Notoreas isoleuca

This species was first described in 1897 by Edward Meyrick using material collected in Castle Hill by George Hudson.^[1][2] Meyrick temporarily suppressed this taxon in 1905 having come to the conclusion that it was a form of N. mechanitis but after a close study of the group Meyrick reinstated it in 1911.^[3] Hudson also discussed and illustrated this species in his 1928 book The Butterflies and Moths of New Zealand.^[4]

The genus Notoreas was reviewed in 1986 by R. C. Craw and the placement of this species within it was confirmed.^[5] However some experts regard this species as being of dubious taxonomic status and in need of further taxonomic investigation.^[6] The holotype specimen is held at the Natural History Museum, London.^[7]

Meyrick described the species as follows:

♀︎. 20 mm. Head and thorax ochreous-yellow, mixed with black. Forewings with termen bowed, rather oblique; dark fuscous, irregularly sprinkled with yellow; a cloudy transverse streak of yellow irroration near base, and another of yellow and white scales near beyond it, bent near costa; a curved white streak at 1⁄3, suffused with yellow on costa and in middle; a rather irregular tolerably straight white streak in middle, suffused with yellow towards costa, middle, and dorsum; a white streak at 2⁄3, obtusely angulated in middle, yellow on costa; subterminal line very fine, yellow, irregular, forming small spots on costa and in middle: cilia white, basal half fuscous. Hindwings as in forewings, but first three streaks obsolete, other two nearer base, post-median curved, hardly angulated.^[1]

This species is endemic to New Zealand.^[2] N. isoleuca has been found around Arthur's Pass and Ben Lomond as well as Mount Peel.^[4][3]

This species normally produces two broods per year but it has been hypothesised that at some localities it may produce only once in a season.^[8] The female moth lays her eggs within the flower buds of their host plant.^[9] When the larvae emerge from their eggs, they eat into the leaves or buds of their host, hiding from predators.^[9] Once they are large enough, they emerge to feed from the fresh growth of the plant.^[9] N. elegans pupate in a loose cocoon on the ground under their host.^[9] The species spends approximately 43 days in their cocoon before emerging as an adult.^[8] N. isoleuca are day-flying moths.^[9] They are low but fast flyers and constantly vibrate their wings to enable them to take off rapidly.^[9]

The host plants for the larvae of Notoreas isoleuca are endemic species within the genus Kelleria.^[10]

This day-flying species is on the wing from January to March.^[11]