In the small islands of New Zealand,
Giant weta is endemic to New Zealand and is an example of island gigantism: which is a biological phenomenon leading to a larger size than their mainland relatives because of their isolation and lack of large predators. A female giant weta filled with eggs can reach up to 70 grams or more!
There are eleven species of giant wētā, most of which are larger than other wētā, despite the latter already being large by insect standards.
The largest species is the Little Barrier Island giant weta. Large species can be up to 10 centimeters (4 in) not inclusive of legs and antennae, with body mass usually no more than 35 grams. But rarely, a female filled with eggs can reach up to 70 grams or more: one captive female reached a mass of about 70 grams (2.5 oz.), making it one of the heaviest documented insects in the world and even heavier than a sparrow.
The largest species of giant weta is the Little Barrier Island giant weta, also known as the wētāpunga, which means the “god of ugly things” in the Maori language. One example reported in 2011 weighed 71 grams, and a 72 grams specimen has been recorded.
Most populations of this amazing insect have been in decline since humans began modifying the New Zealand environment. All but one giant weta species are protected by law because they are considered at risk of extinction. When humans arrived in New Zealand hundreds of years ago, they inadvertently brought weta predators along with them, like rats and cats, which ate the insects.
To help safeguard this threatened species, an experimental breeding project was successfully undertaken by the staff at Butterfly Creek in South Auckland under the guidance of the Weta Recovery Group. Auckland Zoo was extremely successful at breeding hundreds of wētāpunga.
Little Barrier Island (Hauturu in Māori language, means “the resting place of the wind”), lies off the northeastern coast of New Zealand’s North Island. Located 80 kilometers (50 miles) to the north of Auckland, the island is separated from the mainland to the west by Jellicoe Channel, and from the larger Great Barrier Island to the east by Cradock Channel.
The island is an extinct andesitic volcanic cone, roughly circular in shape, about 6 kilometers (3.7 miles) across, with an area of 28 km2 (10.8 square miles).
Approximately 40 species of rare or endangered birds, 14 reptile and 2 bat species, and more than 400 native plants live in the Little Barrier Island, according to the New Zealand Department of Conservation (DOC).
Visitors need a permit from the DOC before visiting the island.
The giant weta is usually less social and more passive than other weta species. Their genus name, Deinacrida, is Greek for “fierce grasshopper”. Its diet consists of plants (even carrot!), other small insects and fruit.
Another amazing fact about the wētāpunga: many species are alpine specialists (live in high altitudes). Five species are only found at high elevation in South Island. The scree weta (D. connectens) lives about ~1200 meters (3,920 feet) above the sea level and freezes solid when temperatures drop below -5°C (23°F).
- Giant weta on Wikipedia
- “10 Intense Facts About the Giant Weta” on Mental Floss
- Wētāpunga on New Zealand Government Department of Conversation webpage
- “Te Hauturu-o-Toi / Little Barrier Island Nature Reserve” on the New Zealand Department of Conservation official website