BUREAU OF ENTOMOLOGY. 537 



oughly covered. It is hoped to follow this bulletin on the active 

 remedial work with others trealino^ of malaria and the malarial mos- 

 quitoes, of yellow fever and the yellow-fever mosquito, of the gen- 

 eral habits of mosquitoes, and still another on the classification of 

 mosquitoes. 



THE HOUSE FLY. 



The work on the house fly has been continued, and the crusade 

 against this disease-bearing species has been assisted in every possible 

 way. The name, suggested by the writer, of " typhoid fly " as a sub- 

 stitute for the name " house fly " is becoming generally adopted. 

 Conservative physicians a])pear to be more and moie convinced of 

 the dangerous qualities of this insect. The American Civic Asso- 

 ciation has taken up the crusade, and boards of health and citizens' 

 improvement societies all over the United States are paying great 

 attention to the destruction of this species. The crusade has ex- 

 tended into other countries, and the Bureau congratulates itself on 

 having at last aroused strong public opinion in a ver}'^ important 

 sanitary matter. 



WORK ON TICKS. 



The work of the Bureau on the important injurious ticks of the 

 country has been conducted under the direction of i\Ir. "\Y. D. Hunter 

 by Mr. F. C. Bishopp. These investigations have consisted of two 

 primary lines of work : First, with the tick which transmits splenetic 

 lever of cattle, and, second, with the species Dermacentor venustus^ 

 which transmits spotted fever of human beings in some of the Rocky 

 IMountain States, 



The work on the cattle tick consisted of two parts, one dealing 

 with the continuation of life-history studies and the other with prac- 

 tical demonstrations of methods of control for the benefit of ranch- 

 men. The great diversity of climatic and other conditions in the 

 area infested by the cattle tick causes it to be exceedingly imj^ortant 

 to ascertain the local variation in the development and life history 

 of the pest. Moreover, such definite information must be available 

 for the practical work of eradication which has been undertaken by 

 the Bureau of Animal Industry and can only be obtained by means 

 of experiments running through several years. Consequent!}'-, the 

 experiments to determine the length of time the seed ticks can sur- 

 vive without hosts were continued. Special efforts were made to 

 secure records from a number of localities. In this work the Ten- 

 nessee experiment station cooperated in a very helpful manner. 



On account of the general popular idea that sulphur taken into the 

 system of cattle either by feeding or drinking of water impregnated 

 with the substance will cause the ticks to drop off, a special experi- 

 ment was arranged to furnish exact information. A fence was built 

 around a well in southern Texas, the water from which is very heav- 

 ily impregnated with sulj)hur. Small droves of cattle heavily in- 

 fested with ticks were placed in this inclosure from time to time and 

 observations were made regarding the action of the ticks. The 

 results were entirely negative. The well used in the experiment rep- 

 resents extreme conditions as regards sulphur content. The results, 

 therefore, are of very definite value and should prevent the useless 

 expenditure of money for sulphur on the part of cattle owners. 



