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Wētā (also spelled weta in English) is the
common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...
for a group of about 100
insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...
species in the families
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 Australia and South Africa, an ...
and
Rhaphidophoridae The orthopteran family Rhaphidophoridae of the suborder Ensifera has a worldwide distribution. Common names for these insects include cave crickets, camel crickets, spider crickets (sometimes shortened to "criders" or "sprickets"), and sand trea ...
endemic Endemism is the state of a species being found only 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 foun ...
to
New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
. They are giant
flightless Flightless birds are birds that cannot fly, as they have, through evolution, lost the ability to. There are over 60 extant species, including the well-known ratites ( ostriches, emus, cassowaries, rheas, and kiwis) and penguins. The smal ...
crickets Crickets are orthopteran insects which are related to bush crickets and more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 886 ...
, and some are among the heaviest insects in the world. Generally
nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...
, most small species are
carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...
s and
scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...
s while the larger species are
herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...
. Although some endemic birds (and
tuatara The tuatara (''Sphenodon punctatus'') is a species of reptile endemic to New Zealand. Despite its close resemblance to lizards, it is actually the only extant member of a distinct lineage, the previously highly diverse order Rhynchocephal ...
) likely prey on them, wētā are disproportionately preyed upon by introduced mammals, and some species are now
critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...
.


Name

Wētā is a
loanword A loanword (also a loan word, loan-word) is a word at least partly assimilated from one language (the donor language) into another language (the recipient or target language), through the process of borrowing. Borrowing is a metaphorical term t ...
, from the Māori-language word , which refers to this whole group of large insects; some types of wētā have a specific Māori name. In
New Zealand English New Zealand English (NZE) is the variant of the English language spoken and written by most English-speaking New Zealanders. Its language code in ISO and Internet standards is en-NZ. It is the first language of the majority of the populati ...
, it is spelled either "weta" or "wētā". The form with macrons is increasingly common in formal writing, as the Māori word (without macrons) instead means "excrement". Words of Māori origin in New Zealand English are both singular and plural.


General characteristics

Many wētā are large by insect standards and some species are among the largest and heaviest in the world. Their physical appearance is like a
katydid Insects in the family Tettigoniidae are commonly called katydids (especially in North America) or bush crickets. They have previously been known as "long-horned grasshoppers". More than 8,000 species are known. Part of the suborder Ensifera, the ...
, long-horned grasshopper, or
cricket Cricket is a Bat-and-ball games, bat-and-ball game played between two Sports team, teams of eleven players on a cricket field, field, at the centre of which is a cricket pitch, pitch with a wicket at each end, each comprising two Bail (cr ...
, but the hind legs are enlarged and usually very spiny. Many are wingless. Because they can cope with variations in temperature, wētā are found in a variety of environments, including alpine, forests, grasslands, caves, shrub lands and urban gardens. They are
nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...
, and all New Zealand species are flightless but closely related to winged species in
Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
. Different species have different diets. Most wētā are predators or omnivores preying on other invertebrates, but the tree and giant wētā eat mostly lichens, leaves, flowers, seed-heads, and fruit. Male
giant wētā Giant wētā are several species of wētā in the genus ''Deinacrida'' of the family Anostostomatidae. Giant wētā are endemic to New Zealand and all but one species are protected by law because they are considered at risk of extinction. The ...
(''Deinacrida'' spp.) are smaller than females and they show
scramble competition In ecology, scramble competition (or complete symmetric competition or exploitation competition) refers to a situation in which a resource is accessible to all competitors (that is, it is not monopolizable by an individual or group). However, sin ...
for mates.
Tree wētā Tree wētā (pūtangatanga) are insects in the genus ''Hemideina'' of the family (biology), family Anostostomatidae. The genus is endemic (ecology), endemic to New Zealand. There are seven species within the wētā genus ''Hemideina'', found th ...
(''Hemideina'' spp.) males have larger heads than females and a
polygynandrous Polygynandry is a mating system in which both males and females have multiple mating partners during a breeding season. In sexually reproducing diploid animals, different mating strategies are employed by males and females, because the cost of gam ...
mating system with
harem A harem is a domestic space that is reserved for the women of the house in a Muslim family. A harem may house a man's wife or wives, their pre-pubescent male children, unmarried daughters, female domestic Domestic worker, servants, and other un ...
formation and male-male competition for mates. Ground wētā (''Hemiandrus'' spp.) males provide nuptial food gifts when mating and females of some species provide maternal care. Wētā eggs are laid in soil over the autumn and winter months and hatch the following spring. A wētā takes between one and two years to reach adulthood, and over this time will have to shed its skin around ten times as it grows. Wētā can bite with powerful mandibles. Tree wētā bites are painful but not particularly common. Tree wētā lift their hind legs in a defence displays to look large and spiky, but they tend to retreat if given the chance. Tree wētā raise their hind legs into the air in warning to foes, and then bring them down to stridulate. Pegs or ridges on the side of their abdomen are struck by a patch of fine pegs at the inner surface of their hind legs (
femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...
) and this action makes a distinctive sound. These actions are also used in defence of a gallery by competing males. The female wētā looks as if she has a stinger, but it is an ovipositor, which enables her to lay eggs inside rotting or mossy wood or soil. Some species of '' Hemiandrus'' have very short ovipositors, related perhaps to their burrowing into soil and laying their eggs in a special chamber at the end of the burrow.


