Mites and Lice on Poultry. 



15 



than on the feathers. It does not always confine itself to the body, 

 sometimes being taken on the head, neck, and legs. It favors those 

 portions of the skm which are not densely feathered. On chickens 

 it is partial to the region just below the vent, but m heavy infestations 

 it is abundant on the breast, under the wmgs, on the back, and also 

 on the head, neck, and thighs. When the feathers are parted it is 

 seen running rapidly upon the skin to seek protection. With young 

 chickens it is more abundant on the back than around the vent. 



This louse is rather large and robust, straw yellow in color, with 

 some dark spots due to food within 

 the digestive tract. The two sexes 

 are shown in figures 9 and 10. 



The body louse is probably the 

 most injurious species on grown 

 chickens, but it also infests young 

 fowls, sometimes seriously. As it re- 

 mains on the skin of the host, irri- 

 tation is kept up constantly. Often 

 a marked reddening of the skin of 

 the fowl in the regions most heavily 

 infested results, and in some cases 

 scabs and blood clots are formed. 



The eggs are deposited in clusters on 

 the base of the feathers, usually being 

 attached to the lowest barbs along 

 the shaft. They are most abundant 

 on the small feathers below the vent, 

 where the masses of eggs sometimes 

 become very large — fully half an inch 

 in length. As the lice continually 

 add eggs, the masses are extremely 

 large when seen several months after 

 molting. In the case of young fowls 

 the eggs are often deposited in num- 

 bers on down or small feathers and on hairs about the head and 

 throat. A mass of eggs of this species is showTi in figure 11. 



The eggs hatch in about a week, and the adult stage is reached 

 from 17 to 20 days after the eggs are deposited. This louse has 

 a short period of growth both in summer and in winter; hence fowls 

 which are not actively fighting the louse become swarming with 

 them in a very short time. Fortunately the heat of the body is 

 necessary for the hatching of the eggs, and the lice themselves die 

 in a very short time when off the fowl. For this reason little attention 

 need be given to lice and eggs which are shed by the host during 



Fig. 9.— Body louse { Menopon Useriatum): 

 Male, top view. Greatly enlarged. 

 (Original.) 



