''Hemiandrus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

wētā Wētā (also spelt weta) is the common name for a group of about 100 insect species in the families Anostostomatidae and Rhaphidophoridae endemic to New Zealand. They are giant flightless crickets, and some are among the heaviest insects in th ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Anostostomatidae Anostostomatidae is a family of insects in the order Orthoptera, widely distributed in the southern hemisphere. It is named Mimnermidae or Henicidae in some taxonomies, and common names include ''king crickets'' in South Africa and ''wētā'' i ...

. In

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

they are known as ground wētā due to their

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

ing lifestyle. ''Hemiandrus'' wētā are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, and reside in these

s during the day. Ground wētā seal the entrance of their burrow during the day with a soil plug or door so that their burrow is concealed. This genus was originally said to be distributed in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and New Zealand, however, with recent

molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

genetic methods, this is under debate. Ground wētā adults are smaller than other types of wētā, with the unusual trait of having both long and short

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

s, depending on the species. The name of this genus is said to come from this trait as hemi- mean half and -andrus means male, as the species where the female has a short ovipositor can sometimes be mistaken for a male. This genus has a diverse diet, depending on the species.

Taxonomy

The genus ''Hemiandrus'' was originally described by Kjell Ander in 1938. 10 undescribed species of this genus are said to be in Australia, however molecular analyses show that the two lineages genetically represent two separate lineages, therefore their

Australasia Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologica ...

n distribution is under debate. ''Hemiandrus'' is however the most species rich genus of the New Zealand

Morphology

The genus ''Hemiandrus'' include the smallest wētā species, with adult individual body size no more than 7

millimetre 330px, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is between 1 meter to 1 millimeter. The millimetre (American and British English spelling differences#-re, -er, ...

s, and weighing less than a

gram The gram (originally gramme; SI unit symbol g) is a Physical unit, unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure wate ...

. The largest ''Hemiandrus'' species has a body length of almost 30mm. These wētā have no tympanum, and instead are able to detect

sound In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the ...

through their

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

, which is adaptive for their underground lifestyle. Some species in this genus have unusually short

s for

Orthoptera Orthoptera () is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects, such as the bush crickets or katydids and wētā. The order is subdivided into two suborders: Caelifera – grassho ...

ns, the species with this morphological trait exhibit maternal care, which is uncommon as it occurs only in five families within the Orthoptera order.

Diet

The diet of these wētā depends on the species, where ''H. maculifrons'' is

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

, ''H. maia'' is

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

, eating fruit and

invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

. Other ground wētā species however have been shown to be mainly

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

, eating apricots and various grass species.

Distribution

* Australia (Undescribed species) * New Zealand - This genus are found throughout the

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

, and even on some of the offshore islands of New Zealand. (See distribution map http://wetageta.massey.ac.nz/Text%20files/groundweta.html). They are found in lowland forests, riverbeds, alpine herb fields, and suburban gardens. If this genus also occurs in Australia (which there is debate about), then this is the only non-

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

genus of wētā in New Zealand.

''Hemiandrus'' in New Zealand

There are approximately 14 undescribed New Zealand species of this genus, with 19 described species. These species of ''Hemiandrus'' are eaten by native species such as the wattle birds,

kiwi Kiwi most commonly refers to: * Kiwi (bird), a flightless bird native to New Zealand * Kiwi (nickname), a nickname for New Zealanders * Kiwifruit, an edible berry * Kiwi dollar or New Zealand dollar, a unit of currency Kiwi or KIWI may also refe ...

, but also by introduced species such as

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

stoat The stoat (''Mustela erminea''), also known as the Eurasian ermine, Beringian ermine and ermine, is a mustelid native to Eurasia and the northern portions of North America. Because of its wide circumpolar distribution, it is listed as Least Conc ...

s, and

hedgehogs A hedgehog is a spiny mammal of the subfamily Erinaceinae, in the eulipotyphlan family Erinaceidae. There are seventeen species of hedgehog in five genera found throughout parts of Europe, Asia, and Africa, and in New Zealand by introduction ...

. Of the described species in this genus, half have a restricted

range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...

, but most are common and widespread, and are not thought to be endangered (as per the

New Zealand Department of Conservation The Department of Conservation (DOC; Māori: ''Te Papa Atawhai'') is the public service department of New Zealand charged with the conservation of New Zealand's natural and historical heritage. An advisory body, the New Zealand Conservation Au ...

Species

* '' Hemiandrus bilobatus'' Ander, 1938 * '' Hemiandrus brucei'' Taylor Smith, Trewick & Morgan-Richards, 2016 * '' Hemiandrus celaeno'' Trewick, Taylor-Smith & Morgan-Richards 2020 * '' Hemiandrus electra'' Taylor Smith, Morgan-Richards & Trewick, 2013 * '' Hemiandrus fiordensis'' (Salmon, 1950) * '' Hemiandrus focalis'' (Hutton, 1897) *'' Hemiandrus jacinda'' Trewick, 2021 * '' Hemiandrus lanceolatus'' (Walker, 1869) * '' Hemiandrus luna'' Taylor Smith, Trewick & Morgan-Richards, 2016 * '' Hemiandrus maculifrons'' (Walker, 1869) * '' Hemiandrus maia'' Taylor Smith, Morgan-Richards & Trewick, 2013 * '' Hemiandrus merope'' Trewick, Taylor-Smith & Morgan-Richards 2020 * ''

Hemiandrus nitaweta ''Hemiandrus'' is a genus of wētā in the family Anostostomatidae. In New Zealand they are known as ground wētā due to their burrowing lifestyle. ''Hemiandrus'' wētā are nocturnal, and reside in these burrows during the day. Ground wētā s ...

'' Jewell, 2007 * ''

Hemiandrus nox ''Hemiandrus nox'', the night ground wētā, is a species of ground wētā endemic to New Zealand. During the day, this wētā hides in burrows in the soil and is active only at night (they are nocturnal). The species is found in native forests ...

'' Taylor Smith, Trewick & Morgan-Richards, 2016 * '' Hemiandrus pallitarsis'' (Walker, 1869) * '' Hemiandrus sterope'' Trewick, Taylor-Smith & Morgan-Richards 2020 * '' Hemiandrus subantarcticus'' (Salmon, 1950) * '' Hemiandrus superba'' Jewell, 2007 * '' Hemiandrus taygete'' Trewick, Taylor-Smith & Morgan-Richards 2020 Possibly also: * ''Hemiandrus monstrosus'' Salmon, 1950 (listed as valid in the Orthoptera Species File, as a synonym by other secondary sources)

References

External links

iNaturalist

{{Taxonbar, from=Q5711390 Weta Anostostomatidae Ensifera genera