Taxonomy and evolution

Fossilised orthopterans have been found in Russia, China, South Africa, Australia, and New Zealand, but the relationships are open to different interpretations by scientists. Most wētā of both families are found in the Southern Hemisphere. Wētā were probably present in ancient
Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
before
Zealandia Zealandia (pronounced ), also known as (Māori language, Māori) or Tasmantis (from Tasman Sea), is an almost entirely submerged continent, submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83 ...
separated from it.
Rhaphidophoridae The orthopteran family Rhaphidophoridae of the suborder Ensifera has a worldwide distribution. Common names for these insects include cave crickets, camel crickets, spider crickets (sometimes shortened to "criders" or "sprickets"), and sand trea ...
dispersed over sea to colonise the
Chatham Islands The Chatham Islands ( ; Moriori language, Moriori: , 'Misty Sun'; ) are an archipelago in the Pacific Ocean about east of New Zealand's South Island, administered as part of New Zealand, and consisting of about 10 islands within an approxima ...
(Rēkohu), the
Auckland Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...
(Motu Maha), Snares (Tini Heke), Bounty (Moutere Hauiri) and Campbell (Motu Ihupuku) Islands. The present species might have resulted from a recent radiation, which conflicts with those earlier ideas about dispersal of wētā forebears around the Southern Hemisphere (Wallis ''et al.'' 2000). Giant, tree, ground, and tusked wētā are all members of the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
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 Australia and South Africa, an ...
(formerly in the Stenopelmatidae, but recently separated). Cave wētā are better referred to as ''tokoriro'', since they are members of the family
Rhaphidophoridae The orthopteran family Rhaphidophoridae of the suborder Ensifera has a worldwide distribution. Common names for these insects include cave crickets, camel crickets, spider crickets (sometimes shortened to "criders" or "sprickets"), and sand trea ...
, called cave crickets or camel crickets elsewhere, in a different
ensifera Ensifera is a Order (biology), suborder of insects that includes the various types of crickets and their allies, including cricket (insect), true crickets, Rhaphidophoridae, camel crickets, Tettigoniidae, bush crickets or katydids, Prophalangops ...
n superfamily. In New Zealand there were as of 2014 19 genera of tokoriri, and their taxonomy is under review. Seven new species of South Island cave wētā were named and described in 2019, including ''Pleioplectron rodmorrisi''.


Species


Giant wētā

The 11 species of giant wētā (''Deinacrida'' spp.) are endemic to New Zealand and legally protected. Giant wētā (''wētā punga'' in Māori) are large by insect standards. They are heavy herbivorous Orthoptera with a body length of up to , excluding their long legs and antennae, and weigh about 20–30 g. A captive giant wētā (''Deinacrida heteracantha'') filled with eggs reached a record 70 g, making it one of the heaviest documented insects in the world and heavier than a sparrow. The largest species of giant wētā is the Little Barrier Island wētā, also known as the wētāpunga. Giant wētā tend to be less social and more passive than tree wētā (''Hemideina'' spp.). They are classified in the
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
'' Deinacrida'', which is Greek for "terrible grasshopper". They are found primarily on small islands off the coast of the main islands or at high elevation on New Zealand's
South Island The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...
(e.g. the alpine scree wētā '' D. connectens''), and are sometimes considered examples of
island gigantism Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general "is ...
.


