A new species of Androlaelaps Berlese, 1903 (Acari: Parasitiformes) parasitising an akodontine rodent (Cricetidae: Sigmodontinae) in northeastern Argentina.

Androlaelaps misionalis, a new species of laelapine mite, is described on the basis of specimens collected from the pelage of the akodontine rodent Akodon montensis Thomas at Salto El Paraíso, Misiones Province, in northeastern Argentina. The formal taxonomic description, illustrations and SEM photographs are derived from female specimens; the male and nymph are unknown. Androlaelaps misionalis n. sp. resembles A. maurii Lareschi & Gettinger, 2009 in general appearance, and both species are close to A. rotundus Fonseca, 1936. The former two differ from A. rotundus in their smaller size, by having the distance between the j6 setae similar to the distance between the z5 setae, and by having an opisthogaster with a pair of setae closer to the epigynal shield. A. misionalis differs from A. maurii mainly in its: larger dorsal shield (length >500 mum); sternal setae S1, S2 and S3 with tips not extending beyond the following setal base; sternal shield width >1.5 times its length; and shorter epigynal seta S5. This mite appears to be host-specific to Akodon montensis.