58 



SCAB OF HOG. 



NORWEGIAN ITCH-MITE OF MAN. 



{Sarcopfes crustosw Fuerst.). 



This itch-mite is very similar to the common one infest- 

 ing man, but is smaller and darker. It was first described in 

 Christiana, Norway, and seems to be confined to that country, 

 though it has several times been found elsewhere. It has so 

 far as known not been found in Minnesota, and it is to be 

 hoped never will find its way into our state, as it is a very 

 much worse parasite than the common itch-mite. 



SCAB OF HOG OR THE SCALE-BEARING 

 ITCH-MITE. 



(Sarcoj)tes scriblel var. .y;//.v) or {Sdrccqjtes squamiferus Fuerst.). 



This mite is found upon the skin of dogs, hogs, goats, sheep, 

 and probably of man, whereit produces scab. Theuppersur- 



Fig. 30.— Scab-mite of 

 the hog, male. Greatly en- 

 larged. Original. 



Fig. 31.— Scab-mite of the hog .fe- 

 male and egg. Greatly enlarged. 

 Original. 



face of the female bears a number of triangular scales, which 

 are not arranged in regular rows. The first row of scales 

 commences behind the first spines upon the thorax. Head 

 and legs are more hairy than in the common itch-mite. There 

 are 6 sickle-shaped thorns upon the thorax, and 13 or 14 

 pointed ones upon the back. 



The length of the male varies from 0.25 to 0.32 mm., 



