58 American Midland Naturalist Monograph No. 1 



in the female, 0.60 tc 0.69, and in the male, 0.45 to 0.525. Much longer than 

 in p<xrk.er\. 



Folds. — Coxal and supracoxal folds present. 



Grooves. — Dorso-ventral groove present and visible on the dorsal surface 

 at the sides. Preanal, transverse postanal and median postanal grooves pro- 

 nounced. 



Sexual opening. — At the level of the intervals between coxae I and II. 



Eyes. — Absent. 



Anus. — In an oval pattern. 



LARVA 



Oval, slightly wider behind, mouth parts visible from above. Integument 

 thin, striated and with the sparse hairs in a symmetrical arrangement. Length, 

 not including mouth parts, 0.84, width, 0.57. 



Hypostome. — Long, sides nearly parallel, and rounded apically; denticles 

 2 /o occupying about the apical two-fifths of the length, and with the lateral 

 denticles larger. Posthypostomal hairs long. Length of hypostome about 0.135. 



HOSTS 



O. turicata attacks a wide variety of hosts, including reptiles, birds, and 

 mammals. Specimens have been collected from rattlesnakes, turtles, burrowing 

 owls, ground squirrels, prairie dogs, kangaroo rats, woodrats, rabbits, pigs, 

 cattle, horses, and man. In Kansas, Oklahoma, and Texas we have found it 

 in large numbers in rodent burrows and burrows used by burrowing owls, 

 Speotyto cunicularia. Davis (1936) reported the collection of eleven hundred 

 and ninety-seven specimens from a single sand hole which contained 1 1 terra- 

 pins, Terrapene ornata, in Clark County, Kansas. The U. S. Bureau of 

 Animal Industry has several records from pigs and from sinks frequented by 

 pigs in Florida and according to Hoffman (1930) there have been many 

 serious outbreaks of plagues among pigs in the central part of Mexico where 

 enormous quantities of the species have been found on the ground in pig sties. 

 All stages attack man readily. According to our experience the bite is pain- 

 less but is followed in a few hours by intense local irritation and swelling. 

 Subcutaneous nodules often form which, accompanied by occasional itching, 

 may persist for months. However, in Mexico, Hoffman (1930) states that 

 the bite is painful and often followed by serious secondary consequences, 

 characterized by the formation of gangrene in the skin. This latter effect he 

 attributes to the filthy habitat of the species, i.e., pig sties, etc. 



This species is the only known vector of human relapsing fever in portions 

 of Kansas, Oklahoma, Texas, and possibly other areas in the Southwestern 

 United States. Hoffman believes that O. turicata has little to do with the 

 transmission of relapsing fever in Mexico since no cases have been found in 

 the region where this tick occurs. 



distribution 



The localities for which there are definite records of the collection of O. 

 turicata are shown in figure 24. In the United States the species is known 

 from Utah, Colorado, Kansas, Oklahoma. Texas, New Mexico, Arizona, 



