346 SANITARY ENTOMOLOGY 



The biting louse, Trichodectes sphaerocephalus Nitzsch, of sheep is 

 much more frequently met with than the sucking species and has been 

 taken in various parts of the United States. It never seems to become 

 abundant on the heavily wooled breeds. 



It has been reported that the thin wooled sheep raised by the Indian 

 tribes in northern New Mexico and Arizona are often heavily infested with 

 lice. Undoubtedly there is a close correlation between the character and 

 amount of wool and the reproduction of lice on the host. 



Sodium fluoride may be successfully employed against the biting louse 

 but on account of the close covering of wool the application must be 

 thorough. The same method of application as suggested for the biting 

 lice of goats should be used. Of course where sheep are dipped for the 

 sheep tick (Melophagus ovinus), or scabies, the lice will be kept under 

 control. Nicotine sulphate or lime-sulphur arsenic dip seem very effective 

 against both the lice and the sheep tick. The former should contain about 

 0.07 per cent of nicotine sulphate. The latter consists of a lime-sulphur 

 dip of the formula : 8 pounds unslacked lime, 2-i pounds flowers of sulphur, 

 and water to make 100 gallons. Take 150 gallons of this concentrate 

 and 350 gallons of warm water and add a concentrated arsenical solution 

 containing 12 gallons water, 12 pounds sal soda and 4 pounds white 

 arsenic. 



BITING AND SUCKING LICE OF GOATS 



Goats of all breeds are subject to the attack of lice but this tendency 

 seems especially marked among the angoras. The biting lice consisting 

 of two species, Trichodectes cUm'ax Nitzsch and T. hermsi Kellogg and 

 Nakayama, are the principal species. The former of these is the pre- 

 dominant form. 



Practically every flock of goats in the Southwest is infested and 

 some years the injury is very marked. The annoyance retards the growtli 

 of the kids and injures the condition of flesh of the goats, but the most 

 obvious loss is brought about in the reduction of the mohair clip. The 

 irritation produced by the lice induces much rubbing, which of course 

 pulls out and mats the mohair and there also appears to be considerable 

 loss through the actual cutting of the hair by the lice themselves. Cer- 

 tain large goat raisers in Texas estimate a loss of twenty per cent in the 

 clip some years and often individual goats are so denuded that shearing 

 is not profitable. The quality of the mohair is also said to be materially 

 affected when the lice are abundant. 



The lice are present on all parts of the host, especially on the 

 heavily haired portions and the whitish eggs are attached to the hairs 

 next to the skin. 



The sucking louse, Linognathus stenopsis Burmeister, frequentl}' be- 



