10 



MONTANA EXPERIMENT STATION BULLETIN 425 



cies which first appeared in Montana (Dawson County) in 1932, 

 has steadily increased in importance and in 1944 was a dominant 

 species in parts of eleven counties. Its greatest population increas- 

 es have been in the valley of the Yellowstone River where its 

 range extends as far west as Forsyth. In western Montana M. 

 mexicanus was dominant with Camnula and M. femur-rubrum 

 and M. bivittatus of secondary importance. 



The 1944 control program during the spring and early summer 

 was decidedly unsuccessful. Very discouraging results were ob- 



