204 - 
ILLINOIS 
This is the first year in which collections were made in this State 
during the adult survey. The original natural vegetation areas of Illinois 
were the tail-grass prairies and the oak- hickory southern hardwood forest 
along the- rivers and streams. As in Iowa, and other tail-grass prairie 
Stales, the original vegetation areas have "been changed hy the introduction 
of agriculture and attendant changes in topography and flora. As a rule, 
grasshoppers do not flourish to the extent they do out West in the Great 
Plains States. There were 5,539 specimens collected, representing some 
24 species in 8 different environments. Uelanoplus femur -rub rum was the 
most important species in all the environments, with the exception of 
cornfields and waste places. In the latter, M. diff erentialis was dominant. 
For the entire State collection, If. f emur-ruhrum was first in numbers at 
21 percent; LI. diff erentialis second at 9 percent; and M. mexicanus third 
at 6 percent. 
A small percentage of hatch had occurred in the southern part of 
the State hy the first of May. Frequent heavy rains retarded hatching 
and reduced populations so that damage was negligible in almost every 
county. Some late damage occurred from adults. There are two areas of 
infestation; one in the northern tier of counties and one in the mid- 
western pent of the State. Normal rainfall conditions will probably hold 
these in check. 
