Tree wētā


Tree wētā are insects in the genus Hemideina of the family Anostostomatidae. The genus is endemic to New Zealand. There are seven species within the wētā genus Hemideina, found throughout the country except lowland Otago and Southland. Because many pūtangatanga species are common and widespread they have been used extensively in studies of ecology and evolution.

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 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.

Behaviour

Tree wētā are nocturnal and arboreal, hiding in hollow tree branches during the day and feeding at night. Their diet consists of leaves, flowers, fruit and small insects. Males have larger heads and stronger jaws than females, though both sexes will stridulate and bite when threatened.

Species

The seven species of tree wētā are:
; Auckland tree wētā, Hemideina thoracica
; Hawke's Bay tree wētā, Hemideina trewicki Morgan-Richards, 1995
; Wellington tree wētā, Hemideina crassidens
; Canterbury tree wētā, Hemideina femorata Hutton, 1898
; Mountain stone wētā, Hemideina maori
; Banks Peninsula tree wētā, Hemideina ricta Hutton, 1898
;West Coast bush wētā, Hemideina broughi
The three North Island tree wētā species are closely related but each has a distinctive set of chromosomes. 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.