Mnesarchella ngahuru is a species of primitive moth in the family Mnesarchaeidae.

This species is endemic to New Zealand and is found in the Taupō, Gisborne and Wellington regions.

[1] This species is very similar in appearance to its close relatives such as M. acuta, M. falcata and M. hamadelpha but can be distinguished by the shape of the male genitalia.

[1] Gibbs describes the colour of the male forewings as follows: Forewing 3.6–4.1 mm; dark-brown costal streak very broad with broad apex which is continuous with oblique anal fascia, basal area ochreous-white, grading to pale orange-brown toward dorsum; median costal patch ochreous-white, clearly defined; a patch of intense white scales in centre of median area; subapical area orange-brown, often suffused with ochreous scales.

[1]Although occurring in the same range as M. loxoscia and M. falcata, adults of M. ngahuru are normally on the wing at a later time.