Percnodaimon | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Lepidoptera |
Family: | Nymphalidae |
Genus: | Percnodaimon Butler, 1876 |
Species: | P. merula |
Binomial name | |
Percnodaimon merula (Hewitson, 1875) | |
Synonyms | |
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Percnodaimon merula, the black mountain ringlet, is a satyrid butterfly in the family Nymphalidae. It is currently the only recognised species in the monotypic genus Percnodaimon, endemic to New Zealand, although there may be other undescribed species in the genus. The black mountain ringlet is notable for living exclusively in rocky areas of New Zealand's Southern Alps, usually above 1200 m. Its eggs are laid on rocks, its larvae feed on mountain Poa species, and it pupates under a stone. It has distinctive dark velvety wings and a zig-zag flight pattern over the scree slopes on which it lives.
This species has had a complicated taxonomic history. It was originally described as Erebia pluto by Richard W. Fereday in 1872 from the Craigieburn Range in the South Island, [1] and was moved to the new genus Percnodaimon by Butler in 1876. [2] It was known as Percnodaimon pluto for many years, and Wise in 1967 regarded this as the correct name for the species, [3] but was eventually synonymised with P. merula, under which name it is usually referred to today.
Most sources consider Percnodaimon monotypic, but in 2012 mitochondrial gene sequencing by Hamish Patrick for his Lincoln University Hons thesis suggested it was a species complex, with up to six species in the genus. [4] In their 2012 guide to South Pacific butterflies, Brian and Hamish Patrick stated there are up to eight species of Percnodaimon still to be described, based on wing shape, pattern, and colour, size, behaviour, and season of emergence. Their species list was as follows: [5]
Although the Patricks stated in 2012 that nuclear DNA was being studied with a view to formally naming and describing these species, [5] as of 2022 that had yet to happen, and P. merula is still considered the only species in the genus.
Its Māori name, pepe pouri, means "dark moth", and is applied to several ringlet species, including the forest ringlet ( Dodonidia helmsii ) and Butler's ringlet ( Erebiola butleri ).[ citation needed ]
The wingspan of the Percnodaimon imago can be between 35 and 55 mm, and its broad velvety wings are usually black or brown across the dorsal surface, sometimes with a purple reflection. Forewings have characteristic black and white circles inside a patch of brown at their distal ends. There is little sexual dimorphism: males and females are similar in appearance, with females a little larger. The row of large pale spots often found on the underside of the hindwings is more noticeable in females. [5]
Black mountain ringlets fly slowly in zigzag patterns, especially on a sunny day, taking advantage of thermals and often gliding in a "V" position.
"When disturbed this insect flies often with considerable rapidity and thus often eludes the net, so that the capture of a good series of specimens on a rugged mountain-slope is usually very exciting, if not actually dangerous work." —George V. Hudson (1928) [6]
Wing colour plays an important physiological role: the dark wings with a large surface area absorb sunlight and store heat, essentially acting like solar panels, an adaptation to the cool climate of the Southern Alps. The butterfly sits with its wings open and turned towards the sun, flying while the sun is shining and hiding amongst rocks when clouds intervene. [7] At night they shelter deep in rocky crevices. [5]
The genus Percnodaimon is restricted to the dry eastern mountains in the South Island of New Zealand, on greywacke scree slopes and amongst rockfalls. [7] It occurs at altitudes ranging from 800 to 2500 metres, up to 3100 m in the northern mountains of the South Island. Although the butterfly is less common below 1200 m, it can be found down to 800 m on valley floors and passes if the scree habitat is present. It can be quite common and even seasonally abundant in suitable habitat. [5]
The adult female black mountain ringlet deposits her eggs atop stones on alpine slopes, rather than on a larval food plant. When the sun is out it heats the stone's exposed surface, incubating the eggs. [7] This behaviour is unique among New Zealand butterflies and is only seen in a handful of butterfly species occupying the Himalayas and European Alps.[ citation needed ]
The eggs are initially blue, eventually turning speckled and brown, which allows them to blend in with the stony background. About two days before hatching this colouration is lost and the brown head of the larvae becomes visible. The hatching process takes around 12 days, or longer if the eggs are at higher altitudes. To sustain itself the newly-hatched larva consumes its egg casings, which have sufficient nutrients for early larval stages.[ citation needed ]
Percnodaimon larvae vary from dull grey to brown and have black anterior setae. The larvae have five instars, each of which take about a month in pleasant summer temperatures, but up to eight months over winter. For this reason the butterfly can stay in its larval stage for up to two years, and can be found almost year-round in an instar stage.
The alpine grasses Poa colensoi , P. buchananii , and other Poa species are the larval food plant. These tussocks are common throughout the Southern Alps, but larvae are present only where the grass grows adjacent to rocky areas. [8] Black mountain ringlet larvae are night feeders to avoid predators, which can easily spot them feeding on the tips of tussock blades. They spend little time feeding, but instead conceal themselves in nearby hiding spots. [7]
At the start of pupation the black mountain ringlet turns grey with brown speckles to match the surrounding stones. Unlike most butterflies pupae are suspended horizontally rather than vertically, and are attached to the undersurface of a rock with a large cremaster, a hook-shaped protuberance on the abdomen. Pupae have been found up to 3 feet away from the nearest food plant. The adult butterflies emerge 2 to 3 weeks later.
