54 



THE ITCH-MITE OF MAN. 



THE ITCH-MITE OF MAN. 



{Sarcojjtes scabiel De G. var. ]i(>)ihii!x). 



This mite (fig. 27 and 28) is very minute, whitish, 

 and barely visible to the naked eye unless moving over a 

 dark surface. Its body is rounded and soft, in the female 

 with small roundish scales upon the middle of the back ; in 

 the male with but fewisolated scales; the surface of the body 

 has radiating lines or ridges. The mites resemble in a 

 general way a minute tortoise, are very sluggish during the 

 day, but become quite active during the night in a warm bed, 

 and can even leap to some distance. The head is distinctly 

 separated from the rest of the body, and possesses four pairs 



Fig. 27.— Itch-mite of 

 man, male. Greatly en- 

 larged. Original 



Fig. 28. — Itch-mite of man, 

 female. Greatly enlarged. Orig- 

 inal. 



of jaws which are needle-like. The mitehaseight legs, four in 

 front and four behind ; when young, or as a larva, it has 

 but six legs. The sides of the body and legs bear long bristle- 

 like hairs ; there are six upon the thorax and fourteen upon 

 the abdomen. The males (fig. 27) are quite different from 

 the females (fig. 28), are much smaller, and have bell-shaped 

 suckers upon the ends of their legs. The female is about one- 

 sixtieth to one-seventieth of an inch in length (0.45mra. long 

 and 0.35mm. wide), the male (0.23mm. bv 0.19mm., and the 



