Acarina 



267 



e. Palpi small, three segmented, adhering for some distance to the lip; 

 ventral suckers at genital opening or near anal opening usually 

 present; no eyes; tarsi often end in suckers; beneath the skin on 

 the venter are seen rod-like epimera that support the legs; body 



often entire. Adults frequently parasitic SARCOPTOIDEA. 



f. With tracheae; no ventral suckers; legs ending in claws; body 

 divided into cephalo thorax and abdomen; the female with a 

 clavate hair between legs I and II. Usually not parasitic 



on birds and mammals TARSONEMID^E 



g. Hind legs of female ending in claw r and sucker as in the other 



pairs PEDICULOIDIN^E 



To this sub-family belongs the genus PEDICULOIDES 

 P. ventricosus is described on page 69. 



155. Margaropus winthemi, male. After 

 Nuttall and Warburton. 



156. Margaropus winthemi, 

 capitulum and scutum, 

 After Nuttall and War- 

 burton. 



gg. Hind legs of the female end in long hairs TARSONEMIN^I 



Tarsonemus intectus Karpelles, normally found upon grain, 

 is said to attack man in Hungary and Russia. Other 

 species of the genus affect various plants (c.f. fig. 150, g). 

 ff. Without tracheae; no such clavate hair. 



g. Genital suckers usually present; integument usually without 



fine parallel lines, 

 h. Legs short, without clavate hair on tarsi I and II. On 



insects CANESTRINID^E. 



hh. Legs longer, with a clavate hair on tarsi I and II, Not 



normally parasitic except on bees TYROGLYPHID^B 



i. Dorsal integument more or less granulate; claws very weak, 

 almost invisible; some hairs of the body plainly feathered; 



ventral apertures large Glyeiphagus Her. 



This genus occurs in the United States. In Europe the 

 mites have been found feeding on all sorts of substances. 

 They are known as sugar mites and cause the disease 