Tree wētā

Tree wētā ('' Hemideina'') are commonly encountered in suburban settings in New Zealand's
North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...
. They are up to 40 mm long and most commonly live in holes in trees formed by beetle and moth larvae or where rot has set in after a twig has broken off. The hole, called a gallery, is maintained by the wētā and any growth of the bark surrounding the opening is chewed away. They readily occupy a preformed gallery in a piece of wood (a "wētā motel") and can be kept in a suburban garden as pets. A gallery might house a harem of up to 10 adult females and one male. Tree wētā are nocturnal. Their diet consists of plants and small insects. The males have much larger jaws than the females, though both sexes will stridulate and bite when threatened. The seven species of tree wētā (''pūtangatanga'' in Māori) are: *The Auckland tree wētā '' Hemideina thoracica'' can be found throughout the
North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...
apart from the
Wellington Wellington is the capital city of New Zealand. It is located at the south-western tip of the North Island, between Cook Strait and the Remutaka Range. Wellington is the third-largest city in New Zealand (second largest in the North Island ...
-
Wairarapa The Wairarapa (; ), a geographical region of New Zealand, lies in the south-eastern corner of the North Island, east of metropolitan Wellington and south-west of the Hawke's Bay Region. It is lightly populated, having several rural service t ...
region. Within this range are seven chromosome races. *The Wellington tree wētā ''
Hemideina crassidens ''Hemideina crassidens'', commonly known as the Wellington tree wētā, is a large, flightless, nocturnal insect in the family Anostostomatidae. This wētā species is Endemism, endemic to New Zealand and populates regions in the southern half ...
'' occupies Wellington, the Wairarapa, the northern parts of the
South Island The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...
, and the West Coast. *'' Hemideina trewicki'' is found in
Hawke's Bay Hawke's Bay () is a region on the east coast of New Zealand's North Island. The region is named for Hawke Bay, which was named in honour of Edward Hawke. The region's main centres are the cities of Napier and Hastings, while the more rural ...
. *'' H. femorata'' is found in Marlborough and
Canterbury Canterbury (, ) is a City status in the United Kingdom, city and UNESCO World Heritage Site, in the county of Kent, England; it was a county borough until 1974. It lies on the River Stour, Kent, River Stour. The city has a mild oceanic climat ...
. *The rare '' H. ricta'' species occurs in Banks Peninsula. *The West Coast bush wētā '' H. broughi'' largely overlaps with the Wellington tree wētā in Nelson and the northern portion of the West Coast. *'' H. maori'', the mountain stone wētā, lives above the tree line in the
Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) are a mountain range extending along much of the length of New Zealand, New Zealand's South Island, reaching its greatest elevations near the range's western side. The n ...
. The North Island species each have a distinctive set of chromosomes (
karyotype A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...
). When the territories of species overlap, as with the related species ''H. femorata'' and ''H. ricta'' on Banks Peninsula, they may interbreed, although offspring are sterile.


Tusked wētā

Tusked wētā are characterised by long, curved tusks projecting forward from the male's mandibles. The tusks are used in male-to-male combat, not for biting. Female tusked wētā look similar to ground wētā. Tusked wētā are mainly carnivorous, eating worms and insects. There are three known species in two different subfamilies: the Northland tusked wētā '' Anisoura nicobarica'' (originally described as a ground wētā, ''Hemiandrus monstrosus''), in the subfamily Deinacridinae; the Mercury Islands tusked wētā '' Motuweta isolata''; and the most recently discovered, the Raukumara tusked wētā '' Motuweta riparia''. ''Motuweta'' is in the same subfamily as ground wētā, Anostostomatinae. The Northland tusked wētā lives in tree holes, similar to tree wētā. The
Mercury Islands The Mercury Islands are a group of seven islands off the northeast coast of New Zealand's North Island. They are located off the coast of the Coromandel Peninsula, and northeast of the town of Whitianga. History Great Mercury Island (Ahu ...
or Middle Island tusked wētā was discovered in 1970. It is a ground-dwelling wētā, entombing itself in shallow burrows during the day, and is critically endangered: a Department of Conservation breeding programme has established new colonies on other islands in the Mercury group. The Raukumara tusked wētā was discovered in 1996, in the Raukumara Range near the
Bay of Plenty The Bay of Plenty () is a large bight (geography), bight along the northern coast of New Zealand's North Island. It stretches from the Coromandel Peninsula in the west to Cape Runaway in the east. Called ''Te Moana-a-Toitehuatahi'' (the Ocean ...
. It has the unusual habit of diving into streams and hiding underwater for up to three minutes if threatened.


