[4][5] George Hudson, following Meyrick, discussed and illustrated this species in his 1928 publication The Butterflies and Moths of New Zealand under the name Carposina exochana.

[2] The female holotype specimen is held at the Natural History Museum, London.

Palpi with upper longitudinal half ochreous-white, lower dark fuscous.

Forewings elongate, scarcely dilated, costa moderately arched, apex round-pointed, hind-margin faintly sinuate, rather strongly oblique; pale whitish-ochreous; about ten small irregular scattered black dots in disc; a subterminal series of irregular cloudy black dots, obsolete towards costa and inner margin : cilia pale whitish-ochreous.

[9][1] Other than its type locality of Nelson, H. exochana has been collected in Masterton, Wellington, Christchurch, Dunedin and Invercargill.