Helastia triphragma
Helastia triphragma, also known as the angle carpet moth, is a moth of the family Geometridae. It was first described by Edward Meyrick in 1883 and originally named Cidaria triphragma. This species is endemic to New Zealand and is only found in the South Island. It inhabits native scrub in coastal, lowland and montane areas. The larval host plant of this species is Helichrysum lanceolatum. Adults are nocturnal and attracted to light.
Taxonomy
Edward Meyrick first described this species in 1883 using two specimens collected by Mr. Skellon in Blenheim and named it Cidaria triphragma. He gave a fuller description of this species in 1884. George Hudson discussed this species in his 1898 book under the name Hydriomena triphragma. He again used that name when discussing and illustrating this species in his book The Butterflies and Moths of New Zealand. In 1939 Louis Beethoven Prout discussed this species under the name Euphyia triphragma. Robin Craw, when revising the genus Helastia, placed this species within it in 1987. The male lectotype specimen, designated by Craw, was collected in Blenheim and is held at the Natural [History Museum, London].Description
Meyrick described this species as follows:Although similar in appearance to H. siris, H. triphragma has larger forewings which can help distinguish it from the other species.