348 
MTAxIA 
This i? the sixth year in which collections hare "been made in 
Montana during ^the surrey. There were 10,542 specimens representing 
59 species collected In 11 different major enrironments, Melanoplus 
mexicanus was the dominant species in 10 out of the 11 habitats and 
formed 46 percent of the total number of specimens collected. Ageneotettix 
deorum was second in total numbers collected and first in numbers on the 
range- l^d.. -Outside of the open range, no other species compared Airith 
M. mexicanus in importance. In 1938 mexicanus formed 54 percent of 
the total specimens collected in the range land, but in 1939 it made up 
only 17 percent of the total. The comparatire percentages in the fol- 
lowing table sho\iT the decrease in relatire abundance of this species from 
1938 to 1939. 
Table 12 — M. mexicanus. percentage of total number of specimens 
collected in the major habitats 
Habitat 
Percentage; of 
1938 
total collected 
1939 
Small grain — - 4 -- 
82 
73 
Idle land- — : 
83 
67 
Roadside ^ 
62 
54 
Range land 
54 
17 
Alfalfa--; 
46 
59 
Total for State r 
63 
46 
These data indicate a falling off of the relative abundance Of ‘ 
M. mexicanus for the State as a whole, although it is a seriops problem' 
in 7 north-central counties. At least 90 percent of the severe infestations 
are in small-grain stubble and idle land.- In Kill County there was an 
average of 7.09 pods per square foot recorded in 915 field samples taken 
in 109 fields. This is the heaviest infestation on record since the present 
annual grasshopper surveys were established in 1931, The infestations in 
the 7 north-central counties result from flights of M. mexicanus origi- 
nating in the eastern part of the State in July and August. 
