Elachista biatomella

Description

Elachista biatomella is a moth of the family Elachistidae. It is found from Sweden to the Iberian peninsula, Sardinia and Italy and from Great Britain to Ukraine. The wingspan is 7–9 millimetres (0.28–0.35 in). Adults are on wing from May to September in two generations per year. The larvae feed on Carex acuta prolixa and Carex flacca. They mine the leaves of their host plant. The mine starts at a leaf axil and ascends as a narrow corridor with a thin frass line. After 20–30 millimetres (0.79–1.18 in), the direction of the mine reverses, resulting in an elongate and lightly inflated blotch. Pupation takes place outside of the mine. Larvae can be found from June to July and again (after overwintering within the mine) from September to April. They are yellowish with a dark brown head.