Elachista trapeziella

Description

Elachista trapeziella is a moth of the family Elachistidae. It is found from Fennoscandia to the Pyrenees and Italy and from Ireland to Slovakia. The wingspan is 8–10 millimetres (0.31–0.39 in). Adults are on wing from June to August. The larvae feed on Luzula luzuloides, Luzula pilosa and Luzula sylvatica. They mine the leaves of their host plant. At first, the larvae creates a narrow corridor which runs parallel to the leaf venation, although it may change direction two to three times. Later, this gallery abruptly changes into an elongate blotch, generally destroying the original gallery. Larvae may vacate the mine and restart elsewhere. Pupation takes place outside of the mine. They are pink with three cream-coloured length lines and a black head. Larvae can be found from autumn to April or June of the following year.