Paradetis

Paradetis is a monotypic moth genus in the family Geometridae. Its only species, Paradetis porphyrias, also known as the orange and purple fern looper, is endemic to New Zealand. The genus and species were first described by Edward Meyrick, the genus in 1885 and the species in 1883.

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

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.

Description
The larva of this species is thin and green and when mature is 20 mm long.

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."

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

Habitat and host species
Alfred Philpott mentioned that the species frequented the banks of mountain streams. P. porphyrias larvae likely feed on Hypolepis millefolium.