Last modified: Jan. 17, 2020, 4:03 p.m.
This species was mentioned in Belgium for the first time in 2009 and has since been reported for almost all over the country. It appears to be not not so rare and in some places it occurs in high numbers.
This species, having a wingspan of 5–7 mm, has a dark grey forewing and a distinct triangular white spot before the tornus.
The larva lives on Betula. When young it starts as a borer in the centre of a twig, later it enters the leafstalk and then the midrib of a leaf. When fully fed, it cuts out an oval case in which the larva drops to the ground.
The adults can be seen flying in sunshine around birch branches. They come occasionally to light.
The adults have been observed from early May till mid July.
The larva lives on Betula.