This species is on the wing from the middle to the end of October and lives in forest with a high rainfall.

[2] Gibbs described the adults of this species as follows: Large size (fwl ca 6 mm); fw with a number of narrow transverse whitish fasciae, dominated by a broad white fascia at 1/3 with kink toward anal margin, heavily shaded with dark brown scales on proximal side.

[2]The adults of this species differ from S. heighwayi as they have darker, more strongly marked appearance to their forewings with a dark brownish base colour.

[2] This species is endemic to New Zealand and is known from Lake Matheson in Westland and also Grono Spur on Secretary Island in Fiordland.

[2] The larval host species is the liverwort Plagiochila deltoidea which, as a result of the high rainfall in the localities where S. weheka is found, can grow up the trunks of trees.