importa.nce here than in the irrigated sections. On the range land 
Dissosteira longipennis has been the most destructive sjjecies. 
In general, during the last 6 years, the greatest numbers of the 
predominant species occurred during the period from 1936 to 1939, inclusive. 
A sharp decrease in numbers in all habitats occurred in 1940 and a sharp 
rise, especially of Melanoplus mexicanus , in 1941. This rise was due 
largely to the development of a second generation of this species, to 
flights out of western Kansas during the summer Of that year, and to the 
fact that the records are based on limited areas of heavier than average 
infestation. Aeoloplus turnbullii reached a peak of abundance in grasslands 
and idle land in 1938 and has declined since. A great reduction occurred 
in June 1941, following heavy rains. On June 28 from 1 to 5, fourth- and 
fifth-instar specimens per each Bussian-thistle were found dead and cling- 
ing to the plants ih the manner typical of grasshoppers attacked by fungus. 
The highest record was 12 per square yard dead, but other species were not 
noticeably affected at this time. 
KANSAS 
For the purpose of these studies the State of Kansas was divided 
at the 98th meridian into eastern and western parts, with corn the major 
crop in the east and winter wheat in the west. Alfalfa is of greater im- 
portance in the east than in the west, where pasture and idle lands make 
up the greater part of the farmed areas. Because of the infrequency of 
surveys in the eastern section of the State, the data in the tables are 
limited to 'those gathered in the more frequent a.nd uniform surveys made 
in the western section. 
Although no adults were collected in the western part in 1936, this 
wa s a year of severe damage to corn in the eastern part, where Melanoplus 
different ialis was the most important species. From 1937 to 1939, inclusive, 
there was a marked increase in numbers of M. mexicanus in the western part 
of the State. In 1940 there was a sharp decrease of all species and as marked 
an increase in 1941. This increase was confined largely to the western third 
of the State, as the eastern half has had relatively low populations since 
1936. The western third of Kansas is an area marked by a second generation 
of M. mexicanus , which, in 1941, hatched about August 1. 
In 1938 and 1939, Aeoloplus turnbullii reached its greatest abund- 
ance, but dropped to low numbers in 1940 and 1941. This species is limited 
largely to the western third of the State. 
MONTANA 
In Montana the major crops are hard spring wheat and other small 
grains. Idle land and range land make up most of the rest of the agricul- 
tural areas* 'Weedy stubble fields and' idle land are the chief source of 
grasshopper infestation. Corn, sorghum, and alfalfa fields are not major 
sources of infestation. In all past outbreak's Melanoplus mexicanus has 
been by far the dominant species, forming from 75 percent of the population 
on the range, although its chief habitats have been small-grain stubble 
and idle land. In irrigated sections M. bivittatus has at times been 
