Ichneutica Epiastra

''Ichneutica epiastra'' is a moth of the family Noctuidae. It is endemic to New Zealand and is found throughout the North, South and Stewart Islands. This species prefers open habitats such as wetlands, dunes and forest clearings. Eggs are laid in the summer or autumn and larvae feed during winter and spring. The larval host species are found within the genus '' Austroderia.'' The adult moths are on the wing between October and February. Adult ''I. epiastra'' can possibly be confused with the similar species ''I. arotis'' and '' I. haedifrontella'' however there are differences in appearance that enables ''I. epiastra'' to be distinguished from these two species. In particular ''I. epiastra'' has long sharp-tipped ‘horns' on its head that are diagnostic. The adults of this species appear reluctant to be attracted to light although they do come more frequently to the brighter mercury vapour traps.

Taxonomy

This moth was first described by Edward Meyrick in 1911 and named ''Leucania epiastra''. The male lectotype specimen is held at the Natural History Museum, London. In 1988 J. S. Dugdale, in his catalogue on New Zealand lepidopera, placed this species within the ''Dipaustica'' genus. In 2019 Robert Hoare undertook a major review of New Zealand Noctuidae species. During this review the genus ''Ichneutica'' was greatly expanded and the genus ''Dipaustica'' was subsumed into that genus as a synonym. As a result of this review, this species is now known as ''Ichneutica epiastra.''

Description

George Hudson described the eggs of ''I. epiastra'' as follows:

Hudson went on to describe the larva of this species:

Hudson goes on to state that the pupa appears light brown in colour initially and then turns a shiny very dark brown.

Meyrick first described the adults of this species as follows:

Hudson also described the adults of this species:

This species is variable in both colour and size. The colour of adults of this species can range from pale to pink ochreous up to a deep brown. The adult male wingspan is between 33 and 43 mm and the female wingspan is between 38 and 45 mm. There are specimens that have been collected at Ōkārito in Westland that are regarded as a dwarf form of ''I. epiastra'' as they are very similar both in appearance and in genitalia but are smaller than the typical ''I. epiastra.'' The dwarf Westland form male has a wingspan of between 32 and 33 mm and the female has a wingspan of 32 mm. ''I. epiastra'' can be confused with the similar species ''I. arotis'' and '' I. haedifrontella''. ''I. epiastra'' has small projections on its head that are diagnostic though these are sometimes difficult to discern. In comparison to the other two species these tubercles are long and sharp tipped. A row of black dots can be seen on the forewing of ''I. epiastra'' where as ''I. arotis,'' has faint dashes, if any markings at all, on a similar part of its forewings. ''I. haedifrontella'' only has short and blunt tubercles on its head. This is the only visible feature that distinguishes ''I. haedifrontella'' from ''I. epiatra'' although male ''I. haedifrontella'' have distinctive genitalia that can be seen via dissection.

Distribution

''I. epiastra'' is endemic to New Zealand. This species is found throughout the North, South and Stewart Islands.

Habitat

This species lives in open habitats such as wetlands, dunes and forest clearings.

Life history and behaviour

Eggs of this species are laid in summer or autumn and larvae feed during winter and spring. The larvae feed at night. During the day larvae hide in the bases of the leaves of their host species. When ready to pupate the larva journeys to the flower stem of its host, eats into the internal part of the stem and makes a chamber at the joint. This is where the larva spends several weeks before pupating. In preparation, just prior to pupating the larva will create a hole at the top of the chamber leaving only a thin layer of plant material to cover the hole. After approximately six weeks the adult moth emerges - normally in the evening between 7pm and 9pm. Adults are on the wing between October and February. This species appears reluctantly attracted to light. It does however come more frequently to the brighter mercury vapour traps.

Host species

The plant host species for the larvae of ''I. epiastra'' are in the genus '' Austroderia''.

References

{{Taxonbar, from=Q104215849

Hadeninae
Moths of New Zealand
Endemic fauna of New Zealand
Moths described in 1911
Taxa named by Edward Meyrick
Endemic moths of New Zealand