Last modified: Feb. 24, 2023, 4:59 p.m.
A very rare species in Belgium.
The egg is deposited on the underside of the leaf.
The mine starts as a very contorted gallery on a small surface. The frass in that part of the mine is reddish. Further on the gallery widens into a very wide gallery or a elongated blotch where the black frass is dispersed.
See also bladmineerders.be
The cocoon is blackish brown.
The adults are on the wing in May and June.
The host plants are: Betula and occasionally Coryllus avellana.