Betula pendula, Castricum, head and thorax of a young larva dorsal..

.. and ventral

head and thorax of a full grown larva dorsal..

.. and ventral

Betula, Belgium, prov. Namur, Couvin, Pétigny © Stéphane Claerebout. This moulting larva demonstrates the transition from the black-spotted young larva to the entirely white full grown stage

The head is retracted into the prothorax to a large extent.

Young larvae have a dark pronotum and a central black mark ventrally on all sternites and abd. 1, ventrally.

Full grown larvae are white with an entirely brown head. Abdomen segment 1 has a of pair of short lateral extensions (Hering, 1957a); often they are hardly visible.

Bengtsson (2008a) depicts a larva with a black pronotum; this must have been a young larva.

15/04/2014