It looks very much as though iris has laid a remarkable number of eggs this year, and has wandered far and wide in the process.
Searching for larvae from early Sept through to late Oct after good egg lay flight seasons is an efficient way of finding new colonies. The larval damage, around leaf tips, is quite salient. Concentrate on bushes with mid-green coloured foliage which is soft and matt in texture. Avoid foliage exposed to mid day sun.
As well as carrying on my monitoring of egg / larval numbers in and around Savernake I'm going to visit some places where the butterfly has not recently been recorded, outside the butterfly's current known range. I particularly want to declare Swindon, Gloucestershire and Herefordshire Purple...
Today, I'm fairly certain I saw an adult iris, briefly and at a distant, gender uncertain, 20 mins after Pete Eeles left me. The trouble is that it didn't return, suggesting it wasn't male. Was it a vision or a waking dream?