Description of a new Pavlovskyella species (Acari: Argasidae) from Chile

Abstract

Soft ticks (Argasidae) of the Pavlovskyella Pospelova-Shtrom subgenus are important vectors of relapsing fever spirochetes, which are agents of disease globally. South American representatives of the Pavlovskyella subgenus include 3 species: Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, and Ornithodoros (Pavlovskyella) rostratus Aragão. Here, we describe a fourth species based on morphological and mitogenomic evidence of ticks collected in burrows of unknown hosts in central Chile. The larva of the new species separates from other South American soft ticks by the following combination of characters: 13 pairs of dorsolateral setae, dorsal plate hexagonal, hypostome blunt with denticles from apex almost to the base. Adults of this new species lack cheeks, possess a dorsoventral groove, and have humps, similar to O. (P.) brasiliensis; however, they lack bulging structures on the flanks of idiosoma. Moreover, females and males differ from O. (P.) rostratus by having 3 humps instead of spurs in tarsi I and from O. (P.) furcosus because of their smaller size and thinner anterior lip of the genital aperture in females. The phylogenetic analysis performed with mitogenomes of the Argasidae family depicts the new Pavlovskyella species from Chile in a monophyletic clade with other South American species in the subgenus, confirming a regional group.

Noteworthy records of the ticks Ornithodoros rostratus and Amblyomma sculptum parasitizing Pteronura brasiliensis in the central-western region of Brazil, with pathogen investigation notes

“…In addition, O. rostratus, along with Ornithodoros brasiliensis Aragão, 1923, Ornithodoros furcosus Neumann, 1908, and the recently described species Ornithodoros improvisus Muñoz-Leal & Venzal, 2023, form the neotropical group of the Pavlovskyella subgenus. Ornithodoros brasiliensis is endemic to southern Brazil, while O. furcosus occurs in the higher-altitude Andean parts of Ecuador, Colombia and Peru, and O. improvisus occurs in Chile (Muñoz-Leal et al, 2023). The Pavlovskyella species can be found in their hosts' burrows due to their habit of living buried in sand or soft soil near their principal hosts' habitats.…”

“…Ornithodoros rostratus Aragão, 1911, is an argasid tick species reported in Brazil, Paraguay, Argentina, and Bolivia. This species belongs to the subgenus Ornithodoros ( Pavlovskyella ) Pospelova-Shtrom, 1950, a paraphyletic group of 4 clades and more than 17 species ( Mans et al, 2019 ; Muñoz-Leal et al, 2023 ).…”