TarsonemidcB 



69 



Pediculoides ventricosus, 

 male. After Webster. 



They often attack people working in poultry houses or handling and 

 plucking infested fowls. They may cause an intense pruritis, but they 



do not produce a true dermatosis, for 

 they do not find conditions favorable for 

 multiplication on the skin of man. 



Tarsonemidae 



The representatives of the family Tar- 

 sonemidae are minute mites, with the body 

 divided into cephalothorax and abdomen. 

 There is marked sexual dimorphism. 

 The females possess stigmata at the 

 anterior part of the body, at the base of 

 the rostrum, and differ from all other mites 

 in having on each side, a prominent clavate 

 organ between the first and second legs. 

 The larva, when it exists, is hexapodous 

 and resembles the adult. A niunber of the 



species are true parasites on insects, while others attack plants. 



Several of them may be accidental parasites of man. 

 Pediculoides ventricosus 



(fig. 52 and 53) is, of all the 



Tarsonemidae reported, the 



one which has proved most 



troublesome to man. It is a 



predaceous species which 



attacks a large number of 



insects but which has most 



commonly been met with by 



man through its fondness for 



certain grain-infesting insects, 



notably the Angoumois grain 



moth, Sitotroga cerealella, and 



the wheat straw-worm, Iso- 



soma grande. In recent years 



it has attracted much atten- 

 tion in the United States and 



its distribution and habits 



have been the object of detail- 



d»4-..J.. t,,, TXr^U^+n- f-r ^■,^ 53. Pediculoides ventricosus, 

 ^ study by Webster (19OIJ. After Webster. 



gravid female. (X 80). 