Ground wētā

Ground wētā are classified in to the two genera '' Hemiandrus'' and '' Anderus''. The species in these two genera are each more closely related to winged Australian species than they are two each other. About 30 species of ground wētā occur in New Zealand, and several similar (undescribed) species are found in Australia. They are also very like the Californian '' Cnemotettix''—a similarity perhaps due to their very similar habits and habitat. 19 ''Hemiandrus'' species have been described from New Zealand and other distinct populations require further study. They hide in burrows in the ground during the day, and those that live in open ground (e.g., '' H. focalis'', '' H. maia'') conceal their exit holes with a specially made perforated door. During the night, ground wētā hunt invertebrate prey and eat fruit. Most female ground wētā have long ovipositers (e.g. '' H. maculifrons''), but some have short ovipositers and maternal care (e.g. ''H. maia, H. pallitarsis'').


Cave wētā

The 60 species of cave wētā or ''tokoriro'' are only very distant relatives of the other types of wētā, being classified in several genera of subfamily Macropathinae in family
Rhaphidophoridae The orthopteran family Rhaphidophoridae of the suborder Ensifera has a worldwide distribution. Common names for these insects include cave crickets, camel crickets, spider crickets (sometimes shortened to "criders" or "sprickets"), and sand trea ...
. They have extra-long antennae, and may have long, slender legs and a passive demeanour. Although they have no hearing organs on their front legs like species of ''Hemideina'' and ''Deinacrida'', some (such as '' Talitropsis'') are very sensitive to ground vibrations sensed through pads on their feet. Specialised hairs on the cerci and organs on the antennae are also sensitive to low-frequency vibrations in the air. Although some do live in caves, most species (e.g. '' Talitropsis sedilloti'') live in the forest among
leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall, or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that has fallen to the ground. This detritus or dead organic material and its constituen ...
, logs, under bark (e.g. '' Isoplectron''), inside tree holes (e.g. '' Neonetus'' sp.) and amongst rocks in the mountains (e.g. '' Pharmacus''). Cave-dwelling species may be active within the confines of their caves during the daytime, and those individuals close to cave entrances venture outside at night. File:weta2.jpg, Face File:weta3.jpg, Lower leg (tarsus) with two claws and sensory pads File:weta4.jpg, Upper leg File:weta5.jpg, Underside with parasites


Conservation

Although wētā had native predators in the form of birds (especially the
weka The weka, also known as the Māori hen or woodhen (''Gallirallus australis'') is a flightless bird species of the rail family. It is endemic to New Zealand. Some authorities consider it as the only extant member of the genus '' Gallirallus''. ...
and kiwi), reptiles, and bats before the arrival of humans, introduced species such as cats, hedgehogs, rats (including kiore) and mustelids have caused a sharp increase in the rate of predation. They are also vulnerable to habitat destruction caused by humans and modification of their habitat caused by introduced browsers. New Zealand's Department of Conservation considers 16 of the over 100 species at risk. Programmes to prevent extinctions have been implemented since the 1970s. Some especially endangered species are tracked by radio beacons.


In popular culture

New Zealanders
Peter Jackson Sir Peter Robert Jackson (born 31 October 1961) is a New Zealand filmmaker. He is best known as the director, writer, and producer of the ''Lord of the Rings'' trilogy (2001–2003) and the ''Hobbit'' trilogy (2012–2014), both of which ar ...
, Richard Taylor, and
Jamie Selkirk James William Arthur "Jamie" Selkirk is a film editor and Film producer, producer who has worked primarily in New Zealand. He is particularly noted for his work on The Lord of the Rings (film series), ''The Lord of the Rings'' film trilogy, which h ...
founded visual effects company Weta Digital (now known as Wētā FX), naming it after the insect. One of Jackson's films, ''
King Kong King Kong, also referred to simply as Kong, is a fictional giant monster resembling a gorilla, who has appeared in various media since 1933. The character has since become an international pop culture icon,Erb, Cynthia, 1998, ''Tracking Kin ...
'', has among the Skull Island fauna oversized versions of the giant wētās, referred to with the scientific name "Deinacrida rex" or "Wētā-rex".


References


Further reading

* * * * *Ramløv, H. (2000) Aspects of cold tolerance in ectothermic animals. ''Journal of Human Reproduction''. 15 (Suppl. 5): 26–46.


External links


Wētā
at the
New Zealand Department of Conservation The Department of Conservation (DOC; Māori language, 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 ...

''Wētā''
in Te Ara: The Encyclopedia of New Zealand
Wētā Geta
– a comprehensive guide to New Zealand Orthoptera {{Authority control Insect common names Endemic insects of New Zealand