T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Stick insect (Gaint) Argosarchus horridus

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Phasmatodea
Suborder: Verophasmatodea
Family: Phasmatidae
Subfamily: Phasmatinae
Genus: Argosarchus
Species: A. horridus
Binomial name: Argosarchus horridus
Synonym: Argosarchus spiniger
Common name: New Zealand giant stick insect, Bristly stick insect

Argosarchus horridusis a stick insect of the family Phasmatidae. The name 'phasmatid' means phantom, a reference to the way this family of insects disappear into their surroundings. Argosarchus horridusis is endemic to New Zealand and the only member of its genus. They are found throughout much of the North Island and large areas of the South  Island. 
Females can have a body length up to 20 cm and it is the longest New Zealand insect. This species ranges in colour from a pale white to a dark brown. The male is much smaller.

Clitarchus and Argosarchus species of stick insects can reproduce with or without males. Reproduces without males is called parthenogenesis (virgin birth). A female will only mate with a male when it suits her and they have found ways to repel males so they can have young without any male interference. They emit an anti-aphrodisiac chemical that repels the male. If a male is still keen, the female will curl her abdomen and kick her legs to repel him. Males win these sexual conflicts more frequently than the females hence parthenogenesis remains rare though some populations consist of females only. Females drop their eggs to the ground and in spring when it's warmer they hatched. The nymphs which look similar to adults make their way and climb the nearest food plant. Due to having an exoskeleton, the growing nymphs have to moult. Moulting occurs at night and occurs up to six times till adulthood.

They feed on a wide range of plants including Lophomyrtus bullata (ramarama), Plagianthus regius (Ribbonwood), Lophomyrtus bullata (Ramarama), Muehlenbeckia australis (Pohuehue), Hoheria populnea (Lacebark), Metrosideros (Climbing ratas) and the Rubus species (Blackberry, Bush lawyer). 

Argosarchus horridusis’s main predator are birds who hunt by sight and as a result during the day Argosarchus horridusis usually sits where they are least visible, remaining still or moving very slowly, or swaying like leaves in the wind. They often settle where there are a fewest of leaves but lots of twigs in the trees it feeds on. They are also predated on by introduced wasps, rats, mice, possums and the mustelids (weasels, stoats, ferrets), all which devour insects.

A New Zealand giant stick insect photographed at Percy Reserve, Upper Hutt, Wellington


 

Argosarchus horridus feeding. The effects of insect nibbling can be seen on the leaves margins.


Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/