374 



PESTS OF DOMESTIC ANIMALS 



The Screw-worm '{Ckrysomyia macellaria Fab.) 

 Exposed wounds or even the bites of ticks form the breeding ground 

 of the whitish maggots of this species. Eggs are laid in large numbers 



in such places by the adult fly, 

 and the young burrow in the 

 surrounding tissues, later enter- 

 ing the ground to transform. 

 There may be several genera- 

 tions annually. 



Prompt treatment of chance 



wounds, and dipping to kill or 



prevent ticks, are the best 



Fig. 599. — The Screw- worm Fly. En- measures to adopt. In the 



larged and natural size. Original. treatment of WOUnds a solution 



of carbolic acid, 1 part, water, 30 parts, is excellent, followed by a 



dressing of pine tar. 



Sucking Lice on Domestic Animals 



The larger animals, including cattle, horses, swine, and others, 

 are often infested with sucking lice, which frequently cause great 

 irritation. Several species are conmion. 



The Short-nosed Ox Louse {Hmmato- 

 pinus eurysternns Nitzsch) is slaty in 

 color, one eighth to one fifth of an inch 

 long and about half as broad. Usually it 

 is most troublesome on the neck and 

 shoulders. 



The Long-nosed Ox Louse {Hoematopinus 

 vituli Linn.) is slender, one eighth of an 

 inch long. Its head is distinctly elongated. 



The Hog Louse ( Hcematopinus urius 



Nitzsch) is gray, one fourth of an inch 



long, the body broadly elliptical, the 



u A T5 ji • / . ^ • f ^^ , Fig. 600. — The Short-nosed 



head narrow. Badly mfested pigs fail to q^ Louse. Enlarged and 



make proper gains in weight. natural size. Original. 



