EXTERNAL PARASITES 217 
with a mixture consisting of three parts of kerosene to one part of 
crude carbolic acid. 
The presence of all sorts of rubbish affords lurking places for 
mites and decaying matter such as broken eggs attracts them par- 
ticularly. 
When fowls are moved to fresh quarters from infested quarters it 
is desirable that they be left for three days in a pen so that all mites 
will have opportunity to leave the birds. 
Mites are disseminated not only by live birds bearing them, but 
by all such articles as crates and other objects that have been in 
poultry houses. The introduction of mites by pigeons or sparrows is 
quite possible. 
Infestation of man. People in close contact with infested hen 
roosts are liable to be attacked by the mites. They cause an 
ephemeral itching lesion on the back of the hand and other exposed 
portions of the body. However, they may affect any portion of the 
body. 
Occurrence on horses. When poultry roosting quarters are near 
or in the stable, horses are subject to infestation. They cause severe 
pruritis during the night. The mites cause the formation of small 
vesicles single and grouped together. These vesicles are rubbed off, 
accompanied by depilation, but the areas soon become covered with 
new epithelium. This gives the skin a characteristic flea-bitten ap- 
pearance. To these changes are added others resulting from ex- 
cessive rubbing. 
Mites in the external ear. Mites have been observed in the 
outer ear of chickens and ducks. In the case of the latter, unusual 
movements of the head occurred. The mites were considered by the 
observer to be D. galline but Neumann expresses doubt concerning 
the identification. 
HARVEST MITES 
Harvest mites are first stage larvee of certain species of the genus 
Trombidium. They are commonly known as chiggers, a name which 
is evidently a corruption of the term chigoe, used to designate a 
species of flea. The harvest mites attack a wide variety of hosts, 
including poultry. They attach themselves in groups to the skin 
beneath the wings and on the breast and neck. Their presence causes 
areas of severe irritation and suppuration. Young chickens are most 
susceptible and their death has been attributed to the result of the 
presence of the parasites. 
Mites occur in a wide variety of places such as in damp locations 
