Please watch this short video by Prof. Stephen Barker, author of this website, as he offers a welcome and an explanation of the site’s overarching purpose
Australasia has a special place in the history of hard ticks (Ixodidae). Indeed, the hard ticks (Dobson & Barker 1999; Barker & Murrell 2002, 2004; Barker et al. 2021), soft ticks and nutalliellid ticks (Barker & Walker 2014) may have first lived in Australia, or more accurately, that part of the super continent Gondwana that became Australia, perhaps as early as 362-409 million years ago in the Devonian era. Accordingly, six of the eight subfamilies of ticks are endemic to Australia: Argasinae, Bothriocrotinae, Amblyomminae, Haemaphysalinae, Ixodinae and the Ornithodorinae.
Only the subfamilies Nutalliellinae (the nutalliellid ticks) and Rhipicephalinae are not endemic to Australia. We speculate that the Nutalliellinae may well have lived in Australia (Barker et al. 2014), or might still be here, but certainly the Rhipicephalinae evolved elsewhere (probably in Africa) and much, much later (Murrell et al. 2001a). Whereas the Australian tick fauna is rich in subfamilies, it is depauperate in species: only 72 of the 900 or so species of ticks of the world are endemic to Australia.
Furthermore, the earliest diverging lineage of the subfamily Ixodinae, the Australasian Ixodes clade, is endemic to Australasia (Barker & Murrell 2004). The closest living relatives to the ticks, the sister-group, seems to be the free-living holothyrid mites (Murrell et al. 2005 and references therein). Two hypotheses have been proposed: (i) an ancient origin (c. 390 m. y. a.) and vicariant dispersal during continental breakup (Dobson & Barker 1999); or (ii) recent origin (c.120 m. y. a.) and dispersal after the breakup of continents was almost complete (Klompen et al. 2000).
In our monograph ‘Barker & Barker, 2023‘ we advocate a simple two-step process for identifying the ticks of Australasia. The first step leads to the name of the genus to which a tick belongs, e.g. Ixodes, and its sex. The second step identifies the tick at the species level, e.g. Ixodes holocyclus, the eastern paralysis tick. These steps involve simple visual-matching of specimens to the photographs and drawings, whilst examining the tick with a dissecting microscope or hand lens.
The first part of this monograph explains how to identify the ticks of Australasia: it includes a glossary of the morphological and technical terms used to define the different genera and species of ticks (this is a slightly updated version of the glossary of Barker & Walker (2014) which Alan Walker wrote; reproduce with permission, Magnolia Press). The glossary is placed first because it is essential for the identification process and it is easiest to find here.
This enables us at the University of Queensland to screen the ticks in your area for potentially pathogenic Rickettsiales bacteria like Ehrlichia canis and its kin.