246 Phylum Arthropoda 



moisture may escape. It is essential to keep the cells moist. In some 

 cases a piece of blotting paper on the cell-floor will be satisfactory. The 

 animals may be fed on bits of moss, lichens, cheese mold, or on soft, 

 moist, dead wood. The cells must be inspected daily to regulate the 

 moisture content and the growth of molds. 



References 

 Family Tyroglyphidae 



For culture, including that of Tyroglyphns linteri, see p. 266. 



Family 



IXODIDAE 



TICK REARING METHODS WITH SPECIAL REFERENCE 



TO THE ROCKY MOUNTAIN WOOD TICK, 



DERMACENTOR ANDERSONI STILES* 



Glen M. Kohls, United States Public Health Service 



TICKS belong to the order Acarina, superfamily Ixodoidea, which 

 is composed of the families Ixodidae and Argasidae. 

 Tick rearing is an involved process because of complicated life cycles, 

 the blood feeding habit which necessitates the use of host animals, and 

 the different environmental requirements of different species during 

 aestivation and hibernation and other periods when not on host animals. 

 Rearing methods applicable to specific problems have been developed 

 by different groups of investigators, but lack of space makes it necessary 

 to limit this article to those methods and equipment now in use at the 

 Rocky Mountain Laboratory for the rearing of the Rocky Mountain 

 wood tick, Dermacentor andersoni. These methods have been developed 

 by several investigators over a considerable period of years in connection 

 with study of tick-borne diseases of the United States, and especially in 

 relation to that of Rocky Mountain spotted fever and the manufacture 

 of spotted fever vaccine. This vaccine is prepared from the tissues of 

 infected adult D. andersoni and necessitates the rearing of this species 

 in large numbers. The methods described are applicable in general to 

 other species of ixodid ticks. 



D. andersoni is a three host tick, the adults of which are active in 

 nature from the latter part of March to about July 1st. They are 

 usually found on livestock and the larger game animals, and attach 

 readily to man. When host contact is made the ticks attach and feed to 

 repletion in 8 to 14 days, copulation occurring while the females are still 

 attached. The latter increase enormously in size due to the blood meal, 

 leave the host and, after 2 to 4 weeks, deposit 4,000 to 7,000 eggs in a 



♦Contribution from the Rocky Mountain Laboratory, United States Public Health Serv- 

 ice, Hamilton, Montana. 



