INSECT PEST .SURYEI BULLETIN 
. • . • 
Yol, 21 . Supplement No, 
. THE SPEblES AND DISTRIBUTION OP GRASSHOPPERS 
IN THE 1939 OUTBREAK 
Robert L, Shotwell, Entomologist 
Burfiflu of Entomology and Plnnt Quarantine 
United States Department of Agriculture 
The year 1939 was the sixth year in which the species of grass- 
hoppers were recorded,., for the several States included i,n the annual 
grasshopper survey., ; , Data for the 1934, 1935, 1936, 1937, and 1938' col- 
leetions were published as supplements to the Insect Pest Survey Bulletin 
as follovrs: Volume ,14, No, 9; volume 16, No, *5; volume 17, No, 3; volume 
18, No, 6; volume 19, No, 4, 
In 1939 22 States were included in this project and 131,605 speci- 
mens were collected in their typical grasshopper habitats, Pred E, Skoog, 
survey supervisor, made the identifications and much credit goes to him 
and to the rest of the survey unit of the grasshopper control project 
for the gathering of data concerning developments within the infesta** 
tions during the active grasshopper season. The following summary of the 
general situation during 1939 is based on data gathered by this unit. 
General Situation in 1939 from an Economic Standpoint 
In 1938 unprecedented flights of Melanoulus mexicanus Sauss . in 
the Northern Great Plains area invaded western North Dakota, eastern 
Montana, Wyoming, the Black Hills section of South Dakota, western 
Nebraska, and the Red River Valley of Minnesota and North Dakota, Because 
of the 1938 flights, large areas of depleted range land in eastern 
Montana and the bottom land along the Big Missouri and Little Missouri 
Rivers, together with most buckbrush patches in the Bad Lands of western 
North Dakota, were heavily infested in 1939, One range land area north 
of Miles City, Mont*, and extending west to the Musselshell River, aver- 
aged about 50 grasshoppers per square yard over 4,000 square miles. 
Between Williston and Walters Perry, N, Dale, , along the Missouri River 
bottom, popu.lations of M, mexicanus ranged from 50 to 500 per square 
yard. The Bad Lands along the Little Missouri between North Roosevelt 
Park and Medora, N, Dak,,, flats in the river bottom and benches above the 
flats averaged 75 to 150 per square yard. Leading down to the Little 
Missouri River are long, dry creeks and innumerable steep draws from one 
to several miles long. Each draw or coulee had its quota of hoppers, 
averaging from 50 .to - 150 per square yard. 
