baiting operations to noneconomic proportions in Texas, to about 250 
acres of egg beds in Uew Mexico, and to 1,910 acres of egg beds in 
Colorado, 
Fall Egg Survey in 1959 
The 1939 fall egg survey showed that areas of severe infestation 
had shifted considerably in the Melanoplus mexicanus area. In Montana 
the north-central counties were the most heavily infested. This was , 
the area where the 1939 flights from eastern Montana terminated. In 
eastern Montana, from light to subnormal egg populations were fOTind in 
areas most heavily infested during 1939, A large portion of eastern 
North Dakota was severely infested with M, mexicanus and M. bivittatus , 
while western North Dakota was comparatively lightly infested. 
The eastern half and two-thirds of the southern half of South 
Dakota was also infested. From the Dakotas the infestation extended into 
the western third of Minnesota and the extreme northwestern part of 
lovra, A large part of this whole area in these three States lies within 
the 20-inch rainfall belt. These infestations were a local build-up of 
M. differentialis , M. bivittatus . and M. mexicanus in the southern 
part. In the northern part it was largely M. mexicanus , 
A spotted, severely infested area lay diagonally from eastern 
Nebraska across western Kansas, extending into eastern Colorado and 
the Panhandles of Oklahoma and Texas. In Kansas and parts of eastern 
Colorado Aeoloulus turnbullii Thoe. was of recent economic importance. 
It proved a damaging species in 1938 but it is still an undetermined fac- 
tor in the grasshopper outbreaks, M. mexicanus has become of increasing 
importance in both western Oklahoma Panhandle and northern Texas Pan- 
handle, This is also true of parts of eastern Colorado, especially the 
northeastern part. 
Infestations in western Nebraska were -down, but not to the ex- 
tent they*were down in eastern Wyoming and western South Dakota, In 
Nevada and Utah there were severe local infestations, but for Idaho, 
V/ashington, and Oregon, there was a very small grasshopper problem. This 
was also true for most of Arizona, New Mexico, Oklahoma, Arkansas, 
Missouri, Illinois, Iowa, and Wisconsin, The northern half of the 
Southern Peninsula of Michigan had some severe local infestations. In 
California the Imperial Valley showed a severe infestation of M. mexicanus . 
There were also local spots of infestations of different species 
scattered in their usual areas. 
Infestations of Dissosteira longinennis were about completely 
wiped out in Texas, There were two small areas in New Mexico and about 
100 small egg beds in the southeastern quarter of Colorado. 
For the entire area, severe infestations were limited to about 
seven or eight States at most, many of which are in heavily cropped areas. 
For this reason, they were of greater economic importance but probably 
provided a better opportunity for organized control. 
