Ground weta are classified in the genus Hemiandrus. Currently there are 17 described species of ground wētā in New Zealand and additional species remain to be described. Also, some species in Australia appear to belong to this group but have not been formally described yet.
All species hide in burrows in the ground during the day and those that live in open ground (e.g. H. focalis) conceal the exit hole with a specially made perforated door. During the night ground wētā emerge to hunt or scavenge invertebrate prey and eat fruit. Ground wētā do not have ears like those of tree wētā on their forelegs, but they do use vibration signals to attract mates.
Although broadly similar in appearance, adult females in particular fall into distinct groups in terms of their ovipositor (egg laying tube) length; some have almost invisible short blunt overipositors (e.g. H. pallitarsus) while others have long curved sharp ovipositors (e.g. H. brucei), and a few species have a short, stumpy but visible ovipositor (e.g. H. maia). Overall size also varies with the largest species associated with elevated, southern habitats (e.g. H. focalis). The larger species tend to have bolder patterns and more colour, compared to the smaller, forest-dwelling species that are ochreous brown to black.
Hemiandrus bilobatus Ander 1938; H. brucei Taylor-Smith, Trewick & MorganRichards 2016; H. celaeno Trewick, Taylor-Smith & Morgan-Richards 2020; H. electra Taylor-Smith, Morgan-Richards & Trewick 2013; H. fiordensis (Salmon, 1950); H. focalis (Hutton, 1896); H. luna Taylor-Smith, Trewick & Morgan-Richards 2016; H. maculifrons (Walker, 1869) (see Taylor-Smith et al. 2013); H. maia Taylor-Smith, Morgan-Richards & Trewick 2013; H. merope Trewick, Taylor-Smith & Morgan-Richards 2020; H. nitaweta Jewell 2007; H. nox Taylor-Smith, Trewick & Morgan-Richards 2016; H. pallitarsis (Walker, 1871) (See Trewick et al. 2020); H. sterope Trewick, Taylor-Smith & Morgan-Richards 2020; H. subantarcticus (Salmon, 1950); H. superba Jewell 2007; H. taygete Trewick, Taylor-Smith & Morgan-Richards 2020; H. jacinda, Trewick 2021. Hemiandrus anomalus Salmon, 1950 is junior synonym of H. bilobatus judging by characters of the male holotype, the female type is a juvenile and not diagnosable. H. lanceolatus (Walker, 1869) is represented by a juvenile specimen (Johns 2001) and is best considered nomen nudum. H. similis Ander, 1938 is a synonym of H. pallitarsis (Trewick et al. 2020).