404 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 3 3 



being the mice, ground squirrels, and pine squirrels, while the adults 

 feed mainly upon the larger wild and domestic animals. 



Winter is spent in the nymphal or adult stages. The adults appear 

 very early in the spring, often while snow is yet on the ground, and 

 they decline very markedly in numbers during midsummer, relatively 

 few of them being abroad after the 1st of August. The seed ticks 

 usually do not live more than 2 months, but often nymphs survive 

 for nearly a year and apparently the adults often live for more than 

 a year and a half. The entire life cycle usually requires from 2 to 3 

 years. 



The habits of the ticks make their control very difficult. A num- 

 ber of years ago the Bureau of Entomology and the Public 

 Health Service in cooperation with the Montana Board of En- 

 tomology attempted to control this pest in the Bitter Root Valley of 

 Montana where spotted fever was extremely virulent. The control 

 efforts were directed against the ground squirrel and other small wild 

 animal hosts, and special attention was given to the systematic 

 dipping of the horses, cattle, and dogs during the spring months for 

 the purpose of destroying the adult ticks. While the tick popula- 

 tion was undoubtedly decreased by these procedures it did not elimi- 

 nate the ticks from any given area. In addition to these control 

 steps it is important to avoid being bitten by these ticks, and par- 

 ticularly not to allow ticks to remain attached more than a few 

 hours at most. As has been pointed out short periods of feeding are 

 not likely to induce the disease. 



The Montana Board of Entomology, and subsequently the United 

 States Public Health Service, have done considerable work with the 

 propagation and liberation of a minute wasplike insect which attacks 

 and destroys the nymphal stage of certain ticks. While the results 

 thus far have not been especially encouraging, the importance of 

 this tick as a transmitter of disease would seem to warrant the taking 

 of any steps likely to reduce the number of ticks in a given locality. 



THE BROWN DOG TICK 



For a number of years many of the dogs in certain parts of Texas 

 and Florida have been greatly annoyed by the attacks of the brown 

 dog tick, Rhipicephalus sa7iguineus. More recently this tick has 

 been spread, largely through the movement of dogs, from infested 

 areas into many parts of the United States. While normally it 

 thrives only in the tropics and sub-tropics, it has been found that 

 where introduced into northern latitudes on dogs which are kept 

 more or less constantly indoors the tick will live and multiply at 

 least for a time in any part of the United States. The species is 

 not only an annoying pest of dogs but is also a troublesome house- 



