I. stulta is also darker than specimens of I. acontistis obtained in the southern parts of the South Island.

I. stulta is also very similar in appearance to I. emmersonorum but the later species has darker forewings and is more strongly marked on the thorax.

It has been recommended that a comprehensive survey be undertaken in spring in the wetlands and shrublands surrounding Invercargill in order to attempt to rediscover this moth.

Head, palpi, thorax, and abdomen pale-fawn; dark line on collar, suffusedly bordered with whitish.

Forewings slightly dilated; costa uniformly arched; apex round-pointed; termen slightly oblique, rounded; pale-fawn; markings dark reddish-brown; a short streak from near base beneath to 1⁄4; a suffused irregular streak from middle of base to termen above anal angle, almost interrupted before middle; a suffused streak from 1⁄3, attenuated anteriorly and much dilated towards termen, divided on lower portion by whitish borders of veins; one or two short apical streaks above this; cilia brownish on termen, fawn beneath.

[2] This may be the result of habitat loss or changes in plant composition in this part of New Zealand, particularly the reduction in wetlands and shrublands.

[2] Hoare recommends a survey of the remaining shrubland and wetland habitats in spring to try to find this moth.