At Aberdeen Country Park today to check out a tip from 特別懶散  (Thanks!)  Seems some larvae of S. pyretorum were observed a couple weeks ago heading across a grassy sward toward a specific tree.   Only thing is, the object tree is NOT the well known LFP of S. pyretorum, namely, Cinnamomum camphora 樟科（大喬木) nor the suitable alternative, Liquidambar formosana 金縷梅科（喬木）(Sweet Gum).  It was however, ID'd as Machilus chekiangensis  英文名稱 by Moviesorientate who also explained why the larvae likely chose that kind of tree.  Both the Machilus c. and Cinnamomum c. trees are in the same family:  Lauraceae.  

Question:  has anyone else seen S. pyretorum eating this tree or related species?

well, I'm about 85% sure it's Machilus chekiangensis, but I'm pretty new to plant ID, so here's a photo and I hope someone can give a confirmation : )

楠屬, may be!

yep I'd say it's Machilus sp too.