Adult black mountain ringlets are found in summer, from December to February, and the Patricks note that early versus late emergence is one of the characteristics distinguishing the undescribed species. [5] This species is considered to live about a year in its adult stage, but as the larvae can take two or three summers to grow to full size there is a possibility that it can live up to four. This slow growth may reflect the extreme climate and conditions of New Zealand's Southern Alps. [8]
The small mountain ringlet or mountain ringlet is a butterfly of the family Nymphalidae. It is found in mountainous regions of southern and central Europe.
The Scotch argus is a butterfly of the family Nymphalidae. In spite of its English name argus, it is not a close relation of the brown argus nor the northern brown argus.
The forest ringlet, also known as Helms' butterfly, or te pēpepe pōuri or pepe pouri in the Māori language, is a rare butterfly of the family Nymphalidae endemic to New Zealand. It is the only species in the genus Dodonidia.
Erebiola butleri, or Butler's ringlet, is an elusive New Zealand endemic butterfly, discovered in 1879 by John Enys at the alpine pass at the head of the Rakaia River. It is the only member of the genus Erebiola.
Erebia is a Holarctic genus of brush-footed butterflies, family Nymphalidae. Most of the about 90–100 species are dark brown or black in color, with reddish-brown to orange or more rarely yellowish wing blotches or bands. These usually bear black spots within, which sometimes have white center spots.
Erebia euryale, the large ringlet, is a species of butterfly belonging to the family Nymphalidae.
Erebia alberganus, the almond ringlet or almond-eyed ringlet, is a butterfly of the family Nymphalidae.
Erebia tyndarus, the Swiss brassy ringlet, is a European brush-footed butterfly species of the subfamily Satyrinae.
The bright eyed ringlet is a member of the Satyridae subfamily of Nymphalidae. It is a high mountain butterfly found in the Pyrenees, Massif Central, Alps and Balkan mountains. It has recently been confirmed to occur in the southern chain of the Carpathians.
The yellow-banded ringlet is a member of the subfamily Satyrinae of the family Nymphalidae. It is a high mountain butterfly found in a small area of the Alps in Switzerland and Italy.
The marbled ringlet is a member of the subfamily Satyrinae of the family Nymphalidae.
The Styrian ringlet is a member of the subfamily Satyrinae of the family Nymphalidae. It is a mountain butterfly found in the Austrian and Italian Alps, Croatia and Slovenia.
The water ringlet is a member of the subfamily Satyrinae of family Nymphalidae. It is a high altitude butterfly found in the Alps, Bavaria, Styria, Pyrenees, Carpathians and Bulgaria.
Erebia cassioides, the common brassy ringlet, is a member of the subfamily Satyrinae of family Nymphalidae.
The false Mnestra ringlet, Erebia aethiopellus, is a butterfly of the family Nymphalidae found in France and Italy (Alps).
The Stygian ringlet is a butterfly belonging to the subfamily Satyrinae, the "browns", within the family Nymphalidae. It is found locally in the Alps on dry limestone slopes. It is very similar to the Styrian ringlet and has sometimes been included in that species.
Erebia polaris, the Arctic woodland ringlet, is a butterfly of the family Nymphalidae. It is found in Lapland and boreal Asia.
Argyrophenga antipodum, the common tussock or tussock ringlet, is a species of butterfly commonly found in the South Island of New Zealand.
Ichneutica maya is a moth of the family Noctuidae. It is endemic to New Zealand. It is found in the mountains in southern half of the North Island and in the South Island. I. maya is a distinctively coloured and patterned moth and as such is unlikely to be confused with similar species. I. maya can be found in the southern half of the North Island down through the South Island. This species can be found in alpine to subalpine zones with high rainfall but in Southland this species can be found down to sea level. This life history in the wild is unknown, nor has its larval host species been confirmed. Adults are on the wing from December to March and are attracted to sugar and light traps.
Ichneutica blenheimensis is a species of moth in the family Noctuidae. It is endemic to New Zealand and is found throughout the North, South and the Stewart Islands. This species appears to prefer drier eastern localities and is rarely collected in western North Island forested areas. It does not appear to be frequently collected in inland dry tussock grassland habitats. The host plant for the larvae of this species is likely to be the golden sand sedge pīngao which is now absent from the moths type locality. However Chappell has raised very young larvae on grass species and the more developed larvae consumed Phormium tenax. Adults are on the wing from November to March and are attracted to both light and sugar traps. The blackish forewing fringes are diagnostic of this species. But worn specimens of I. arotis can be confused with worn specimens of I. blenheimensis. However I. arotis can be distinguished from I. blenheimensis as it has a scale-tuft on the thorax and dark longitudinal stripes on the tegula. This species is classified as "At Risk, Naturally Uncommon" by the Department of Conservation.