Fig. 357.—Dermanyssus gallinæ. Enlarged. (After Berlese.)
Fig. 358.—Dermanyssus hirundinis. 40/1. (After Delafond.)
Dermanyssus hirundinis, Hermann, 1804.
Syn.: Acarus hirundinis, Herm., 1804.
Of a brownish colour, 1·2 or 1·4 mm. in length; lives in the nests of swallows and is occasionally found on man.
[The red hen mite (Dermanyssus gallinæ) not only attacks poultry and man, as stated above, but is found on all birds and many mammals. The D. gallinæ is the same as D. avium. The species found in swallows’ nests is also said to be the same. This mite can remain for weeks without any food from its normal host. They only attack man when entering or cleaning dirty and neglected fowl-houses; they do not produce a true dermatosis. They chiefly attack the backs of the hands and forearms of those who constantly attend poultry and give rise to symptoms similar to the papular eczema of scabies. That they may remain some time upon the human body we know from the following cases out of many recorded: Geber observed that the Dermanyssus had caused a diffused eczema on a woman, which lasted four weeks and then disappeared. The tique of F. V. Raspail is the bird Dermanyssus; he records children and adults being attacked not only when handling pigeons, but even when walking in a garden manured with pigeons’ dung. The affection soon disappeared when the pigeons were destroyed and the excreta buried. I have frequently heard of poultrymen being seriously attacked by this pest.—F. V. T.]
Genus. Holothyrus.
Holothyrus coccinella, Gervais, 1842.