Description of a new soft tick species (Acari: Argasidae: Ornithodoros) parasite of Octodon degus (Rodentia: Octodontidae) in northern Chile

MUÑOZ-LEAL S, VENZAL JM, NAVA S, MARCILI A, GONZÁLEZ-ACUÑA D, MARTINS TF, LABRUNA MB.

Ticks and Tick-borne Diseases

Elsevier

Año: 2020 vol. 11

A new argasid (Argasidae) tick is herein described based on morphology and molecular data obtained fromlarvae parasitizing Octodon degus and from ticks collected inside burrows in northern Chile. Unfed laboratoryrearedlarvae were mounted in slides for morphometrical and morphological analyses. Larvae of Ornithodorosoctodontus n. sp. share morphological traits with Ornithodoros quilinensis and Ornithodoros xerophylus, two speciesassociated with rodents in the Argentinean Chaco. However, a longer hypostome with two rows of 21 and 22denticles each one, and conspicuous leaf-shaped anal plates separate O. octodontus. While nymphal stages of O.octodontus lack cheeks and possess a micromammillated dorsal integument, adults have cheeks and exhibitmarkedly irregular mammillae along their dorsal surface. Phylogenetic analyses of neotropical Argasidae basedon mitochondrial 16S rDNA sequences point that O. octodontus forms a monophyletic group with O. xerophylusand an unidentified Ornithodoros sp. from Bolivia, all of them associated with burrow-dweller rodents.Ornithodoros aragaoi and Ornithodoros davisi, two rare species collected once only in the Peruvian Andean Plateauduring 1955 are morphologically closely related with adults and nymphs of O. octodontus. Biological observationsof O. octodontus revealed autogenic females. For the moment, subgeneric classification of this new speciesdepends on further biological studies. The fauna of ticks occurring in Chile is now represented by 22 species, 11belonging to the Argasidae family.