Mnesarchaea paracosma

This species was first described by Edward Meyrick in 1885.[2] The male lectotype specimen, collected by Meyrick at Lake Wakatipu on the 15 December 1882, is held at the Natural History Museum, London.[3]

M. paracosma illustrated by George Hudson

Lake Wakatipu, type locality of M. paracosma.

Meyrick described the species as follows:

Forewings yellowish-ochreous, with a wedge-shaped whitish streak from middle of costa, and some irregular dark fuscous suffusions.[2]

Hudson went on to give a more detailed description in his 1928 publication The butterflies and moths of New Zealand.[4] He described the species as follows:

The expansion of the wings is considerably under 3⁄8 in. The forewings are elliptical, pale ochreous-golden with two whitish transverse bands; the first at 1⁄2 strongly oblique almost reaching the tornus, the second at 3⁄4 nearly straight; there are a few faint brownish scales on the costa near the base and on the fold; a conspicuous patch of darker scales in the disc before the middle; several irregular elongate patches near the outer edge of the first transverse band and a very dense patch of brownish scales on the apical area; the cilia are golden-ochreous mixed with brownish scales near the apex. The hind-wings are grey with strong golden-purplish reflections; the cilia are brown-ochreous on the costa and grey on the termen.[4]

This species is small and coloured ochreous-brown, with brown, white and yellow patches over its forewings.[5] The antennae of M. paracosma are pale ochreous-yellow.[5] The male of this species has unusually shaped genitalia that assists with the identification of this species.[6]

This species is endemic to New Zealand and can be found in the Kaikōura, mid and south Canterbury, MacKenzie, Otago Lakes, Central Otago, Dunedin, Fiordland and Southland areas.[7][5]

M. paracosma lives in a wide variety of habitats including tussock grasslands, shrubland, and damp native beech or podocarp forests but are likely to be found near watercourses or moist areas as a result of their larvae existing on periphyton.[5] The species exists at a range of altitudes from around sea-level up to 1200 m.[5]

Adults of this species are on the wing from October to February.[5] Although this moth is normally day flying it is also attracted to light and has been collected via night light trapping.[5]

The larvae of M. paracosma require moist periphyton and are believed to feed on a variety of fungi, algae, mosses, liverworts and fern sporangia.[5]