(4) Isle of Wight Disease in Hive Bees—Acarine Disease: The Organism associated with the Disease — Tarsonemus woodi, n. sp.

Abstract

The organism which has been found living in the anterior tracheal system of hive bees, and whose presence is associated with Isle of Wight disease, I have identified as a hitherto undescribed species of the genus Tarsonemus. This genus was founded in 1876 by Canestrini and Fanzago, and since then a moderate number only of species has been established. The true systematic position of these Acarines has been much in doubt, and their position in the order has from time to time been revised. Canestrini (1888) constituted the Tarsonemes the type of a special family, the Tarsonemini; they have been associated with the Oribatidæ by Berlese, and with the Cheyletidæ by Trouessart (1892). Banks (1904) regarded them as showing resemblances to the Tyroglyphidse, and placed them in a super-family Sarcoptoidea. An important character of the Tarsonemes is the existence of a tracheal system in the adult female, which is not found in the male nor in any pre-adult stage of either sex. This feature was adopted by Berlese (1897) as the basis of his sub-order, Heterostigmata, and by Oudemans (1906) in his division Trachelostigmata. This super-family includes two families—Tarsonemidæ and Scutacaridæ (Oudemans, 1916). This last is the Disparipedidae of Berlese.