[1] It is endemic to New Zealand and has been found in scattered locations in the North, South and Stewart Islands.

I. pelanodes is easily confused with I. skelloni as the two species are visually extremely similar.

This species was first scientifically described by Edward Meyrick in 1931 using a male specimen collected by George Hudson in January at National Park.

[4] In 2019 Robert Hoare undertook a major review of New Zealand Noctuidae species.

Forewings somewhat elongate triangular, termen rather obliquely curved, hardly waved; grey irrorated white and black and irregularly mixed dull green, edges of markings partially roughened; dorsal edge mixed red-brown; subbasal line partially edged black, a green spot following this beneath cell; first line nearly straight, partially edged black; orbicular subquadrate, laterally edged white and then black, reniform subquadrate, formed by a green bar between two black ones followed by a white blotch edged black posteriorly, beyond this a reddish-brown space, space between them tinged reddish-brown, claviform represented by a rounded reddish-grey spot edged posteriorly white and then black, four white dots on costa beyond middle surrounded black; second line formed by a contorted grey streak irrorated white, edged anteriorly by some blackish scales; subterminal slender, whitish, shortly angled towards costa and shortly bidentate beneath middle, in disc edged anteriorly green suffusion mixed black towards middle, on dorsal third suffused pale rosy-brown and preceded by a subcrescentic dark fuscous blotch, posteriorly edged blackish suffusion except towards extremities, on costa edged black anteriorly: cilia light brownish, slenderly barred whitish, a dark grey antemedian and red-brown apical line.

[2] Also I. pelanodes tends to be darker in appearance and female I. skelloni forewings often have paler pinkish ochreous colour in comparison to the other species.