Eudonia octophora is a species of moth belonging to the family Crambidae. It was named by Edward Meyrick in 1884. It is endemic to New Zealand and has been observed in both the North and South Islands as well as the Chatham Islands. This species is known to inhabit wetlands and its larval plant host are species within the genus Juncus. Adults are commonly on the wing from October until May and are attracted to light.
This species was first described by Edward Meyrick in 1884 and originally named Xeroscopa octophora. He described this species more fully in 1885. He used species collected at various locations in the lower half of the South Island. George Hudson discussed and illustrated this species under the name Scoparia octophora, though his illustration was regarded by John S. Dugdale as dubious. In 1988 Dugdale placed this species in the genus Eudonia. The male lectotype specimen, collected at Castle Hill, Canterbury, 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 both the North and South Islands as well as the Chatham Islands.
This species is known to inhabit wetlands with rushes present. The larval host plant are species within the genus Juncus.
Adults have been recorded on wing most commonly between October and May. Adults are attracted to light.