Occurrence of Rhinonyssus rhinolethrum (Trouessart, 1895) (Acarina: Rhinonyssidae), a nasal mite in fulvous whistling duck Dendrocygna bicolor (Vieillot, 1816) and white-faced whistling-duck Dendrocygna viduata (Linnaeus, 1766) in Southern Brazil

ABSTRACT: The authors report the occurrence of the nasal mite Rhinonyssus rhinolethrum (Trouessart, 1895) (Acarina: Rhinonyssidae) in free-living fulvous whistling duck Dendrocygna bicolor (Vieillot, 1816) and white-faced whistling-duck Dendrocygna viduata (Linnaeus, 1766) in the Rio Grande do Sul region, Southern Brazil. Prevalence and mean intensity showed values of 35.5% and 2.27 mites to D. bicolor and 13% and 9.33 mites for D. viduatta . The intensity of parasitism ranged from 1 to 6 mites in D. bicolor , and 1 to 22 mites in D. viduatta . This is the first report of R. rhinolethrum on D. bicolor and D. viduata in Rio Grande do Sul, expanding the list of anatids parasitized by this species in this State.