Etving — Significance of Parasitism in Acarina. 25 



I made an attempt to inoculate our common striped 

 ground squirrel, Spermophilus 13 — lineatus with Myohia 

 musculi from a mouse. The parasites took hold at first 

 and caused the ground squirrel much annoyance, but 

 could not establish themselves and soon disappeared. 



A List of Some Trombidium Larvae and Their Hosts. 



In considering the larvae of the Rhyncholophidae, 

 Trombidiidae, Hydrachnidae and Halacaridae, it seemed 

 that the data in regard to all of them and their distribu- 

 tion were so inadequate that it was decided to give lists of 

 species and hosts for only two of the best known genera. 

 These records are taken chiefly from Oudemans. 



ALLOTHROMBIDIUM Bei'leSC. 



A. fuliginosum (Herm.) — Aphis tiliae L., A. sambuci L., A. jaceae L., 



A. evonymi F., A. rosae L., A. fabae, A. ribis. 

 A. poriceps Oudms. — Specimens have been taken upon Homo, but tha 



true host or hosts are unknown. 

 A. inexspectatiim Oudms. — Host unknown. 

 A. italicum Oudms. — Acridium, Mantis, Gryllotalpa. 

 A. tectocervix (Oudms.) — Host unknown. 



A. striaticeps Oudms. — Found on Homo as an accidental host. Its true 



host unknown. 



TROMBIDIUM Fabricius. 



T. grannlatuTTi Oudms. — Host unknown. 



T. muscae Oudms. — Musca domestica, Vesperugo piplstrellus, V. sero- 

 tinus, Plecotus auritus. 

 1'. WicTimanni Oudms. — Found upon Goura sp. 

 T. russicum Oudms. — Upon a bat; host probably accidental. 

 T. inopinatum Oudms. — Crossopus fodiens (Pall.). Talpa europaea L. 

 T. meridionale Oudms. — True host unknown. 

 T. berlesei Oudms. — Hirundo riparia. 

 T. vandersandei Oudms. — Found on the legs of Homo In New Guinea. 



Although the list of species of these Trombidium lar- 

 vae is not large, and doubtless a more careful search 

 would add several more hosts for each species, yet from 

 these data I think we can draw the conclusions ; that they 



