Tree wētā are wētā in the genus Hemideina of the familyAnostostomatidae. The genus is endemic to New Zealand.[2] There are seven species within the genus Hemideina, found throughout the country except lowland Otago and Southland.[3] Because many tree wētā species are common and widespread they have been used extensively in studies of ecology[4] and evolution.[5]
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.[6]
Tree wētā are nocturnal and arboreal, hiding in hollow tree branches during the day and feeding at night.[7] Their diet consists of leaves, flowers, fruit and small insects.[8][9] Males have larger heads and stronger jaws than females, though both sexes will stridulate and bite when threatened.[10]
Also known as tokoriro;[12][13] found throughout the North Island apart from the Wellington-Wairarapa region.[2][5] Within this range are nine chromosome races[14][15] and there are five hybrid zones where six of these races meet.[15]
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.[21]
Overlaps with the Wellington tree wētā in Nelson and the northern West Coast.
The three North Island tree wētā species are closely related[22] but each has a distinctive set of chromosomes (karyotype).[23] 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.[20]
^ abcBulgarella, Mariana; Trewick, Steven A.; Minards, Niki A.; Jacobson, Melissa J.; Morgan-Richards, Mary (2013). "Shifting ranges of two tree weta species (Hemideina spp.): competitive exclusion and changing climate". Journal of Biogeography. 41 (3): 524–535. doi:10.1111/jbi.12224. ISSN0305-0270.
^ abMorgan-Richards, Mary; Wallis, Graham P. (2003). "A comparison of five hybrid zones of the weta Hemideina thoracica (Orthoptera: Anostostomatidae): Degree of cytogenetic differentiation fails to predict zone width". Evolution. 57 (4): 849. doi:10.1554/0014-3820(2003)057[0849:acofhz]2.0.co;2. ISSN0014-3820. PMID12778554.
^Morgan-Richards, Mary (1995). "A new species of tree weta from the North Island of New Zealand (Hemideina Stenopelmatidae: Orthoptera)". New Zealand Entomologist. 18 (1): 15–23. doi:10.1080/00779962.1995.9721996. ISSN0077-9962.
^Wyman, Tarryn E.; Trewick, Steve A.; Morgan-Richards, Mary; Noble, Alasdair D. L. (2010). "Mutualism or opportunism? Tree fuchsia (Fuchsia excorticata) and tree weta (Hemideina) interactions". Austral Ecology. 36 (3): 261–268. doi:10.1111/j.1442-9993.2010.02146.x. ISSN1442-9985.
^Kelly, Clint D. (2006). "The Relationship Between Resource Control, Association with Females and Male Weapon Size in a Male Dominance Insect". Ethology. 112 (4): 362–369. doi:10.1111/j.1439-0310.2006.01193.x. ISSN0179-1613.
^Trewick, Steve; Morgan-Richards, Mary (2014). NZ Wild Life : introducing the weird and wonderful character of natural New Zealand. Auckland, New Zealand: Penguin. ISBN9780143568896. OCLC881301862.
^Mckean, NE; Trewick, SA; Morgan-Richards, M (2015). "Comparative cytogenetics of North Island tree wētā in sympatry". New Zealand Journal of Zoology. 42 (2): 73–84. doi:10.1080/03014223.2015.1032984. ISSN0301-4223.