The larvae of I. rufistriga feed on various host species including Urtica australis and have been reared on Rumex obtusifolius, Stellaria media and Rheum rhabarbarum.

[2] The male holotype specimen was collected at Reef Point on Antipodes Island and reared by Brian H.

[2] The larvae of this species have been described as pale green becoming reddish and as they mature they have a "broad white lateral band and three thin white dorsal lines on a dull green / brown ground colour, with rows of black dots dorsally".

[3][2] The mature larvae were described by Brian H. Patrick as follows: larvae were up to 42 mm long, dorsally dull yellow-green with a double black dorsal line, sub-dorsal black line with a row of green dots within it.

[2] The larvae of I. rufistriga feed on various host species including Urtica australis and have been reared on Rumex obtusifolius, Stellaria media and Rheum rhabarbarum.