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 
arecalled ‘‘blue-lice.’’? They occur in great- 
est numbers during the spring of the year, 
when they may be found in ail stages of 
growth, from the freshly laid egg 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. 
Pee iio cecne The sides of head bear bristles. The eyes 
ly enlarged. Original gre very 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 
ofeach segment. At thesides of the last dorsaljoint of 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 pilosus Giebel). 
This parasite is also a very familiar insect, being found 
upon the horse and ass, where crowds of them are usually 
found upon the throat, mane, and neck. The species hasnot 
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 
