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PROCEEDINGS OF THE NATIONAL MUSEUM 



recorded, and vegetables, oats and raspberries were seriously injured. 

 Early July in that locality was the warmest in 35 years, and that 

 condition may have brought about the early maturity and great 

 abundance of this grasshopper. 



M. bilituratus bilituratus is decidedly migratory at times, and in 

 areas of abundance is usually much more inclined to loose group 

 movements than are most grasshopper species. Parker, Newton, 

 and Shotwell (1955) have described the spectacular flights which in 

 1938-1940 occurred in North Dakota, South Dakota, Montana, and 

 portions of nearby States and Canada. These flights occurred during 

 an outbreak cycle, and a general population increase had preceded the 

 flights. Drake and Tauber (1946) discussed flights which entered 

 Iowa from the west in 1941 and earlier years. 



Corkins (1922) reported on extensive flights in 1920, mainly in 

 Bottineau and Renville Counties, N. Dak., and he noted their re- 

 semblance to the historic flights of spretus. By the use of an airplane 

 one heavy swarm was examined and found to be most dense at an 

 altitude of 500-800 feet, with a few individuals at 1,650 feet. 



Nymphs as well as adults occasionally migrate (Parker, et al., 

 1955, p. 16; Shotwell, 1930, p. 24). 



Early papers (Herrick and Hadley, 1916; Shotwefl, 1930) gave the 

 impression that bilituratus bilituratus is almost omnivorous in its food 

 habits. In recent years, however, entomologists have become keenly 

 aware that many grasshoppers are far from being the general feeders 

 which they were once thought to be, and several investigations 



Figure 5. — Distribution of male specimens of Melanoplus bilituratus bilituratus examined 



from Alaska and Canada. 



