Bucculatrix demaryella (Duponchel, 1840)

birch bent-wing

mine

The mine begins at an oval, lower-surface egg. Here begins a short, full depth corridor, often along the midrib or a thick vein. Most of the mine with a thick frass line. The larva soon leaves the mine, and starts causing window-feeding, later earing holes in the leaf. The larval chamber (the space occupied by the larva, while in the mine, obviously free of frass) is more than three times as long as wide. Pupation in a slender, greyish brown cocoon with c. 10 sharp length ridges.

hostplants

Betulaceae, oligophagous

Betula nana, pendula, pubescens; Corylus avellana.

In the Benelux mainly (exclusively?) on Birch. Patočka (1996a) and Biesenbaum (2010a) additionally mention Acer, Aesculus hippocastanum, and Castanea sativa, but this may refer to cases of xenophagy.

phenology

Bivoltine; hibernation as pupa.

BENELUX

BE recorded (Phegea, 2009).

NE recorded (Kuchlein & de Vos, 1999a; Microlepidoptera.nl, 2009).

LUX recorded (Ellis: Dudelange).

distribution within Europe

Europe, except the Iberian Peninsula, parts pf the Balkan Peninsula, and the Mediterranean Islands (Fauna Europaea, 2009).

larva

The mining larva is pale yellow with a darker head (the free living larva is grey green).

pupa

Described byPatočka (1996a), Patočka & Turčáni (2005a).

Young mines of the common Rhamphus pulicarius may deceivingly resemble demaryella mines, especially when they are situated in a vein axil, as often is the case. Rhamphus mines never have an exit hole, because the larva remains in the mine. Below a few pictures of the look-alike: