INSECTS AFFECTING MAN AND ANIMALS 199 



They are more common 



one-fourth of an inch long, or a gray color, the body broadly 

 oval and the head narrow. 



The Biting Cattle Louse * is so called because its 

 mouth-parts are fitted for biting instead of sucking, it be- 

 longing to the same order as the common hen louse. They 

 are recognized as " little red lice " by cattle men, in con- 

 trast to the bluish sucking species, 

 in spring, but are not injurious 

 unless occurring in very large 

 numbers. 



Spraying the affected animal 

 with kerosene emulsion diluted 

 ten times, or with tobacco ex- 

 tract (Black-leaf 40, 1 part to 

 800), or rubbing the affected 

 parts with sulphur, lard and 

 sulphur, or lard and kerosene, 

 will destroy these lice. Usually 

 these parasites are introduced 

 into a herd on animals which 

 have been neglected, which should 

 be treated at once so as to pre- 

 vent further spread. Recent ex- 

 periments at the West Virginia Agricultural Experiment Sta- 

 tion indicate that one of the best means of eradicating these 

 lice is by the use of blue ointment. On cattle the hair should 

 be clipped close to the skin on a space half the size of one's 

 hand. On hogs apply about two square inches, using only 

 enough to smear over the skin and rub on with the finger. 

 Apply the ointment in the crotches, back of the ears, be- 

 hind the shoulders or any place where the animal cannot lick 

 it. The ointment is a mercury preparation which can be 

 * Trichodectes scalaris Nitzsch. Order Mdlophaga. See page 37. 



FIG. 141. Long-nosed ox- 

 louse (Hcematopinus vituli.) 

 (U. S. Dept. Agr.) 



Female, under surface of last 

 segments of abdomen of same, 

 showing brushlike organs, 

 larged. 



En- 



