The flax weevil was described by Albert E. Brookes in 1932 based on a series of specimens sent to him by Ernest Richard Fairburn.

[1] Specimens can range in colour from coppery-brown to dark brown, or even black in older weevils that have lost their scales.

[2][5] In the Tararua Range and on islands in Dusky Sound it lives on mountain flax/wharariki (Phormium colensoi).

Adults are nocturnal and hide among the dead flax leaves at the base of a plant during the day, emerging at night to feed.

They gradually darken to a black colour prior to the larvae emerging.

The yellow larvae move towards the fan of leaves near the plant base, where they tunnel into the soft tissue within.

[6] The flax weevil is legally protected under Schedule 7 of the 1953 Wildlife Act, making it an offence to collect, possess or harm a specimen.