Long knovn as the Argentine horse tick because the source of 

 the original specimen was stated to be Valparaiso, this tick has 

 never been reported ft-om South America. Why Valparaiso has been 

 referred to Argentina and not to Chile is uncertain. As early 

 as 1907, Donitz questioned the South American origin of this 

 species, remar}p that were overlooked by most subsequent writers. 

 According to Donitz (I9IOB), Winthem was a Hamburg dealer (pre- 

 sumably in zoological specimens _ HH) . 



1 q?AA^^^^?*^^ ^^^^ "°* discovered in M. winthemi by Covdry (1925C, 



Schulze (1938A) mentioned this species in his study of adult 

 development within nymphs and in his 1943B study. Jakob (1924,) 

 included M. winthemi in his study of tick genera as have all 

 authors who have discussed this subject. Because of its re- 

 markable appearaiwe, this species has been widely illustrated 

 and discussed, usually largely incorrectly. 



The first reference to this tick in South Al'rican literature 

 (Theiler, correspondence) is that of Orpen (I904.): "It is com. 

 monly believed here that there are no ticks in the Barkly East 

 district, or only such as are brought in by transport cattle 

 during the Summer and that ticks will not survive the severity 

 of our winter hosts. I may state that last Winter I found many 

 ticks upon our veld fed horses and that this winter they are 

 worse, in a troop of about seventy mares and foals, many animals 

 are fairly covered with ticks. We have had severe frosts since 

 the beginning of April and the mountains are white with snow. 

 This would lead one to conclude that given the protection and 

 the warmth of an animal's body these ticks will live through any 

 New England (Barkly East district) winter, (it is noticeable 

 that the variety found on our horses remain upon them when molt- 

 ing)". 



The original description of the genus, translated from Ger- 

 man, is as follows: Margaropus gen. nov. Body slender, longer 

 than wide, sides slightly sinuously rounded, the posterior mar- 

 gin on each side bearing three small, pointed hairtufts. The 

 second and third pairs of legs are normal (the first pair is 

 lacking), the fourth has very large, flat, sharply separated, 

 almost circular segments. Type species: M. winthemi sp. nov. 



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