100 PARASITES OF THE DOMESTIC ANIMALS 



vided with bristles or fine hairs, the tarsi terminating in two hooklets. 

 Respiration is by tracheae. There are two eyes, one located upon each 

 side of the cephalothorax. 



Trombidium Holosericeum 



Trombidiidse (p. 99). — Body red and nearly square; slightly narrower 

 posteriorly where the terminal border is slightly concaved; body and 

 legs covered with bristly hairs. Eyes pedunculated. About 1 mm. in 

 length. 



Habits and Effect. — In the adult stage the Trombidium is free- 

 living, feeding upon the juices of plants and small insects. It is only 

 parasitic in its larval condition, in which stage it will inhabit insects 

 and attack warm-blooded animals as well. Living in the tall grass and 

 upon the under side of the leaves of weeds, they are brushed off upon 

 the hands or clothing of people and upon the bodies of animals as they 

 pass through the vegetation. They then proceed to burrow into the 

 skin, setting up a most exasperating itching with the formation of 

 reddened patches often covering considerable areas. This phase of 

 the mite's parasitism is pecuhar in that it invariably perishes in the act 

 of entering the skin. It is likely to be most troublesome during the late 

 summer and autumn, the name Leptus autumnalis, under which the 

 larval stage of the mite has been described, being derived from this fact. 



Man is most often attacked about the lower parts of the legs and upon 

 the hands. Among domestic animals, those which frequent locations 

 densely covered with vegetation are the most likely to suffer. Hunting 

 dogs especially are exposed, and on returning from the field will often 

 exhibit symptoms of great itching about the face, paws, inner thighs, 

 and belly, the parts most often attacked. Horses will be affected prin- 

 cipally below the knees and hocks. 



Treatment. — As the larval mites die upon entering the skin, the 

 source of the irritation is soon eliminated and the intense itching will 

 usually rapidly subside, leaving areas of epithelial exfoliation over the 

 parts affected. Recently exposed animals will be relieved somewhat by 

 frictions with a cloth sprinkled with benzene, or by the application of a 

 mixture of equal parts of hme-water and hnseed oil, or sulphur ointment 

 may be used. Sponging with a solution of carbolic acid at about three 

 per cent, strength in water to which a little glycerin has been added, 

 will do much toward reheving the itching. Ammonia-water, or a solu- 

 tion of bicarbonate of soda are both of value for this purpose. 



Persons working or passing through infested districts will, in con- 

 siderable degree at least, be protected from attack by applying a mix- 

 ture of kerosene and glycerin to the hands and ankles. 



