Common tussock butterfly (Argyrophenga antipodum)
Species: A. antipodum
Binomial name: Argyrophenga antipodum
Common name: Common tussock, Tussock ringlet
Argyrophenga antipodum (Common tussock) is the commonest and the most widespread of the three endemic species in the genus Argyrophenga. It is found only in the eastern, southern and central regions of New Zealand’s South Island, and is most abundant in lowland Canterbury, Otago and Southland.
The Common tussock can be found in a variety of habitats ranging from sea-level salt marshes and grasslands, to an alpine zone as high as 2000 metres. This species can be abundant in native and introduced grasslands, both tall and short, as well as various open-country, semi-natural sceneries in New Zealand’s South Island.
Argyrophenga antipodum is approximately 12-17mm long with a wingspan of about 35-45mm. The fore and hind wings each have a very large orange patch. The orange patch on the forewing has one black patch that has in its centre two white dots. The hind wing has three black patches with a single white dot on the orange area.
Male and female common tussock butterflies are quite different in body shape, as females are shorter and have more rounded bodies compared to the males.
Common tussock butterflies have very distinct silver streaks on the underside of their wings. The sexes are coloured differently with the males being darker in colour and having more red and brown on them and the females are more of a yellow colour, but they both have very similar patterns or markings on their topside and underside.
The eggs are laid singly on feed plants such as Chionochloa rubra, Meadow Grass, Poa poiformis, Snow Tussock, and Wood Meadow-Grass grasses including Poa, Festuca. At the larval stage the caterpillars are able to camouflage themselves amongst various tall and short grasses. This ability to camouflage among the host plants continues when A. antipodum develop into pupae, or reach the chrysalis stage of development. There is one generation per year in lowland areas but it is suspected that larvae may pass 2 winters at high elevations. Adult butterflies fly from late October to late March.
Like the Janita's Tussock butterfly (Argyrophenga janitae) both male and female of the Common tussocks are known to have a slow, lazy flight pattern which is relatively close to the ground, thus allowing for frequent feeding on various flowers and plants. When settling they often land awkwardly among grasses and have trouble finding a footing. They will bask with wings fully outspread in calm sunny weather but keep them closed if it is overcast or breezy. If alarmed they flash open their wings momentarily to expose the diematic ocelli, and then instantly drop deep into the grass tussocks where the striped undersides of their hindwings afford them excellent camouflage among the stems and grass blades.