Argasidae


The Argasidae are the family of soft ticks, one of the three families of extant ticks. The family contains 220 species, although the composition of the genera is less certain, and more study is needed before the taxonomy is resolved. The Argasidae are very common in South Asia, along with around 100 other species of ticks from other lineages, making South Asia the region with the highest biodiversity of ticks worldwide. Soft ticks are resistant to desiccation and can live for several years in arid conditions.

Physical characteristics

Soft ticks lack the hard scutum present in the hard ticks. The gnathosoma is located on the underside of the animal's body and is not readily visible, while in the Ixodidae, the gnathosoma projects forward from the body. The lateral edges of the body are rounded.

Systematics

Argasid systematics remain in flux. There have been as many as four major conflicting taxonomic 'schools' over time, which all conflict in some way with contemporary molecular phylogenies. As such, there is an ongoing research effort to align finds from molecular systematics with pre-existing morphological based species constructs. As of 2025, the most up-to-date classification scheme and species list follows from Mans et al., comprising 220 taxa in 17 genera:

GeneraSubgenera# spp.
Alveonasus Neumann, 19087
Argas Latreille, 179544
Navis Mans et al., 20191
Ogadenus Neumann, 19071
Proknekalia Keirans et al., 19773
Secretargas Hoogstraal, 19573
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