Feb. '08] 



JOURNAL OF ECONOMIC ENTOMOLOGY 



41 



ADAPTATIONS AS FACTORS IN HOST RELATIONSHIP. 



represented by the adaptation 

 ' for attachment ■{ of the front pair of legs of the 

 Ixodidae, to attachment. 



f Adaptation o f 

 function and 

 structure. 



Adaptation 

 in the ticks. " 



for protection 



represented by shape of en- 

 gorged larval nymphs and 

 adults of Argas miniatus and by 

 the increased length of mouth 

 parts of the Ixodinae. 



1-molting ( Margaropus&^^s., 

 on host. <Dermacentor 



nitens, etc. 



for attachment <; g-attaclnnent 



-attaclunent \ t.^ 

 toanyhost. i^^^5^«P^«^^«- 



3-adaptation f^'^'^^ miniatm, 



of habit toJ,-^^'^'"«^^f«;*? 

 ^< leporis j)alu»tns, 



Oi'mthodoros 



l^megnini. 



habit 

 host 



Adaptation of < 

 habits. 



4-acq uired f 

 greater vi- <( Many species, 

 tality. t 



ri-acceleratedf^^T'"**^'"^''' 

 " ^ 1 Margaropus, 



[ anmdatus, etc. 



l^ for protection 



ment. 



{Ornithodoros 

 megnini, Derma- 

 centor nitens, 

 Haemaphysalis 

 sp. on birds. 



3-nocturnal 

 habits. 



Argas sps. 



