6 Farmers’ Bulletin 1150. 
_ Appearance.—The sucking body louse has a head somewhat longer 
than the thorax (fig. 1). The abdominal segments bear two rows of 
long hairs. The male is 2.1 millimeters 
(about one-twelfth of an inch) long and the 
female is 2.8 mm. (about one-tenth of an 
inch) long. There is an inconspicuous eye 
on each side of the head. The wool in the 
region attacked by this louse is usually dis- 
colored and contains numerous brown par- 
ticles, the fecal deposits of the lice. 
The foot louse has a short head, as wide 
as it is long, which merges into the thorax, 
with reddish oblique bands on each side (fig. 
2). No eyes are present. The abdominal 
segments bear two rows of hairs, of which 
: Bes: sh a those at the lateral margin are longer than 
U | - the others. The female is 2.2 mm. (about 
eore nT one-twelfth of an inch) long and 1 mm. (one- 
il, twenty-fifth of an inch) wide; the male is 
broader and flatter. This is a sucking louse 
like the preceding species. 
FIG. 1—Sucking body louse The biting louse has a head that is wider 
(Hematopinus ovillus) . . . 
Female, back view. Highly than long, with a broad, round anterior 
magnified. (From Neu. end (fig. 3). The abdominal segments 
mann, 1907.) a a 
show a median dark line and have only a 
single row of hairs. The male is 1.4 mm. (about one-twentieth of 
an inch) long and the female is 1.6 mm. long. 
Life history—The eggs of the va- 
rious species of sheep lice are attached 
to the hair or wool in the sites cus~ 
tomarily infested by the adult lice. 
The eggs of the sucking lice are said 
to hatch in 10 to 18 days; those of 
the biting lice in 5 to 8 days ordina- 
rily, or 10 days in cold weather. 
Available evidence indicates that the 
young lice become mature and begin 
laying eggs in the course of about 
two weeks after hatching. The suck 
scong)\ \ y) (Geaes 
—=>=- 
— 
I 
eo T ery 
{\) 
; i ‘ ; Fie. 2.—Sheep foot louse (Linog- 
ng lice, as the name implies, are nathus pedalis). Adult female 
bloodsuckers. The biting lice feed 20. che, iret a 
. : born, 1896.) 
on the epithelial scales and other 
material on the surface of the skin. Lice usually cause little 
trouble in summer, but become more numerous and annoying in 
winter, 
ws) iets ality igh were 
