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American Midland Naturalist Monograph No. 1 



O. amblus resembles O. capensis from Africa, but the former is readily 

 separated by several characters including the longer legs, the more numerous 

 and more pointed denticles of the hypostome and in having the mammillae 

 more nearly hemispherical on top and more regular at their bases. 



hosts and distribution 



This species is known from guano islands off the coast of Peru, South 

 America. Chamberlin (1920) states: "Dr. Murphy notes that these ticks are 

 a type 'extremely abundant on all the Peruvian guano islands. They live in 

 the soil and the guano.' " Larval specimens were taken from the plumage of an 

 adult penguin (Spheniscus hwnboldti) . 



Murphy (1925), p. 246, states: 



Moreover, the ticks do not confine their attacks to the birds, but at times bite the 

 skin of the native Indian laborers, usually upon the feet or legs, producing sores which 

 are apt to be persistently troublesome. 



Mr. Murphy in the same book (p. 245) states: 



The most significant fact concerning the ground spiders is that they appear to subsist 

 largely upon the native ticks, which are blood-sucking parasites of the birds. The spiders' 

 dens are sometimes filled with shriveled remains of the ticks, for, since spiders eat only 

 the body juices of their quarry, they take a remarkably heavy toll. Thus they become 

 the chief natural agency in restricting the numbers of an important enemy of the guano 

 birds. 



While this species has not been collected in nature in North America, it 

 is reported as very abundant on the guano islands and may be readily intro- 

 duced with shipments of bird guano. In a recent letter Bequaert states: "It 

 has been found recently in a port of the United States, in a shipment of 

 guano." 



^^§? 



Fig. 45. Ornithodoros amblus Chamberlin. A, Hypostome of female. B, Leg I of 

 female. C, Leg IV of female. 



