Stick insects are a group of plant feeding insects characterised by a remarkable similarity to their host vegetation. Stick insects belong to the insect order Phasmatodea and are found throughout the world, being most common and diverse in the tropics. There are about 3,500 described species throughout the world and many undescribed species. Stick insects are related to other insect orders such as Orthoptera (grasshoppers, weta, and crickets), Mantophasmatodea (gladiators), and Embioptera (web spinners). The higher level taxonomy of stick insects and their relationships to other insects is currently being researched.
Stick insects feed on vegetation and are usually active after dark. They can be found on a variety of native plants in addition to some introduced plants common in gardens. When disturbed, stick insects will often fall to the ground and “play dead” for hours. Another bizarre behaviour is the “dance”, where the stick insect sways back and forwards for hours in a peculiar motion, the function of which is a mystery. Many stick insect species, including some New Zealand species, can reproduce without males, a mode of reproduction known as parthenogenesis. Stick insects are relatively common in New Zealand although introduced wasps, rats and possums are a threat in some areas.
New Zealand has ten genera of stick insect and 23 recognised species. However, this number is likely to change as taxonomic research progresses, and scientists are already aware of undescribed species from various localities. Because of the great taxonomic problems that stick insects present identifying New Zealand stick insects cannot yet be done reliably in many cases. However, the information on this web site and the paper by Jewell and Brock (2002) will allow identification to genus.