Thank you very much for your reply. Like many species P. sericata might prefer a different primary foodplant n different biotopes /areas. In the UK it is most often found on Lonicera e.g.. And of course we should not think in countryborders when describing differences in foodplant preference. This is for me often the problem with literature inwhich all plants on which a caterpillars has been seen/found are called foodplant without making a difference in usage or preference. Let's take the Furcula's as a clear example I am sure that bifida is mainly (only?) a Populus-species and furcula mainly a Salix species.... in the literature often Populus and Salix are mentioned for both species without mentioning a difference in usage.
All the best,