Sabatinca caustica is a species of moth belonging to the family Micropterigidae.

This species was first described by Edward Meyrick in 1912 using specimens collected in October at Seaward Moss, Invercargill by Alfred Philpott.

[2] The lectotype specimen, designated by J. S. Dugdale in 1988, is held at the Natural History Museum, London.

Forewings ovate-lanceolate, costa moderately arched, apex pointed, termen extremely obliquely rounded; violet-coppery-ochreous, in one specimen largely suffused with whitish; in one specimen a spot of dark purple-fuscous suffusion on dorsum towards base, one in disc beyond middle, and some irregular marking towards termen, and in the whitish-suffused specimen the dark purple-fuscous suffusion forms a blotch along anterior portion of costa connected with a large oblique blotch in middle of disc, a streak along dorsum from base to 2⁄3, a subterminal fascia enclosing a white spot on costa and a mark along termen in middle, but in the other two specimens there are no markings : cilia golden-ochreous.

[6] This species is found in Southland, including in the Takitimu Mountains, and at Stewart Island / Rakiura.