BITING-LOUSE OF CATTLE. 113 



BITING-LOUSE OF CATTLE. 



{Trichodectes scalaris Nitzsch). 



This louse (fig. 85) is well-known the world over, and is 

 sometimes so abundant upon cattle as to become really in- 

 jurious, though not as much so as suck- 

 ing-lice. They are distinguished by the 

 herdsmen as "red-lice," while sucking-lice 

 are called "blue-lice." They occur in great- 

 est numbers during the spring of the year, 

 when they maj^ be found in all stages of 

 growth, from the freshly laid &gg, to the 

 adult insect. They have a heart-shaped 

 head, as broad as long, with triangular 

 dark spots in front of the head and feelers, 

 ''^**^ which latter are located in depressions. 



Fig. 85 — Biting- The sides of head bear bristles. The eves 



louse of cattle. ..Great 



ly enlarged, originaf arc vcry Small. The first segment of 

 the thorax is narrower than the second; between both, on 

 either side, is a triangular piece, so that the segments show 

 lateral corners. The thorax is covered with bristles; the 

 claws are slender and but little bent, the abdomen elongated- 

 oval; the edges of segments show^ corners; the dorsal surface 

 bears bristles, and brown transverse bands mark the middle 

 of each segment. At the sides of the lastdorsaljointof abdo- 

 men is a peculiar chitinous appendage. The general color 

 is reddish-yellow, the abdomen paler than head and thorax. 

 Length 1.5 to 2mm. 



BITING-LOUSE OF THE HORSE AND ASS. 



( Trichodectes j)ilosns Giebel) . 



This parasite is also a very familiar insect, being found 

 upon the horse and ass, where crow^ds of them are usually 

 found upon the throat, mane, and neck. The species has not 

 as yet been found in our state. The head of this parasite is 

 rounded in front, and as long as broad. Marginal spots 

 occur in front and behind the feelers; upon the middle of the 

 head is also found a dark spot, while its posterior margin is 

 dark brown. The thick feelers start well forward on the 



