ENTOMOLOGY

ss~SANITARY ENTOMOLOGYfemale about one-eighth to one-fifth of an inch, while the males are alittle smaller and a little narrower.The eggs or nits are white and can be distinctly Seen glued tightly tothe hairs along the shoulders. From thirty-five to fifty eggs are laid bythe mature females and these are laid a few each day. The egg-layingperiod may extend over a period of ten to fifteen. days. These eggshatch in from seven to .eight days and the young hee commence drawingthe cow's blood near the point where they were hatched. The rateof growth depends somewhat upon the blood supply in the portion ofskin where they work. They mature in from fifteen to eighteen days,when the females in turn lay eggs.The long-nosed cattle louse, Haematopinus 'lJituli Linnaeus. is oftenspoken of as the "blue louse," or the louse attacking calves, though itOccurs frequently on older stock. It is distinguished by being darker incolor and slender in shape with a long pointed head. When seen on thecattle it seems to be literally standing on its head with mouth-parts buriedin the skin, feeding on tIle blood of the animal that it infests. It isfound more commonly on the neck and shoulders of the animal.The mature insects are a dark bluish gray in color, giving them anappearance of being either blue or black, and they are about one-eighthof an inch long. Their color and their small size allow them to passunnoticed especially on stock of a darker c~lor. If one will turn backthe hair until the skin of the animal can be seen, their pJ.'esence may bemade out by the shining surfaces of the abdomen. If they can be madeout on the calves having white markings, they can usually be assumed tobe present on the others, and there should at least be a close observationof all the calves.The eggs of this louse are dark, nearly black, and hatch in fromeight to nine days. Like the previously mentioned species, these licemove about but little before maturity, but continue feeding near thepoint where they were ha.tched. They in turn lay eggs in fifteen toeighteen days.BITING LICEThe little red cattle louse, Trichodectes 8calaria Nitzsch, is perhapsthe most generally found on cattle. It seems to be out of place as it isof the biting group, and this group is most commonly found on birds. Itfeeds on the hair and loose scales of the skin, and the drier the skin of thecow, the more,numerous these lice become, until they can be made out bythe thousand, closely matted in the hair. They are most commonlyfound on the neck and shoulders, though in bad cases they are foundpretty generally over most parts- of -the animal. Unlike the two previ-