Metacrias huttoni


Metacrias huttoni, known as the Alpine tiger or Alpine tiger moth, is a species of moth in the family Erebidae. This species is endemic to New Zealand, where it is known from the eastern areas of the South Island. The female of the species is flightless and buff coloured whereas the male is brightly coloured and flies during the day.

Taxonomy

This species was described by Arthur Gardiner Butler in 1879 using two specimens collected in Queenstown by Frederick Hutton and named Phaos huttonii. In 1886 Edward Meyrick assigned this species to the genus Metacrias. George Hudson discussed and illustrated this species in his 1898 publication New Zealand moths and butterflies using the name Metacrias huttonii. He again discussed and illustrated this species in his 1928 book The Butterflies and Moths of New Zealand. In this publication Hudson used the name Metacrias huttoni to describe the species following George Hampson's use of that spelling in his Catalogue of Lepidoptera Phalaenae in the British Museum. This spelling has since been in common use as evidenced in the New Zealand Inventory of Biodiversity, New Zealand Arthropod Collection as well as the Museum of New Zealand Te Papa Tongarewa. The holotype specimen is held at the Natural History Museum, London.

Description

The larvae of this species are approximately long, black and very hairy. The hairs on the terminal segments are the longest and the shortest hairs are reddish-ochreous-brown. There is are blue dots around each segment except the second.
Adults males are brightly coloured and diurnal, while females are buff coloured and extremely short winged.
Butler described the species as follows:

Distribution

This species is endemic to New Zealand. It is known from the eastern areas of the South Island.

Biology and behaviour

The female of the species is semiapterious and remains within her cocoon for mating and egg laying. As a result of this, the population disbursal of the species is limited to the wanderings of the larvae. The male of the species is diurnal and is on the wing from December to March. Males are attracted to females by pheromones. Males of this species can be attracted to the scent of females of different species within their genus. Researchers have used females as lures to take advantage of this behaviour to detect males in new localities. The larvae hibernates during winter. Pupae cocoons are normally found beneath stones.

Habitat and host species

This species prefers montane to low-alpine habitats. The larvae of M. huttoni feed on various mountain grasses. These include introduced species such as Trifolium repens, Arenaria serpyllifolia, Rumex acetosella, Cerastium ''fontanum and Taraxacum officinale as well as endemic species such as Festuca novae-zelandiae and indigenous species from the genera Acaena, Muehlenbeckia, Wahlenbergia and Raoulia''.

Threats

It has been shown that sheep grazing within the habitat of this species is detrimental to its populations. M. huttoni is a host species for the parasitoid wasps Echthromorpha intricatoria and Cotesia urabae.