TWENTY-NINTH REPORT OF THE STATE ENTOMOLOGIST 7 



A three-week period of cool, damp weather during May and 

 June over much of the State caused the hatch to be uneven and 

 somewhat delayed, especially in Sheridan, Daniels, Roosevelt, Val- 

 ley, Phillips, Blaine and Hill counties. It is thought that these 

 weather conditions may have caused many young 'hoppers to die 

 and may have damaged some eggs so that they did not hatch. It 

 is quite evident that some natural control took place because the 

 infestation in this area was not nearly so severe as indicated by 

 the survey. 



Pondera was by far the most severely infested county in the 

 State. The estimated crop savings realized from the control pro- 

 gram was over 2 x k million dollars compared with slightly less 

 than Yi million dollars damage. Seven hundred sixty-four farmers 

 spread 1441 tons of mixed bait over 177,500 acres of land in the 

 county. 



Other counties which had heavy infestations of grasshoppers 

 and put out large quantities of bait were Teton, Toole, Chouteau, 

 Cascade, Hill, and Yellowstone (see table 1) . 



The control program over the State was, in most cases, quite 

 successful. The estimated savings as a result of the work done was 

 nearly 4V2 million dollars compared with less than V/2 million 

 dollars' damage. Three thousand three hundred twenty-five farm- 

 ers spread 3,668 tons of bait over 671,420 acres of land. The total 

 county expense in putting on the program was $20,007 — the farmers 

 contributed $50,978, and the Federal Government spent $108,525 

 for 'hopper control in the State, making a total cost of $179,511. 



The dominant species in most parts of the State was Melanoplus 

 mexicanus with M. bivittatus ranking second in importance. In 

 the north-central part of the State M. packardi was second to M. 

 mexicanus as the dominant species. It also occurred in large num- 

 bers in Stillwater County. Heavy populations of M. differentialis 

 were found in small areas in Wheatland, Prairie, and Big Horn 

 counties. In spots in Yellowstone and Big Horn counties M. femur- 

 rubrum was observed in large numbers. Heavy concentrations of 

 Disosteira Carolina were found in Golden Valley County. 



The vegetation along the margin of fields and on idle and 

 abandoned land was quite heavy and remained green most of the 

 summer. Because of the abundance of feed there was little mi- 

 gration of grasshoppers into crop land until almost time for harvest 

 so that little damage was done to winter wheat. 



In the eastern part of the State large numbers of M. bivittatus 

 and M. differentialis were recorded dying from what appeared 

 be a fungus or bacterial disease. It was observed that blister 

 beetle larvae had destroyed many 'hopper egg pods in the south- 

 central counties. No other reports of parasites or predators reduc- 

 ing grasshopper populations were received. 



A period of continued cool, wet weather during much of 

 August, September, and October was unfavorable for grasshopper 



