To RID HORSES of lice, DDT has given good results. It should be used in the same way as for lice on cattle.

THE SHEEP-TICK, also called sheep ked, is not a true tick; it is a wingless fly. It is a common pest of sheep and will also attack Angora goats. It spends its whole life on the animal. The adult female deposits a round, whitish "egg," which is really the resting stage or pupa. It is glued lightly to the wool and turns to a dark brown in a day or so. The adult sheep-tick emerges in 2 or 3 weeks and begins to suck blood at regular intervals. It is controlled by insecticides. I think sheep-ticks could be completely eliminated by coordinated treatments of all sheep and Angora goats. Derris or cube dips are highly effective. As little as 8 ounces of a material containing 5 percent of rotenone used in 100 gallons of water makes a good dip. DDT, toxaphene, chlordane, TDE, methoxychlor, and lindane, used as described for controlling lice on sheep and goats, are equally as good. Sprays, if used, should be applied thoroughly at double the dip strength, preferably immediately or within a few weeks after shearing, when the wool is short.

POULTRY are often seriously affected by lice, mites, and fleas, as well as by the fowl tick, which has already been discussed. Heavy infestations of lice alone may reduce egg production of chickens by as much as 10 percent. A close examination of cracks, crevices, and other hiding places in poultry houses may reveal thousands of small red objects less than one-twenty-fifth inch in diameter the red color is evidence that mites can sap a great deal of blood from the flocks. It is not unusual among neglected poultry flocks to see black rings around the eyes of young chicks or black spots on wattles and combs of chicks and older poultry. Close examination reveals that the rings and spots actually are hundreds of shining black fleas, engorged with blood. The chickens may be found to harbor hundreds of lice around the head, wing feathers, or vent. One may even note feathers on the vent glued together by literally thousands of small nits or eggs laid by one of the most common species, the body louse.

No longer need poultrymen tolerate infestations of these parasites on their poultry.

Thorough treatments of poultry houses with sprays containing 0.5 percent of lindane will usually control the mites. Sometimes DDT has given good results when used as a 5-percent emulsion or as a 5-percent oil solution. Creosote and carbolineum sprays, although somewhat objectionable to use because of the odor, have been used successfully. Whatever the material, however, it must be applied thoroughly. Proper clean-up to prevent accumulations of droppings, feathers, straw, and other refuse will eliminate some hiding places for the insects and mites and will make possible more thorough and effective treatments with insecticides.

Ordinary lard put on the heads of the fowls will destroy the fleas, but the aim should be to clean up and treat the infested places with a DDT dust or spray. Good results will be obtained if an emulsion, wettable powder, or oil spray containing from 2.5 to 5 percent of DDT is applied to the infested areas at the rate of about 2 gallons for each 1,000 square feet. Lindane sprays containing 0.5 percent of the insecticide can also be used with good success.

Lice on poultry can be destroyed by applying a pinch of sodium fluoride as a dust to various parts of the chicken, especially the head, back, under sides of wings, and the vent region. A 5 percent DDT dust can also be used with good results. Good control can be obtained without disturbing the chickens by applying a 1 percent lindane spray to the roosts or by painting it on with a brush. The lindane gives off sufficient vapor to kill the lice when the chickens perch on the roosts. Nicotine sulfate roost paint has also been used in that way.

E. F. KNIPLING is in charge of the division of insects affecting man and animals, Bureau of Entomology and Plant Quarantine. Since 1931 he has conducted research on insects that attack livestock and man.

Information on the role of insects in transmitting diseases and worm parasites to livestock will be found in the chapters "Carriers of Animal Diseases," page 161, and "Insects and Helminths," page 169. Some statistics on the losses caused by livestock pests will be found on page 144.

Blow fly.