I have a hawthorn hedge at the front of my house. This is kept well trimmed. Today I noticed a trail of brown web type substance, at the end I found some orange in colour caterpillars. Where the web was it looked like the hedge was dead, this may just be because the leaves had been eaten. Does anyone know what this is and how to treat it, will it kill my hedge or will it recover next year? It’s not a wide area but like a snake trail across the hedge.