The effect of the weather on insect abundance nay ho seen in the case of 
grasshoppers. The cool, rainy weather of May retarded hatching, hut pernitted 
b , profusion of range grasses. In June the weather was warm and drw in western 
North Dakota and northwestern South Dakota, favoring the development of grass- 
hoppers. The grasshoppers, having abundant food, rapidly reached maturity and 
the grasses were eaten down and dried up by the dry weather, resulting in heavy 
flights of grasshoppers from this area into eastern Montana, the Rod River 
Valley, and Canada. 
In its effect upon the chinch bug the season of 1938 almost duplicated 
that of 1937 . The insect overwintered successfully but the wet, cool weather in 
the spring w as detrimental to it, and in the fall the dry, warm weather favored 
increased populations and hibernating conditions. 
GRASSHOPPERS 
The greatest damage occurred in the northern Great Plains States in and 
near the overlapping zones of short and long grass and where the annual rainfall 
for the last 2 years has amounted to less than 20 inches. Repeated crop failures 
in these dry areas resulted in large acreages in reverted and idle lands. These 
areas bred tremendous numbers of Melanoplu s mexicanus Sauss, and resulted in 
destruction of crops through migration of nymphs to adjoining crops and through 
flights of adult grasshoppers to distant fields. 
In the southwestern portion of the Great Plains area, including the south- 
eastern counties of Colorado, the northeastern counties of N )W Mexico, and Pan- 
handle counties of Texas which adjoin New Mexico, Dissoteira longipennis Thos. 
occurred in numbers large enough to produce flights late in the season. Very 
large numbers of grasshopper eggs wore deposited in the fall of 1937 and hatch- 
ing in the spring spread over a long period of time,- The value of the crops lost 
amounted to $o3, 8^1,000 and it is estimated that $176,442,000 worth of crops 
were protected by control measures. The most serious damage occurred in North 
Dakota, South Dakota, .and Nebraska, North Dakota reporting over $24,000,000 
damage and South Dakota and Nebraska each reporting ov<->r $11,000,000 damage, 
Kansas and Montana each reported over $6,000,000 damage, Wisconsin reported over 
$4,000,000, Oklahoma, Missouri, and Colorado each -reported over $2,000,000 damage, 
while Iowa, Minnesota, and'Tekas eadh' reported ' over l$r,'0'00, 000 damage. Very 
severe damage also occurred in Arizona, California, Idaho, Illinois* Michigan, 
Nevada., New Mexico, Oregon, Utah, Washington, and Wyoming. 
A nap showing the results of the fall egg survey is included, 
EUROPEAN CORN BORER 
Although general scouting to determine the dispersion of the corn borer was 
not conducted in 1938, observations made by. State personnel in Wisconsin, 
Indiana, and Virginia indicate that only a slight increase occurred in the total 
infested territory. New infestations were observed in two counties in Wisconsin 
and two in Virginia. No new county infestations were found in Indiana, although 
infestations were recorded in 1938 in a number of townships not previously report- 
ed as infested, within infested counties, A single specimen of the corn borer 
collected at Arlington, Va, f indicates that additional dispersion had occurred in 
the Eastern States, although abundance levels are too low to determine its 
approximate extent, except by intensive scouting. In the Lake States the general 
