MONTANA 
This is tlic fifth year in which collections wore nade in typical en- 
vironments in Montana during the adult survey. There were 11,129 specimens, 
representing 4-5 different species, collected in 9 environments. Because of 
the great flights in July 1938, of Molanoplus mexicanus into eastern Montana, 
this species was "by far the most numerous of all. The year 1938 can he con- 
sidered as the year of its greatest majority in all environments during the 
5 years of collections. It formed 63 percent of the total specimens taken 
in the .State, 46 percent in alfalfa, 83 percent in idle land, 66 percent in 
reverted land, 85 percent in sugar heets, 82 percent in small grain, 54 per- 
cent in range land, and 94 percent in corn, where it is not often a pest, 
M. femur- ruhrum , M. hivittatus , and packardii were the other important 
species. Camnula pellucida and Aul ocara elliotti were of still lesser im- 
portance. The most interesting species has been M, mexicanus , because of its 
spectacular flights and the interest shown in its infestations in range and 
idle land. In the recent history the open range land has not harbored serious 
outbreaks of this species. The drought of 1934 drove M. mexicanus to the open 
range and it was the dominant species that year in the collections from these 
places. In the extreme eastern part of the State, it made up 45 percent of 
the grasshoppers found in the range. This seemed to have had little effect 
on the grasshopper fauna the following year, 1935, for U, mexicanus occupied 
fifth place in the range-land collections, forming’ 9 percent of such collec- 
tions. In both the 1936 and 1937 collections it was third in number at 10 
percent. Owing to the flights in 1938, it was in first place again, at 54 
percent of the total specimens collected on the range land. In 1934 M. 
bivittatus was greatly reduced by the drought throughout the State. It has 
increased in numbers proportionately, until in 1938 it held third place, 
along with M. packardii . On the range land, M. infantili s seems to have 
equaled or outnumbered Aul ocara, elliotti and Ageneotettix do o rum which were 
the dominant species in 1937. 
Hatching of M. mexicanus began the first week of May and, because of 
rainy weather, was retarded and prolonged throughout June. The fall survey 
of 1937 indicated a general reduction in the grasshopper potential in the 
eastern half of the State. The nymphal surveys showed light populations of 
nymphs of from 0 to 5 per square yard in many open fields, with heavier 
populations of from 20 to 150 concentrated along field margins and even 
1,000 per square yard in 1 place. These figures did not begin to approach 
the enormous numbers occurring in north-central South Dakota and parts of 
North Dakota,. Beginning on July 1 and continuing throughout the period of 
the major flights into eastern Montana from North and South Dakota, popule,- 
tion counts ran from 20 to 200 per square yard in many places. Heavy egg 
deposition occurred where these flights terminated. As in eastern Wyoming, 
a steadily decreasing grasshopper potential from 1934 has been changed in 
1 season to an infestation of major importance. 
