The New Zealand mole cricket (''Triamescaptor aotea'') is a wingless member of the mole cricket family Gryllotalpidae.

Endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to New Zealand, it lives underground and is rarely seen. It is now restricted to parts of the southern

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

Taxonomy

The mole cricket was well known to

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...

, who encountered it when cultivating garden plots and called it honi. Mole crickets collected in New Zealand were assumed to be the European species ''Gryllotalpa vulgaris'' (a synonym of '' Gryllotalpa gryllotalpa''), which has a wingless nymph that resembles the adult New Zealand species. ''Triamescaptor aotea'' was named and described by Norman Tindale in 1928 from two specimens collected in 1915 at Aramoho,

Whanganui Whanganui (; ), also spelled Wanganui, is a city in the Manawatū-Whanganui region of New Zealand. The city is located on the west coast of the North Island at the mouth of the Whanganui River, New Zealand's longest navigable waterway. Whangan ...

. It is the only species in its genus, and the only genus in tribe Triamescaptorini. Its closest relatives are two Australian species of ''Gryllotalpa''. ''Triamescaptor'' is sometimes incorrectly spelled "''Trimescaptor"'' in later publications.

Description

''Triamescaptor aotea'' is long, and medium to dark brown in colour, with distinct protruding antennae and long rear processes (or cerci). Its rear cerci are sensory, and in its tunnel it is able to move backwards as easily as forwards. The first segment of its thorax is extended, rounded, and armoured. Its front legs are heavily modified for digging, flattened and shovel-like, with just three claw-like processes or dactyls on its

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

(''Gryllotalpa'' has four), two movable and one fixed. The New Zealand mole cricket, unlike other species of Gryllotalpidae, has no wings, not even vestiges. Because mole crickets produce sound by stridulation of their wings, this species is necessarily silent and lacks the ears other species have on their front tibia. Any winged mole crickets found in New Zealand are likely to be introduced European ''

Gryllotalpa ''Gryllotalpa'' is a genus of insects in the mole cricket family Gryllotalpidae. Species The ''Orthoptera Species File'' lists a number species, including cryptic species groups (indicated with a * and often distinguished only by song patterns) ...

'', with which the New Zealand species has sometimes been confused.

Ecology

New Zealand mole crickets live underground, in circular galleries roughly in diameter and below the surface. Females lay clutches of eggs in side chambers off the gallery and guard them until they hatch. They are omnivorous, feeding on the roots of plants and other burrowing insects such as grass grubs (''

Costelytra zealandica ''Costelytra zealandica'' (commonly known as the grass grub) is a species of scarab beetle found in forested areas of greater Wellington Greater Wellington, also known as the Wellington Region (Māori: ''Te Upoko o te Ika''), is a non-unita ...

'') and porina moth caterpillars ('' Wiseana''). During rain or flooding mole crickets emerge from their burrows to feed; they have been recovered from the stomachs of eels at Lake Pounui in the Wairarapa, which forage in flooded paddocks at night.

Distribution

Because it lives underground this species is vulnerable to agricultural cultivation. Formerly widespread, it now seems to be localised to parts of the lower North Island, including Hawke's Bay,

, near Levin,

Lake Wairarapa Lake Wairarapa is a lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, a ...

and Lake Pounui, and on

D'Urville Island D'Urville Island (), Māori language, Māori name ' ('red heavens look to the south'), is an island in the Marlborough Sounds along the northern coast of the South Island of New Zealand. It was named after the France, French List of explorers, ...

. It is probably also eaten by introduced rats. The

Department of Conservation An environmental ministry is a national or subnational government agency politically responsible for the environment and/or natural resources. Various other names are commonly used to identify such agencies, such as Ministry of the Environment ...

considers the species at risk because it is naturally uncommon.

References

External links

* New Zealand mole cricket discussed in RNZ ''Critter of the Week''
19 May 2017
{{Taxonbar, from1=Q10702234, from2=Q14503748 Gryllotalpidae Endemic fauna of New Zealand Insects described in 1928 Mole cricket Endemic insects of New Zealand