Last modified: Dec. 5, 2024, 12:14 p.m.
A very rare species in Belgium, but found troughout the country.
Native
Eggs are deposited at the underside of a leaf.
Initially the caterpillar is greenish brown but with ageing it becomes dark brown. The head is black.
The caterpillar builds a sloppy built case composed of larger leaf fragments and can reach a size of about 7–8 mm. After hibernation the case can have a two-tone appearance caused by the addition of new and fresh leaf fragments to the case. The mouth angle is 40–45°.
See also bladmineerders.be.
The eggs of this species are laid on the underside of leaves where the young larvae also start to mine from the beginning of October. They overwinter in their case attached to a leaf or twig, resume feeding in April, and are full-grown by the end of May.
The adults fly in one generation during June and July.
Alnus is the most important food plant, but also observed on Betula, Corylus or Carpinus.