Comparison of external morphology of tritonymphs in myobiid mites (Myobiidae) associated with marsupials (Marsupialia)

Abstract

The external morphology of tritonymphs in myobiids of the subfamilies Archemyobiinae Fain, 1973 (Archemyobia Jameson, 1955, Caenolestomyobia Bochkov & OConnor, 2009, and Dromicimyobia Fain, 1973), Australomyobiinae Fain, 1973 (Australomyobia Fain, 1973, and Acrobatobia Fain & Lukoschus, 1976), and Xenomyobiinae Fain & Likoschus, 1977 (Xenomyobia Fain & Lukoschus, 1977) (Prostigmata: Myobioidea: Myobiidae) associated with marsupials (Marsupialia) is examined. Eleven from sixteen known species of the marsupial-associated myobiids belonging to all six known genera are examined. In tritonymphs of the subfamily Australomyobiinae, setae 4b are absent and palpal setae are present. This last state could be a symplesiomorphy or synapomorphy (reversion). Tritonymphs of the subfamily Xenomyobiinae are characterized by the following derived states: relatively short setae h1, absence of setae dTa and vTa, vʹ and vʺ of tibiae II and III, lʹ of trochanter I, 1c, 2b, and one-segmented legs IV without claws. Tritonymphs of the subfamily Archemyobiinae have no obvious unique synapomorphies. A generic key to tritonymphs of marsupial-associated myobiids is given for the first time.