HOG-LOUSE 649 



by means of which the louse is able to pierce the skin of the hog and 

 suck blood. On each side of this piercing stylet will be noted 

 five small hairs. 



A little further back along the head of the louse will be seen two 

 small arm-Hke feelers — the antennse. These feelers will be found 

 to be composed of small segments, each antenna having five seg- 

 ments. Just behind the antennse there are two deep notches, one 

 on either side of the head. Deep in the bottom of these notches are 

 located the eyes of the parasite. 



When we examine the chest or thorax of the Haematopinus suis 

 it is found to have attached on either side three legs, giving the 

 parasite six legs in all. These legs are jointed and divided into 

 segments, and at the end of the last segment the louse is provided 

 with a pair of claws, one large and one small. Between these claws 

 there is a thin disk-like membrane, and on this membrane a number 

 of small booklets, which give the parasite exceedingly strong power 

 of attaching itself to the skin of the hog. 



The posterior portion of the body or abdomen of the louse is 

 wider than the chest and carries no legs. The male parasite can be 

 distinguished from the female by the appearance of the abdomen. 

 In the male parasite there is a dark streak to be seen on the middle 

 and under surface of the last three segments of the abdomen. The 

 male parasite is also considerably smaller than the female. 



In general appearance the Haematopinus suis is a grayish- 

 colored parasite. The edges of the head, thorax, and abdomen are 

 dark in color. On the animal body these lice are very easy to 

 find, as the thin hair of the hog gives them but little protection, 

 and they are readily seen. 



These parasites multiply by means of eggs. The female louse 

 lays a large number of eggs which are known as "nits." In a herd 

 infested with lice these nits are easily found. The egg, which is 

 quite small, yet large enough to be readily seen with the unaided 

 eye, is cemented on the hair by means of a gelatinous substance 

 poured out of the mouth of the mother parasite. The egg is of a 

 yellowish or yellowish-white color, oval in shape, and tapers some- 

 what to a point at the end, which is attached to the hair. The 

 free end is somewhat larger, and is covered by a lid-like cap, which 

 is lifted off by the young louse when hatched. Through the 



