Last modified: April 19, 2020, 11:16 a.m.
A fairly common species throughout Belgium, more distributed in the northern part.
C. alnifoliae is ochreous to light brown with a grey tinge. The antennae are ringed alternately white and brown to 5/6 of the top while the remaining part is uniformly white. The wingspan is 12–14 mm.
The white caterpillar has a dark-brown head.
This species builds a slender, brown, spatula case cut out of a leaf. In May, the fully grown case is about 13 mm long. The mouth angle is circa 15°.
See also bladmineerders.be.
The eggs are deposited on the underside of a leaf of the host plant.
Before wintertime, mostly in September or October, the larva makes two consecutive youth cases before wintering. It resumes feeding in May, making the final case –in which it also pupates– in June, preferably on a twig and less often on a leaf.
The adults fly in June and particularly in July.
This species occurs everywhere in places with Alnus trees.