2 Family Argasidae 



The differences extend to their hahits as well as to their structure. 

 The Argasidae feed moderately, and the change of shape in both sexes 

 is chiefly a dorso-ventral thickening, while the females of the Ixodidae, 

 when gorged, are greatly increased in size, and their coxae widely 

 separated. The Argasidae live for several years, and as a rule lay 

 comparatively few eggs in small batches, have two or more nymphal 

 stages, and may moult after attaining maturity. The Ixodidae probably 

 do not live more than two years, lay a single huge batch of eggs, and 

 moult twice only, on leaving the larval and nymphal stages. 



Family I. ARGASIDAE Canestrini, 1890. 



Family Characters. Non-scutate ticks with leathery integument 

 and slight sexual dimorphism, with capitulum inferior in the nymphs 

 and adults, the palps being free and leg-like, with their articles sub-equal 

 in length. The spiracles are small and usually anterior to coxae iv. 

 Pulvilla absent or rudimentary, porose areas absent on the female 

 capitulum. The capitulum lies partly (larvae) or wholly (adults and 

 nymphs) in a hollow of the overhanging anteriorly protruding body. 

 When gorged the hollow is shallower. 



The Argasidae, even when gorged, never increase much in size, and 

 in their flattened appearance when fasting they bear some general 

 resemblance to bed-bugs. Their principal hosts are man, birds and 

 bats. They are mostly inhabitants of warm climates or choose a 

 habitat in colder climates which assures them protection: thus Argas 

 rejlexus lives in pigeon coops and fowl houses, Argas vespertilionis in 

 the retreats of bats. Ornithodoros moubata and savignyi inhabit native 

 dwellings, retreating into chinks in the walls or dusty floors. The 

 Argasidae appear to be chiefly nocturnal in their habits, like Gimex 

 lectularius, and to prefer dryness. 



The family Argasidae includes two genera, Argas and Ornithodoros. 



N.B. There is some difference of opinion as to the number of 

 genera to be admitted under the family Argasidae. Pocock (1907, 

 p. 189) has advocated the revival of Latreille's genus Caris (or Carios) 

 for the aberrant form vespertilionis, which he considers clearly marked 

 off from other members of the family by the possession of a "conspicuous 

 transverse, slightly curved groove just behind the anus," and he would 

 also remove 0. talaje to another genus, for which he proposes the name 

 Alectorobius, on account of the movable lateral wings of the camero- 

 stome. Now the post-anal structure so conspicuous in vespertilionis, 



