6 MONTANA EXPERIMENT STATION BULLETIN 333 



ployment of one full-time assistant. Dr. H. B. Mills, who has 

 served as Assistant State Entomologist since July 1, 1935. 



The State Entomologist cooperates closely with the Montana 

 Agricultural Extension Service, carrying out much of his work 

 through the county agents. The two agencies have shared with 

 the United States Department of Agriculture the expense of the 

 annual grasshopper survey, the accumulation of data on which 

 has resulted in obtaining much needed federal aid on the control 

 of migratory insects, and all phases of the general problem of 

 insect control. The Agricultural Extension Service does not 

 employ an entomologist, which function is delegated to the State 

 Entomologist. 



In the following pages will be found brief discussions of 

 the most important insect problems in Montana during the 

 past two years, the financial saving which has been made 

 through insect control, and a statement of the needs and plans 

 for future work. 



GRASSHOPPERS ON CULTIVATED LANDS IN 1935 



Severe losses from grasshoppers occurred in 1935. Whereas 

 in 1934 the heaviest infestations were found on nonirrigated 

 lands in northern and north-central Montana, during 1935 the 

 severe infestations were on or near irrigated land along the 

 Yellowstone river. This shift in grasshopper populations was 

 not indicated by the egg survey in the fall of 1934. Park and 

 Sweetgrass counties were properly warned of the impending 

 danger, but the estimates for Stillwater, Yellowstone, Treasure, 

 Big Horn, Rosebud, and Custer counties were entirely too low 

 and gave the farmers a feeling of false security. This undue 

 faith in the survey prediction was unfortunately strengthened 

 by the delayed hatching of the grasshoppers. Until late June 

 and early July little hatching had taken place and farmers, who 

 looked over their fields up to that time, could see little evidence 

 of the trouble which was coming. It had been estimated that 

 about 331 tons of poisoned bait would be needed in the eight 

 counties noted above; actually over 600 tons were used, or over 

 a third of the total for the entire state. See table 6. 



Even though poisoning operations were delayed, thousands 

 of acres of irrigated crops were saved by strenuous campaigns 

 beginning about the first week in July. Through the coopera- 



