338 ANNUAL EEPORTS OF DEPARTMENT OF AGRICULTURE. 



RODENT PESTS. 



Baclced by the sustained interest and strong financial support of 

 farmers and stockmen, the work of eradicating destructive rodents 

 on Federal, State, and pri^^ate lands has progressed with increased 

 vigor. The concerted drives conducted under the leadership of 

 bureau specialists have proved of such definite value that this ad- 

 vance has been made in spite of the general tendency toward re- 

 trenchment due to financial depression. In fact, it appears that 

 this state of affairs has served to accentuate the importance of elimi- 

 nating losses in, production and waste of agricultural products due 

 to rodent pests, since this has come in many places to be recognized 

 as a factor which often determines profit or loss on the year's efforts. 

 The correlation of Federal, State, and local agencies into an effective 

 cooperating working force has been continued through the States 

 Relations Service with the State extension organizations, including 

 the county agricultural agents and State and county farm bureaus. 

 Stlite departments of agriculture have participated on an increased 

 scale through the organization of pest districts and enforcement of 

 State laws relative to clearing rodent-infested lands. Many other 

 agricultural, horticultural, and live-stock organizations have also 

 taken active part. Officials of the Forest Service and of the Office 

 of Indian Affairs and the Reclamation Service continued to cooper- 

 ate in campaigns involving Federal lands under their control. 



Where features affecting community health Avere associated with 

 the distinctly economic problems, as in bubonic and pneumonic 

 plagues, Rocky Mountain spotted fever, and kindred disease-pro- 

 (hicing agencies disseminated by rodents, the bureau continued to 

 cooperate with the United States Pu1)lic Health Service, of the Treas- 

 ury Department, and with State, county, and municipal health or- 

 ganizations. Such cooperation is essential to complete success when 

 rodents infest both the cities and villages and the rural sections. 



Conspicuous damage to crops and range grasses by the larger 

 native rodents, as prairie dogs, ground squirrels, pocket gophers, 

 and jack rabbits, first led to the large-scale organization of this work 

 in the Western States. The marked benefits resulting from control 

 measures employed against these rodents led to more careful and 

 detailed observation and the recognition of the widespread and im- 

 ):)ortant damage by the numerous smaller but abundant native ro- 

 dents. 



PRAIBIE DOGS AND GKOtTND SQUIRRELS. 



In the organized campaigns against prairie dogs and ground 

 squirrels, 17,678,041 acres of Federal and private lands were given 

 a first treatment with poisoned baits during the year, and follow-up 

 work to complete eradication was done on 8,004,469 acres. This 

 makes a total of 10,164,899 acres of Federal lands and 93,345,400 

 acres of State and private lands which have been treated, since 1916 

 and largel}' cleared of these rodents in the following States : Arizona, 

 California, Colorado, Idaho, Kansas. Montana, Nebraska, Nevada. 

 New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, 

 Utah, Washington, and Wyoming. 



The bureau assumes the cost of operation on Federal lands, State 

 officials on State lands, and farmers and stockmen on their own hold- 



