THE LICE 



75 



This species is found upon calves, though it will also, — probably as 

 frequently, — infest adults. 



3. Trichodectes scalaris. Philopterida^ (p. 71). — Head cone-shaped, 

 rounded at the temples and in front, about as broad at the temples as 

 long. The antennoe are inserted well back 

 and are usually directed backward. The al)- 

 domen is not so tapering as in the ])iting louse 

 of the horse, and the median spots are larger, 

 forming bands which are quite distinct. The 

 general color is white. It is somewhat smaller 

 than the species uifesting the horse (Fig. 42). 

 This is a very common and widely dis- 

 tributed species, frequently found upon cattle 

 in cohabitation with the sucking lice. 



Pediculosis of 

 the ox, caused 

 by either the 

 short or long- 

 nosed species, 

 is most likely 

 to be found 

 about the ears, 



base of the head, and along the dorsal 

 line of the neck, back, and loins. The 

 intense itching causes the animal to rub 

 against any convenient object, and there 

 is frequent licking of the parts which can 

 be reached with the lough tongue. As a 

 result of this rubbing large patches of 

 skin may be entirely denuded of hair, 

 and the skin itself in severe cases may 

 become pustular and scabby. 



Contrary to what has been observed 

 in the horse, biting lice probably occur 

 more frequently upon the ox than the 

 sucking species, therefore lousiness of 

 cattle is usually accompanied by less 

 itching. As to their location the l)iting lice of cattle do not limit them- 

 selves, usually spreading to all parts of the body. They may frequently 

 be observed crawling out upon the hairs and, when one is removed and 

 examined with a hand glass, one or more hairs will often be found in the 

 clutch of its claws. 



Fig. 41. — Hsematopinus 

 vituli: female, under surface 

 of last segments of abdomen 

 of same (after Osborn, Bui. 

 No. 5, Bureau of Entomol- 

 ogy, U. S. Dopt. of Agr.). 



Fig. 42. — Trichodectes scalaris 

 (after Osborn, Bui. No. 5, Bureau 

 of Entomology, U. S. Dept. of 

 Agr.). 



