tree wētā
{{Short description|Genus of orthopteran insects}}
{{en-NZ|date=February 2019}}
{{Automatic taxobox
|name=Tree wētā
|image=Male tree weta-orig.jpg
|image_caption=Male Wellington tree wētā, Hemideina crassidens
|taxon=Hemideina
|authority=Walker, 1869[http://orthoptera.speciesfile.org/Common/basic/Taxa.aspx?TaxonNameID=1132046 Hemideina at OSF]
|subdivision_ranks=Species
|subdivision=See text.
}}
Tree wētā (pūtangatanga) are insects in the genus Hemideina of the family Anostostomatidae. The genus is endemic to New Zealand.{{Cite journal|last=Pratt|first=Renae C|last2=Morgan-Richards|first2=Mary|last3=Trewick|first3=Steve A|date=2008|title=Diversification of New Zealand weta (Orthoptera: Ensifera: Anostostomatidae) and their relationships in Australasia|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=363|issue=1508|pages=3427–3437|doi=10.1098/rstb.2008.0112|issn=0962-8436|pmc=2607373|pmid=18782727}} There are seven species within the wētā genus Hemideina, found throughout the country except lowland Otago and Southland.{{Cite web|url=https://teara.govt.nz/en/weta/page-2|title=Wētā – Tree Wētā|last=Gibbs|first=George|website=Te Ara, Encyclopedia of New Zealand|language=en|access-date=2019-01-27}} Because many pūtangatanga species are common and widespread they have been used extensively in studies of ecology{{Cite news|url=https://newzealandecology.org/nzje/2995|title=Exploring the concept of niche convergence in a land without rodents: the case of weta as small mammals|last=Griffin|first=M.|date=2011|work=New Zealand Journal of Ecology|access-date=2018-06-29|language=en}} and evolution.{{Cite journal|last=Bulgarella|first=Mariana|last2=Trewick|first2=Steven A.|last3=Minards|first3=Niki A.|last4=Jacobson|first4=Melissa J.|last5=Morgan-Richards|first5=Mary|date=2013|title=Shifting ranges of two tree weta species (Hemideina spp.): competitive exclusion and changing climate|journal=Journal of Biogeography|language=en|volume=41|issue=3|pages=524–535|doi=10.1111/jbi.12224|issn=0305-0270}}
Habitat
Tree wētā are commonly encountered in forests and suburban gardens throughout most of New Zealand. 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.{{Cite journal|last=Wehi|first=Priscilla M.|author-link1=Priscilla Wehi|last2=Jorgensen|first2=Murray|last3=Morgan-Richards|first3=Mary|date=2013|title=Sex- and season-dependent behaviour in a flightless insect, the Auckland tree weta (Hemideina thoracica)|url=https://newzealandecology.org/nzje/3076|journal=New Zealand Journal of Ecology|volume=37|issue=1|pages=75–83}}
Behaviour
Tree wētā are nocturnal and arboreal, hiding in hollow tree branches during the day and feeding at night.{{Cite web|url=https://www.visitzealandia.com/About/The-Wildlife/Reptiles-Frogs-Invertebrates/Tree-Weta|title=Tree wētā|website=www.visitzealandia.com|access-date=2019-01-27}} Their diet consists of leaves, flowers, fruit and small insects.{{Cite journal|last=Wehi|first=Priscilla M.|author-link1=Priscilla Wehi|last2=Hicks|first2=Brendan J.|date=2010|title=Isotopic fractionation in a large herbivorous insect, the Auckland tree weta|journal=Journal of Insect Physiology|volume=56|issue=12|pages=1877–1882|doi=10.1016/j.jinsphys.2010.08.005|pmid=20709068|issn=0022-1910}}{{Cite journal|last=Griffin|first=Melissa J.|last2=Morgan-Richards|first2=Mary|last3=Trewick|first3=Steve A.|date=2011|title=Is the tree weta Hemideina crassidens an obligate herbivore?|url=http://www.science.canterbury.ac.nz/nzns/issues/vol36-2011/griffin.pdf|journal=New Zealand Natural Sciences|volume=36|pages=11–19}} Males have larger heads and stronger jaws than females, though both sexes will stridulate and bite when threatened.{{Cite book|title=The biology of wetas, king crickets and their allies|last=Field|first=Laurence H.|publisher=CABI Pub|year=2001|isbn=9780851994086|location=Wallingford, Oxon., UK|oclc=559432458}}
File:Hemideina_crassidens_harem.jpg)]]
File:MA I066498 TePapa Hemideina-broughi-Buller1896 full.jpg
Species
The seven species of tree wētā are:
; Auckland tree wētā, Hemideina thoracica (White, 1846)[http://orthoptera.speciesfile.org/Common/basic/Taxa.aspx?TaxonNameID=1132065 Hemideina thoracica at OSF]
: Also known as tokoriro;{{Cite web|url=https://www.sciencelearn.org.nz/resources/1962-weta|title=Wētā|website=Science Learning Hub|language=en|access-date=2019-07-04}}{{Cite web|url=http://www.terrain.net.nz/friends-of-te-henui-group/local-insects/tree-weta.html|title=T.E.R:R.A.I.N – Taranaki Educational Resource: Research, Analysis and Information Network – Weta (Tree) Auckland (Hemideina thoracica)|website=www.terrain.net.nz|access-date=2019-07-04}} found throughout the North Island apart from the Wellington-Wairarapa region. Within this range are nine chromosome races{{Cite journal|last=Morgan-Richards|first=Mary|date=1997|title=Intraspecific karyotype variation is not concordant with allozyme variation in the Auckland tree weta of New Zealand, Hemideina thoracica (Orthoptera: Stenopelmatidae)|journal=Biological Journal of the Linnean Society|language=en|volume=60|issue=4|pages=423–442|doi=10.1111/j.1095-8312.1997.tb01505.x|issn=0024-4066|doi-access=free}}{{Cite journal|last=Morgan-Richards|first=Mary|last2=Wallis|first2=Graham P.|date=2003|title=A comparison of five hybrid zones of the weta Hemideina thoracica (Orthoptera: Anostostomatidae): Degree of cytogenetic differentiation fails to predict zone width|journal=Evolution|volume=57|issue=4|pages=849|doi=10.1554/0014-3820(2003)057[0849:acofhz]2.0.co;2|pmid=12778554|issn=0014-3820}} and there are five hybrid zones where six of these races meet.
