Ew'ing — Significance of Parasitism in Acarina. 61 



Zoophaga. 



Tarsonemidae (in part). 

 Listrophoridae. 



Analgesidae, Canestrinidae, Sarcoptidae, Cytoleichidae. 

 Demodecidae. 

 Depending upon the conditions imposed by the life of tlie host. 

 Hydroxenous. 



Larvae of Hydrachnidae and Halacaridae. 

 Gen. Atax. 

 Geoxenous. 



Myobia and Psorergates. 

 Gekobia. 



Ixodidae, Dermanyssldae (in part), parasitic Gamasidae. 

 Cilliba. 



Parasitic Tarsonemidae. 

 Listrophoridae (In part). 

 Canestrinidae. 

 Sarcoptidae (mostly). 

 Cytoleichidae. 

 Demodecidae. 

 Aeroxenous. 



Harpyrhynchus, Ptcobia and Syringophilus. 

 Larvae of Rhyncholophidae and Trombidildae. 

 Argasidae, Dermanyssldae (in part). 

 Listrophoridae (in part). 

 Analgesidae, some of the Sarcoptidae. 

 Depending upon the number of host species. 

 "With a single host species. 



Parasitic Cheyletldae (in part). 

 Gekobia (?), 

 Cilliba (?). 



Listrophoridae (In general). 

 Analgesidae (in part). 

 Canestrinidae. 

 Sarcoptidae (in general). 

 Cytoleichidae (?). 

 Eriophyidae (in part). 

 With more than one host species. 

 Parasitic Tetranychldae. 



Larvae of Rhyncholophidae, Trombidildae, Hydrachni- 

 dae and Halacaridae (in general). 

 Ixodidae, Argasidae, Dermanyssldae and parasitic 



Gamasidae. 

 Parasitic Tarsonemidae. 

 Analgesidae (in general). 

 Sarcoptidae (a few species). 

 Demodecidae (?). 

 Eriophyidae (in part). 



