Carpinus betulus, Belgium, prov. Namur, Viroinval, Treignes, Tienne d’Al Vau: larva, dorsal © Stéphane Claerebout.

ventral

Corylus avellana, Epen © Arnold Wijker: larva, dorsal view

As is evident from the picture by Arnold Wijker, the pair of black spots on the pronotum, considered to be diagnostic of the species, may be missing. Because the age of the larva does not seem to be very different from the other illustrated larve, most probably it is a matter of variability.