Helastia farinata

It was first described by William Warren in 1896 using specimens collected by George Hudson in Wellington and named Xanthorhoe farinata.[3][1] In 1912 Louis Beethoven Prout placed this species in the genus Larentia and affirmed this placement again in 1939.[4][5] Edward Meyrick returned this species to the genus Xanthorhoe in 1917.[6] George Hudson followed this placement when he discussed and illustrated this species in his 1928 publication The butterflies and moths of New Zealand.[7] In 1971 J. S. Dugdale placed this species in the genus Helastia and this placement was confirmed by Robin C. Craw when he revised the genus in 1987.[8][1] Dugdale agreed with this placement in his 1988 publication Lepidoptera - annotated catalogue, and keys to family-group taxa.[9] The male lectotype is held at the Natural History Museum, London.[9]

Observation of H. farinata.

Warren described this species as follows:

Forewings: grey, with very fine dark irroration ; the lines blackish; first near base, angled in cell and preceded by a finer line ; second line beyond one-third, angled on the subcostal, then oblique inwards and waved to inner margin before middle, followed by a similar finer line, the two marked with black on the median ; outer line at two-thirds, angled on vein 6, bidentate below median, then incurved and wavy, preceded by a similar finer line ; submarginal line pale grey, denticulate, with a darker grey shade on both sides ; fringe grey, slightly mottled with dark, with no dark basal line ; in the pale spaces before and beyond the central fascia, and in that fascia itself, traces can be seen of darker transverse lines; the space between the double lines forming the edges of the central fascia is filled up with blackish from the costa to the angulation.

Hindwings : paler grey, with traces of a sinuate still paler submarginal fascia with a dark line through it.
Underside: grey, with the outer line blackish. Head, thorax, and abdomen all grey ; forelegs blackish, with white joints.

Expanse of wings : 26 mm.[3]

This species is endemic to New Zealand.[10] H. farinata is found in the North Island only in the Bay of Plenty, Taranaki, Gisborne, Hawkes Bay and Wellington regions.[1] Although George Hudson records in 1939 that this species was observed in Awapiri, Marlborough, Craw pointes out that in Te Papa there is a faded specimen of Dichromodes sphaeriata which may have led Hudson to this conclusion.[11][1]

The preferred habitat of H. farinata is shady and damp forest ravines.[1]

Adults of this species have been observed to be on the wing in January, February and September.[12] Adults are nocturnal and are attracted to light.[1]