BEPORT OF THE SECRETARY. 115 



these were intercepted and destroyed, but the presence of 20 new 

 pests whose capacities for crop destruction were undoubtedly very 

 great affords the strongest possible argument for the passage of a 

 National plant quarantine and inspection law. On three different oc- 

 casions during the past year the gipsy moth has come in on imported 

 stock consigned to different localities in the country. 



OTHER WORK. 



Other important operations carried on by the bureau during the 

 year may be briefly mentioned. The work against the cotton boll 

 weevil has been continued. The weevil extended its range during the 

 year into the State of Alabama. On the other hand, it was entirely 

 absent from certain regions in northern Texas, where it was present 

 last year. It also did no noticeable damage in Oklahoma. Studies of 

 the parasites of the weevil were continued, and Texas parasites were 

 introduced at two points in Louisiana, The work on tobacco insects 

 was also continued, A notable discovery was made with regard to 

 the so-called tobacco wireworm which indicates that it can be con- 

 trolled by cultural means. It feeds naturally upon certain weeds 

 and these weeds are eliminated by rotation of crops. In the 

 study of sugar-cane insects new points of importance were as- 

 certained. The Argentine ant and the cotton red spider work was 

 continued. Demonstration work in the deciduous fruit regions in 

 California, with remedies for the pear thrips, was carried on with 

 excellent success, indicating that in prune orchards the yield from an 

 acre treated according to the directions of the bureau reached a value 

 of $367,93, where an untreated acre yielded only $6.65, Work upon 

 the codling moth, plum curculio, Hessian fly, and the jointworm has 

 been continued with success, and important advances have been made 

 in methods of fighting insects affecting vegetable crops and stored 

 products. Information on the subject of the house fly as a carrier of 

 typhoid fever and on malarial mosquitoes has been published, and 

 the study of the tick which transmits Rocky Mountain spotted fever 

 has been completed. Further studies upon the cattle tick have been 

 made, and an investigation of the possible influence of certain insects 

 in the carriage of pellagra has been begun. The work on bee diseases 

 has been continued. 



BUREAU OF BIOLOGICAL SURVEY. 

 RATS AND THE PLAGUE. 



The rat is one of the most destructive mammals known, and the 

 vast losses it annually causes in the United States call for increased 

 efforts to reduce its numbers and to exterminate it wherever possible. 

 Moreover, the continuance of the bubonic plague in foreign countries. 



