In all of the Black Hills area of South Dakota and Wyoming every 
mountain-hay meadow, pasture, and cropped field was severely infested 
with M. mexicanus hatching from eggs deposited hy grasshoppers in flight. 
Populations ran as high as 5,000 per square yard and one observation 
showed all the huckhrush ( Svmuhori caruo s ) in 3 acres destroyed doxim to 
the roots by the grasshoppers, which had defoliated and decorticated it. 
In eastern Wyoming and western Nebraska heavy infestations 
occurred in most of the favorable crop fields and especially in strip- 
farmed and stubbled-in grainfields. 
In the northern Red River Valley, severe infestations of 
M. mexicanus occurred in pastures, waste areas, stump land, alfalfa 
fields, and other habitats. Prom these places they migrated into the 
crops. In south-central and southeastern South Dakota, southwestern 
Minnesota, and northeastern Nebraska severe local infestations of 
Melano-olus bivittatus Say, M. differentialis Thos, M. mexicanus . and 
M , f emTor-rub rum . Dog . occurred. In the Eamill, S. Dak,, district, the cen- 
ter of the disastrous 1931 outbreak, M, bivittatus hatched out in corn 
and sorghum stubble planted to small grain. Populations of 300 per 
square yard were not uncommon. In the buffalo and grama grass sod clumps 
along the edges of coulees, egg pods of M. differentialis averaged as 
high as 12 per square foot the first half of May at the same places where 
populations of M, bivittatus nymphs averaged 350 per square yard. 
The area infested by Diasosteira longiuennis Thos, included parts 
of 5 States; namely, southeastern Colorado, southwestern Kansas, Pan- 
handle of Oklahoma, Panhandle of Texas, and northeastern New Mexico, 
with the major infestations in Colorado, New Mexico, and Texas. In 
these 3 States, during the 1939 spring egg surveys, a total of 75 egg 
beds were examined for eggs. The egg beds ranged in size from l/2 acre 
to 200 acres, with an average of 15 acres per bed. The average egg-pod 
population ranged from 0.7 pod to 20 pods per square foot with an aver- 
age of 5,^ pods per square foot for the 75 beds. 
Pirst-instar nymphs upon hatching numbered as high as 2,000 per 
square yard, with an average of 500, In many instances, within a week 
or 10 days after hatching, nymphs occupied 10 times the area of the egg 
bed. In Colorado it was estimated tha.t the last-instar nymphs alto- 
gether covered 5 times as much area as the original egg beds and in New 
Mexico 10 times as much. 
The population of M. mexicanus in the most severely infested 
areas of eastern Montana and western North Dakota were reduced to non- 
economic numbers in much of the area. This was accomplished largely by 
flights out of the area, although control measures may have reduced 
populations about 10 percent. In western Nebraska, western South 
Dakota and eastern Wyoming, damage to small grain \yas reduced 50 percent 
by baiting. Infestations were reduced by flights out of the area and 
control measures until only local infestations remained. In the 
D . lo neiu enni s area populations of this species were reduced largely by 
