(Deinacrida spp., Pachyrhamma spp., Hemideina spp., etc.).
These wingless orthopteran insects are well represented in New Zealand and are found in the forest and in caves. The commonest weta is found throughout the country in rotten logs, in old tree trunks, and under bark. It has a body length of about 5 cm and has much longer antennae. The male is characterised by its large black head. The general colouration of the insect is dark brown. It is capable of making a peculiar scraping sound by rubbing its hind legs against ridges on the side of its body. Although it appears to be a fearsome creature, it is harmless but can give a nip with its mandibles if incautiously handled.
Giant wetas are now rare and appear to be restricted to several off-shore islands. They are heavy insects with a body of up to 10 cm in length and with powerful spined hind legs. They are nocturnal and feed on foliage of trees and on grass. Wetas can run very quickly and jump great distances. They are seldom seen in daylight but feed at night, mainly on plants.
Cave wetas are found a short distance inside caves and tunnels. They are small wetas with a body length of up to 30 mm, but they are characterised by their extremely long legs and antennae. The length from tip of antennae to the end of hind leg can be up to 40 cm and the antennae may consist of over 500 segments. Cave wetas lay eggs, up to 20 at a time, in soft mud along the walls of the caves. The life cycle is about two years.
In New Zealand the Maori name “weta” is popularly applied to insects of the Order Orthoptera, which belong to two families, the Henicidae of Karny 1937, and the Rhaphidophoridae of Kirby 1883. The former includes the tree or ground wetas and the “taipos” of the West Coast of the South Island, the name of which to the Maori means “the devil who comes by night”. The latter includes the insects generally known as “cave wetas”.
by Roy Alexander Harrison, D.SC., Senior Lecturer in Agricultural Zoology, Lincoln Agricultural College.