8 
THE COLORADO EXPERIMENT STATION 
Figure 6.— Goniocotes liuiogaster, a louse (from a hen), ventral view; a, mout 
parts; b, antennae; c, hooklets on free extremity of leg. The small mark to tl 
right indicates the natural size. 
Figure 7.— Lipeurus bacillus, from the pigeon. Letters indicate same parts i 
in Fig. 6. 
Figure 8.— Sarcoptes mutans, variety gallinae, the scab parasite producin 
scaly legs in the hen. a, the mouth parts with which it wounds the skin an 
causes serum to exude; b, the short legs; c, the small dot indicates its natural siz 
MITES 
Scaly Legs (Scabies) 
This disease is caused by a parasite (Sarcoptes mutans variety gallinae; 
which belongs to the same family as the scab parasite of cattle, horses, sheej 
hogs, cats and dogs. The parasite is often called a mite, owing to its sma 
size. In Fig. 8 its size is indicated by a small mark, to the right of the drav 
ing of the parasite, which is magnified 100 times. In the drawing, note th 
short, strong, stubby legs, and the mouth parts arranged for biting. 
CONDITION PRODUCED.—This parasite attacks chickens, turkeys, an 
cage birds, but the writer has not observed it on geese and ducks. It attack 
the unfeathered portion of the leg above the foot and often the top portion c 
the toes. The minute parasite crawls under the scale of the legs and ther 
irritates the tissue, for the purpose of obtaining food with the mouth part 
as pictured in the drawing referred to above. As a result of this irritatioi 
a vesicle or small blister appears. The blister, practically microscopic in size 
after a time ruptures, the serum dries, and makes a minute scale. As th 
parasites become more numerous, by continually irritating the parts, the 
cause a piling up of scab and the leg presents an appearance like Fig. 9. Th 
parasites can be found as minute white specks in the serum between the sea 
and leg. Both legs are usually affected at the same time. Itching is presen 
and the birds may be noted to pick at the parts. Itching is more intense a 
night. The bird may become weak, stop laying and even may die. 
LIFE HISTORY.—The female mite lays her eggs under the scabs where 
in about ten days, if conditions are favorable, they hatch. The larvae (younj 
mites) now moult several times and finally arrive at the mature stage. 
The tearing off of scabby patches favors the escape of the parasite, an( 
other birds become infested by being placed in quarters occupied by infestee 
birds, or by introducing an infested one into the flock. 
TREATMENT.—Soak the scabby patches with soapy water and the 
