THE LICE 



73 



Fig. 3S. — Haematopinus 

 asini (after Osborn, from 

 Comstoc'k, Bui. No. .5, 

 Bureau of Entomology, U. 

 ,S. Dept. of Agr.). 



1. Haematopinus asini (H. macrocephalus). — Pediculidie fp. 70j. 

 Head long and narrow; antennte attached at lateral protuberances be- 

 hind which are notches lodging the eyes. Anterioi' to this the head is 

 more narrow with borders parallel, terminating 

 in a blunt point. The thorax is much shorter 

 than the head and widens posteriorly. The 

 abdomen is oval, with stigmata placed in the 

 middle of lateral protuberances on the margins 

 of segments. The general color is yellow, the 

 thorax brownish. The female is 3 to 3.5 mm., 

 the male 2.5 mm. in length (Fig. 38). 



2. Trichodectes equi (T. parumpilosus ) . Phil- 

 opteridse (p. 71). — Head slightly longer than 

 broad and semicircular in front of the antennsae 

 which are set well back. The abdomen is oval 



and bears eight trans- 

 verse dark bands, each 

 upon the anterior por- 

 tion of a segment and 

 extending from the 

 middle line about half- 

 way to the margin. 



The general color of the abdomen is yellowish, 

 the head, thorax, and legs chestnut (Fig. 39). 

 3. Trichodectes pilosus. Philopteridse 

 (p. 71). — Somewhat smaller than the preced- 

 ing species. Head broader than long, rounded 

 in front, and slightly widened at the temples. 

 The antennae are inserted well forward, almost 

 on a line with the head's anterior border, in 

 which respect it markedly differs from T. equi. 

 The abdomen tapers posteriorly and has upon 

 the middle ofthe first seven segments darkened 

 spots, less conspicuous than the bands simi- 

 larly located upon T. equi. The head, thorax, 

 legs, and abdomen are hairy on both surfaces. 

 The general color is yellow. 



Pediculosis caused by suctorial lice upon the 

 horse is usually located at the base of the mane 

 and forelock, and at the root of the tail. The hairs about these parts 

 are likely to be scant, broken, or the skin entirely denuded, due to 

 the rubbing against anything within reach. During the act of rubbing 

 the animal has a peculiar habit of protruding the upper lip, or, if in 

 reach of another animal, will gently bite it. 



Fig. .39. — Trichodectes 

 parumpilosus (after Osborn, 

 Bui. No. .5, Bureau of Ento- 

 mology, U. S. Dept. of Agr.). 



