Paradetis

This species was first described by Meyrick in 1883 under the name Parysatis porphyrias.[3][4] Meyrick went on to give a more detailed description of the species in 1884.[5] In 1886 Meyrick renamed the genus of this species Paradetis.[6]

George Hudson illustrated and discussed this species under its current name Paradetis porphyrias in both of his books New Zealand Moths and Butterflies (Macro-lepidoptera) in 1898 and The Butterflies and Moths of New Zealand in 1928.[7][8]

The larva of this species is thin and green and when mature is 20 mm long.[9]

Meyrick described the adult female of the species as follows:

Female. — 20 mm. Forewings moderate, costa sinuate in middle, apex almost acute, hindmargin deeply excavated on upper half and more shortly on lower third, so as to project bluntly below middle; yellow-ochreous, irregularly mixed with brown and purplish; veins clearly marked with fuscous; two slender ochreous-brown transverse lines, dilated on costa, first before middle, bent inwards near costa, second beyond middle, almost straight; beyond second a broad purplish shade, except near costa, dilated beneath to reach hindmargin; hindmargin purple: cilia white on excavations. Hindwings moderate, hindmargin shortly sinuate near inner angle; pale ochreous mixed with fuscous and purplish; a fuscous transverse fine before middle; a very broad purplish hindmarginal band.[5]

P. porphyrias is endemic to New Zealand.[10] Meyrick first collected the species near Otira Gorge at Arthur's Pass in January.[5] The species has also been found at Mount Arthur, Castle Hill, and Lake Wakatipu.[8]

Hypolepis millefolium

Alfred Philpott mentioned that the species frequented the banks of mountain streams.[11] P. porphyrias larvae likely feed on Hypolepis millefolium.[12][9]