Last modified: Jan. 28, 2020, 12:29 p.m.
An uncommon species throughout Belgium.
This species is rather big: 14–20 mm. The forewings are white, a little darker at the tip. Also with very fine yellow stripes on the veins.
The antennae have at the base a tuft of hair. They are alternately ringed black-brown and white till the tip.
The full-grown larva lives in a black pistol case of about 8 mm, with a mouth angle of 90°. The case is covered by a silken mantle that hangs from its rear end and almost covers the case (see foto).
See also bladmineerders.be.
The larva mines the leaf from the underside, making many, unusually small blotch mines, up to about 30 together. It hibernates and later pupates in the case fixed in a sunny position on the upper surface of a leaf. Larvae are fully grown in early June. The adults come to light.
The adults fly in one generation a year; onwards from late July towards August.
Monophagous on Quercus.