A review of argasid ticks and associated pathogens of China

Abstract

It has been recorded 221 species of soft ticks in the world. However, the classification system of Argasidae is still unclear with nearly two-third controversial species in genus level. Therefore, comprehensive research is still necessary. In 2016, Wen and Chen overviewed the valid species of soft ticks in China for the first time. Up to now, the soft tick fauna of China remains poorly known. Although several studies have been undertaken, the information regarding soft ticks and associated diseases are fragmentary. To facilitate the future study of this group, the scattered information on soft ticks of China is herein synthesized. Toward the end of 2021, 15 valid species of argasid ticks have been reported, of these, 9 species (60%) including Argas beijingensis, A. japonicus, A. persicus, A. sinensis, A. vespertilionis, A. vulgaris, Ornithodoros lahorensis, O. tartakovskyi, and O. papillipes have been recorded biting humans. Argas persicus is the most common species, and its borne pathogens are widely investigated, while most other argasid ticks are not sufficiently studied in China. Here, we summarize detailed information regarding hosts, geographical distribution, molecular data, and vector roles of argasid ticks in China.

The complete mitogenome of Argas vulgaris (Filippova, 1961) and its phylogenetic status in subgenus Argas (Acari: Argasidae)

“…vulgaris Fig. 5 d) ( Chen and Liu, 2022 ), the dental formula was 2|2 for the first three rows and approximately 3|3 backward (2|2 type of hypostome dental formula, and each row has 7 to 9 teeth in Ar. vulgaris Fig.…”

“…More than 221 argasid ticks have been described to date worldwide. In China, approximately 15 species from two genera were identified, including 10 species of the genus Argas and 5 species of the genus Ornithodoros ( Chen and Liu, 2022 ).…”

“…For instance, the geographical distribution and host association of Ar. vulgaris coincided with that of the species in the genus Argas , which might lead to misidentification ( Chen and Liu, 2022 ; Sun et al, 2019 ). The other subgenus Persicargas contains Ar.…”

“…persicus and Ar. robertsi , the former of which is the most common species in China ( Chen and Liu, 2022 ) may transmit a variety of pathogenic viruses ( Zahid et al, 2021 ).…”

“…It is well known that numerous argasid ticks share such a high degree of external morphological resemblance, and discerning them from one another remains difficult ( Muñoz-Leal et al, 2018 ). Currently, the higher hierarchical system of Argasidae is still argued by different classification schools and nearly two-thirds of argasid taxon species are controversial ( Chen and Liu, 2022 ). To date, the argasid ticks mentioned above have not been thoroughly studied except Ar.…”