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


Weta (Poor Knights Giant Weta ) Deinacrida fallai

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Orthoptera
Family: Anostostomatidae
Genus: Deinacrida
Species: D. fallai
Binomial name: Deinacrida fallai
Common name: Poor Knights Giant Weta, wetapunga

Deinacrida fallai is a species of insect in family Anostostomatidae. It is endemic to the Poor Knights Islands, off northern New Zealand. This sizeable species belongs to a subset known as giant weta (Deinacrida), which comprises some of the largest insects on Earth. Deinacrida fallai can have an overall length of 20 cm or 10 cm not inclusive of legs and antennae. One female was weighed at 49 grams.
They are usually found on Meterosideros excelsa (Pohutukawa), epiphytes, Xeronema callistemon (Poor Knights Lily, Rhopalostylis sapida (Nikau palm) and Cyathea dealbata (Ponga). Like other giant weta they are thought to be primarily vegetarian, and invertebrates only form a minor part of their diet. They stayed well-hidden during the day and emerged at night to feed.
Deinacrida fallai are arboreal but they do venture to the ground for oviposition. The female lays eggs with her ovipositor in soil under forest litter. The young hatch at night. The first instars are green and as they mature their colour changes to a dull yellow by the fourth instar stage. Adults are a pale brown with dark brown lower hind limbs, a line of black markings on its back and black stripes along the flanks.
Like all insects Deinacrida fallai have to moult their hard exoskeleton in order to grow. A moulting female usually hangs upside down upside down and emerges from the exoskeleton. Once emerged she then eats her old skin, recycling the chitin while her new skin hardens. Chitin is a long-chain polymer fibre that hardens and makes up 50% of the insects exoskeleton cuticle.