| abstract | A new species is described of a dermanyssid mite, genus Ichoronyssus Kolenati, found on a heavily infested white mouse, Mus musculus, var. albinus. The new species, I. butantanensis, may be characterized as follows:
Description of the female
Lenght, 0mm.67; width, 0mm.33 at the level of leg IV. Shape elliptical, colour, by naked eye, yellowish white. Scarcely setous body, with striated soft tegument.
Ventral side - Sternal plate about five times as broad as long, lying between second coxae; posterior margin deeply concave; angles well pronounced, anterior ones slender; six paired setae in two straight antero-posterior rows; first pair of sternal setae directly on front margin and next to median line; median pair at some distance from lateral margins; posterior pair marginal, at posterior projections of sternal plate.
Genito-ventral plate - Very broad, especially at posterior end, narrower at level of coxae IV; posterior extremty broadly rounded at a considerable distance of anal plate; one pair of sub-marginal setae, as long as sternal one, at level of coxae IV.
Anal plate - Piriform, anus near front margin; paired setae smaller than posterior one, a little behind middle of anal aperture, halfway between rim of anus and lateral margins of anal plate; posterior seta a little over its lenght from posterior margin of anus; setae smaller than those of other plates.
Stigmata at level of posterior margin of coxae III. Peritremata visible from middle of coxae IV to front margin of coxa I.
Legs I and IV longest. Coxa III with a stout spine, coxa II with a smaller and coxa IV with a very small spine. Femora I and II with two spine-like setae. Tibia I slightly longer than wide; tibia II as long as wide.
Dorsal side - Shield covering most of cephalothorax and part of abdomen, with lateral margins parallel in front, with a depression at level of III legs and converging from behind leg IV to level of middle of anal plate, with a broad distal end, scarcely setous, with about 24 sub-marginal setae.
Habitat - Found swarming on Mus musculus, var. albinus.
Patria - S. Paulo
Holotye and Paratypes - All in the collection of the Institut Butantan. |