Erechthias chasmatias is a species of moth in the family Tineidae. It was first described by Edward Meyrick in 1880. This species is endemic to New Zealand and is found in the North Island. This species inhabits native bush. Adults are on the wing from October to April and have been collected by beating small trees and foliage.
It was first described by Edward Meyrick in 1880 using two male specimens taken in forest at the Wellington Botanic Garden in January and named Erechthias chasmatias. In 1915 Meyrick placed this species in the genus Hectacma. In 1927 Philpott studied and illustrated the male genitalia of this species. George Hudson discussed and illustrated this species in his 1928 book The butterflies and moths of New Zealand under that name. In 1988 John S. Dugdale synonymised Hectacma with the genus Erechthias and thus this species returned to the name Erechthias chasmatias. The male lectotype is held at the Natural History Museum, London.
Meyrick described this species as follows:
This species is endemic to New Zealand. This species has been observed in the North Island. It is relatively common in Wellington having been observed in both the Wellington Botanic Garden and a à Âtari-Wilton's Bush.
This species inhabits native forest. Larvae of species in the genus Erechthias feed on dead plant debris or the tough leaves of plants such as palms.
The adults of this species are on the wing from October to April but are most commonly observed in November to January. They have been collected by beating the trunks of small trees.