22 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1951 
Although intensive airplane baiting for 2 years in Wyoming had 
practically eliminated bait-eating range grasshoppers as an economic 
factor over extensive areas, there still remained in L950 from 2,750,000 
to 3,000,000 acres of heavily infested private range lands. To reduce 
infestations to Qoneconomic importance a large-scale cooperative pro- 
gram was set up. The Wyoming Legislature, at a special -('--ion in 
the spring of L950, provided $750,000 for the work, which sum was to 
be matched by the Federal Government. In this cooperative work 
approximately 2,462,000 acres of range lands were baited by airplane 
in 16 Wyoming counties at an average cost of 57 cents an acre. Two 
Bureau and 11 contract aircraft operated from 62 airstrips and air- 
port-. All but 4.0 of the landing fields were specially built by coun- 
ties and ranchers. The baiting operations saved large quantities of 
forage. So far as known, no grasshopper migrat ions originated from 
treated area-. Grasshopper numbers were greatly reduced in heavily 
infested areas. At the close of the L950 season there -till remained 
more than 800,000 infested acre-, principally with bait-resistant 
species. 
Arizona and Federal funds in equal amounts were -pent to treat 
about 15,000 acres of a threatening infestation in southeastern Ari- 
zona range lands. Because of the high proportion of a bait-resistant 
species, the work was done by aerial application of an aldrin-oil solu- 
tion spray at the rate of 2 ounces of aldrin in enough kerosene to make 
1 gallon an acre. Seven cont ract airplane- -prayed slight ly more than 
43,000 acres, at an average cost of 77 cent- an acre. 
Farm crop- within an area can be protected from grasshoppers by 
a well-planned program of air or ground >prayini_ r with aldrin, 
chlordane, or toxaphene. To be effective, the program must provide 
for treatment throughout the season of all sources of infestat ion within 
the area to he protected. In L950 infestations were virtually eradi- 
cated on L,100 acre- of -mall grains and flax in Bottineau County, 
\. Dak., by spray application- of aldrin and chlordane. Previous 
work' in South Dakota and Nebraska had -how n that grasshopper in- 
festat ion- in al falfa and adjacent fields, field margins, and waste areas 
in a -olid block of farm land could he reduced 90 to LOO percent in a 
single season by the use of toxaphene or chlordane sprays. The reduc- 
tion persisted for at least - years. It i- believed that only limited 
insecticide treatments of small local infestations within the originally 
treated area will he necessary for some time to maintain adequate crop 
protection. It is likely that this method of grasshopper control will 
he used increasingly by fanner-. 
Severe infestation* expected in 7 r A77 
Adult grasshopper surveys were conducted in 889 counties in 22 
Si ate- : egg surveys were made in »'.:;7 counties in 1 1 State-. The 1950 
late -niiiiiier and fall -nrvey- indicated that with normal weather in 
1951, grasshopper infestations could he expected to be severe and dam- 
aging to both crop- and range land forage in many sections of the 
western half of the United State-, despite the extensive control work 
done in L950. Range land infestations again constituted the major 
threat in several Stale-. In Wyoming the infested area was further 
reduced hv the 1950 program, hut there were -till threatening infesta- 
tions on range land. Threatening to \ery severe infestations an i i 
