Injurious to Man. 23 



also annoyed by the Pcdiculoides. Willcocks records this mite as 

 occurring at several localities in Egypt. It has also been found 

 attacking soldiers handling stored barley in Algeria. There are 

 specimens in the British Museum from Nyasaland. 



In Philadelphia many cases of dermatitis due to this mite 

 have occurred over a period of several years, usually during the 

 months of May and October. The disease in this locality was 

 carefully studied by Schamberg and Golberger, who detected the 

 presence of the mite in straw mattresses slept upon by the 

 patients. 



Webster states that there was an epidemic of dermatitis due 



Fig. 10. 



Pediculoides ventricosus (Newport), gravid female; the mite 

 causing Grain-Itch, much enlarged. (After Banks.) 



to Pediculoides in Ohio and other Western States of America in 

 the year 1908, persons engaged in threshing grain or using the 

 straw for mattresses or packing having been badly affected. 



Genus — Tarsonemus, Canestrini and Fanzago. 



Specimens of Tarsonemus have been found in cancerous tissues 

 taken from man and several domestic animals and preserved in 

 alcohol. Dahl and Saul, believing them to be the cause of cancer, 

 described these specimens of Tarsonemus under several specific 



