Kingdom:   Animalia
Phylum:     Arthropoda
Class:        Insecta
Order:       Orthoptera
Suborder:   Ensifera
Family:      Anostostomatidae
Genus:      Hemideina
Species: H. crassidens
Binominal name: Hemideina crassidens
Common name: Wellington tree weta

Hemideina crassidensis an arboreal species of weta in the genus Hemideina and in the family Anostostomatidae. It is distributed in southern NorthIsland and northern parts of South Island, and the South Island West Coast. It is found on Mt Egmont /Taranaki.
They are usually up to 40 mm in length but a very large specimen can reach 70mm. They can weigh between 3 and 6g. They live in holes in live and dead trees that are formed by wood-boring insects or moth larvae and where rot has set in after a branch has broken off. They are capable of making their own hole. The hole (gallery) is maintained by the weta and any new developing bark surrounding the opening is chewed away.
Hemideina crassidensis forms harems consisting of one adult male and up to 10 adult female. The males if not in a harem will be a wanderer and can be found in many places other than in trees. They are nocturnal and all exit their holes and feed.  This species always returns to the same hole. Hemideina crassidens are omnivorous and feed on a wide range of foliage, bark, insects (crickets, caterpillars, moths, locust nymphs, cicadas, katydids, aphids, mealworms, and spiders) and fruit.
The females lay their eggs in the soil during April and May. The eggs are black; cigar-shaped and range in size between 5 and 6.5 mm long. They are laid vertically in the soil at various depths.

Wellington tree weta. Hemideina crassidens-001.JPG 

A female with a long ovipositor(egg laying tube) that looks like a stinger at the rear of her body.
Female WellingtoneTree weta.jpg

Wellington tree weta. Hemideina crassidens.JPG 

Male in an aggressive stance.
Wellington tree weta. Hemideina crassidens-002.JPG

A male weta.
The pair of antenna-like appendages at the rear of the weta abdomen are called cerci. They are sensory organs covered in hundreds of filiform mechanosensory hairs that are sensitive to low-amplitude air currents.Wellington tree weta. Hemideina crassidens-003.JPG

Wellington tree weta. Hemideina crassidens-007.JPG

The underside of a male Wellington weta.
Wellington tree weta. Hemideina crassidens-006.JPG

The hind leg.
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Thanks to Wikipedia for text and information: