PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



issued 



SMITHSONIAN INSTITUTION 



U. S. NATIONAL MUSEUM 



Vol. no Washington : 1959 No. 3416 



GRASSHOPPERS OF THE MEXICANUS GROUP, 

 GENUS MELANOPLUS (ORTHOPTERA; ACRIDIDAE) 



By Ashley B. Gurney ^ and A. R. Brooks 



Introduction 



Since the historic outbreaks of the Rocky Mountain grasshopper 

 (Melanoplus spretus (Walsh)) in the 1870's, the close relatives of that 

 species, especially the one recently called M. mexicanus (Saussure), 

 have been of great economic importance in the United States and 

 Canada. The present study was undertaken to clarify the status of 

 the various taxonomic entities in this complex, and we hope it will 

 stimulate further clarifying studies. We have also attempted to 

 summarize briefly the more important information on the biology of 

 each species. 



For many years the status of spretus has been a puzzle to ento- 

 mologists because no specimens have been collected since the early 

 1900's. Gradually the opinion developed that spretus disappeared 

 because it was the migratory phase of a normally solitary grasshopper, 

 and it was supposed that mexicanus was that species. Om* study of 



• Entomology Research Division, Agricultural Research Service, U. S. Department of Agriculture. 

 ' Entomology Section, Canada Department of Agriculture Research Laboratory, Saskatoon, Saskatche- 

 wan, Canada. 



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