The 



1 Publication of the Colorado Biological Survey, No. 10. 

 1 White pins should not be used because of verdigris. 

 91 