; Hawke's Bay tree wētā, Hemideina trewicki Morgan-Richards, 1995{{Cite journal|last=Morgan-Richards|first=Mary|date=1995|title=A new species of tree weta from the North Island of New Zealand (Hemideina Stenopelmatidae: Orthoptera)|journal=New Zealand Entomologist|volume=18|issue=1|pages=15–23|doi=10.1080/00779962.1995.9721996|issn=0077-9962}}
: Hawke's Bay.
; Wellington tree wētā, Hemideina crassidens (Blanchard, 1851)
: Wellington, the Wairarapa, the northern part of the South Island, and the West Coast. They have been the subject of studies of coevolution,{{Cite journal|last=Duthie|first=C|date=2006|title=Seed dispersal by weta|journal=Science|volume=311|issue=5767|pages=1575|doi=10.1126/science.1123544|pmid=16543452}}{{Cite journal|last=Wyman|first=Tarryn E.|last2=Trewick|first2=Steve A.|last3=Morgan-Richards|first3=Mary|last4=Noble|first4=Alasdair D. L.|date=2010|title=Mutualism or opportunism? Tree fuchsia (Fuchsia excorticata) and tree weta (Hemideina) interactions|journal=Austral Ecology|language=en|volume=36|issue=3|pages=261–268|doi=10.1111/j.1442-9993.2010.02146.x|issn=1442-9985}} sexual selection,{{Cite journal|last=Kelly|first=Clint D.|date=2006|title=The Relationship Between Resource Control, Association with Females and Male Weapon Size in a Male Dominance Insect|journal=Ethology|language=en|volume=112|issue=4|pages=362–369|doi=10.1111/j.1439-0310.2006.01193.x|issn=0179-1613}} hybridisation{{Cite journal|last=Mckean|first=Natasha E.|last2=Trewick|first2=Steven A.|last3=Morgan-Richards|first3=Mary|date=2016|title=Little or no gene flow despite F1 hybrids at two interspecific contact zones|journal=Ecology and Evolution|language=en|volume=6|issue=8|pages=2390–2404|doi=10.1002/ece3.1942|issn=2045-7758|pmc=4783458|pmid=27066230}} and range shifts.
; Canterbury tree wētā, Hemideina femorata Hutton, 1898
: Marlborough and Canterbury.
; Mountain stone wētā, Hemideina maori (Pictet & Saussure, 1891)
: The drier areas of the central South Island high country, living above the treeline. This species abandoned life in the forest millions of years ago in favour of crevices and cavities under rocks.{{Cite book|title=NZ Wild Life : introducing the weird and wonderful character of natural New Zealand|last=Trewick|first=Steve|last2=Morgan-Richards|first2=Mary|publisher=Penguin|year=2014|isbn=9780143568896|location=Auckland, New Zealand|oclc=881301862}}
; Banks Peninsula tree wētā, Hemideina ricta Hutton, 1898
: A rare species only found on Banks Peninsula.
;West Coast bush wētā, Hemideina broughi (Buller, 1896)
: Overlaps with the Wellington tree wētā in Nelson and the northern West Coast.
The three North Island tree wētā species are closely related{{Cite journal|last=Buckley|first=Thomas R.|last2=Newcomb|first2=Richard D.|last3=Twort|first3=Victoria G.|date=2019-04-01|title=New Zealand Tree and Giant Wētā (Orthoptera) Transcriptomics Reveal Divergent Selection Patterns in Metabolic Loci|journal=Genome Biology and Evolution|language=en|volume=11|issue=4|pages=1293–1306|doi=10.1093/gbe/evz070|pmid=30957857|pmc=6486805}} but each has a distinctive set of chromosomes (karyotype).{{Cite journal|last=Mckean|first=NE|last2=Trewick|first2=SA|last3=Morgan-Richards|first3=M|date=2015|title=Comparative cytogenetics of North Island tree wētā in sympatry|journal=New Zealand Journal of Zoology|language=en|volume=42|issue=2|pages=73–84|doi=10.1080/03014223.2015.1032984|issn=0301-4223}} 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.