The mature caterpillars look so much like birch catkins with markings similar to a hawk moth. I lost count the number of times I moved the caterpillars to a new sleeve only to find out later that I had missed one and found it eating outside my sleeve. When the caterpillars had grown to almost full-grown I placed cut branches into milk containers and blocked the entrance with paper. And placed the caterpillars and the branches into a large Exo Terra insect cage it was even more difficult to find the caterpillars hanging with the birch catkins. By placing my cut branches into a workbench I was able to get some nice pictures, showing their brilliant camouflage.
My healthy pupae will be the first to emerge as early as February, and I will probably take these to a forest to film them if all goes well.
Really looking forward to seeing and photographing the moths for the first time.
Now only found in Scotland and parts of Central Europe, as well as Silver Birch the Caterpillars will also feed on Hazel, Alder, Lime and Hornbeam.