One got into the conservatory this evening, duly caught safely and evicted. Half an hour later there’s another in the conservatory! Definitely not the same one, second was smaller & had different wing markings). Also caught safely and evicted.
Last year when we where in South of France we went to a forest infested with the caterpillars of these evasive species. It was like a scene from an Indiana Jones movie, you couldnt walk 30cm without running in to 10’s of them dangling on its threads. The forest had been decimated by them. Europes much warmer than their native climate and they can get upto three breeding cycles in a season, hence why they are prolifereting across Europes amd devasting our natural box forests and ornamental gardens.
It seems somehow wrong to kill a moth, but the caterpillars are far easier. I only found them when I noticed that one of our box bushes had webs on it and was dropping leaves. I managed to find and squash 26 caterpillars and our other four bushes look Ok for now. We try not to use sprays but picking them off is rather time consuming and I hate killing any creature. We even save wasps from the house - they actually do an awful lot of good. Wasps of course are naturally part of our ecosystem whereas these box moths have been introduced, from Japan originally I believe so presumably have few or no predators. Squash them!!
Unrelated to box-tree moth, but I had one of these St. Andrews Cross Spiders outside my house 1.5 years ago. Because it was so colourful, I thought it must be very poisonous and quickly destroyed its web and sprayed around the area. She never came back since.
Later I discovered it is not poisonous so my perspective completely changed - she is actually pretty and great for keeping other insects under control so I kind of miss her. Always ask uncle google before getting rid of the creepy crawlies.
Spurred on by this thread I had a word (WhatsApp) with my microbiologist & RHS member daughter & she recons Box Tree Moth is now well established in UK & most probably almost impossible to eradicate.
She is very anti synthetic control but admits that in some cases it might be the only way.
Non pesticide controls do not really help other than reduce what you have, hand removal, biological controls, encourage caterpillar eating birds, or just don’t plant box.
Organic pesticide controls at the caterpillar stage are the most effective, high pressure spray is needed to penetrate the silk webbing & it needs repeat applications with contact insecticides (e.g. Bug Clear for Fruit, Ecofective Bug Killer).
Last resort is go to some of various synthetic controls (e.g. Westland Resolva Pest Killer, Provanto Ultimate Fruit Bug Killer & Py Bug Killer)
I checked my three bushes that form part of a mixed hedge, so far no sign, but I have Resolva ready.