Box tree caterpillar

Underneath the oak and beech at the bottom of our garden there are a number of box bushes, bushes which are now maybe twenty five years old, around eight feet high and more or less never pruned. Rather handsome, though I say it myself.

Unfortunately, last year they started looking a bit sickly and now they look very sickly, with the lower branches of most of the bushes being badly affected and largely defoliated.

After a quick look at the RHS site, I thought box blight, a fairly serious fungal pest, but then closer inspection of the bushes revealed some colourful green caterpillars, rather more than an inch long. Almost certainly the box tree caterpillar, a pest which has arrived in Europe - or more particularly around London - in the last ten years or so. A native of east Asia.

Presently wondering what to do. Not keen on sprays as the word seems to be that one needs a lot of it to get through all the webbing spun by the caterpillars. And most of these sprays contain all kinds of bad things, noxious to oneself as well as to caterpillars. Maybe the bushes will just have to go.

This snap turned up by Bing, with the caterpillars marked by the yellow cartouches, shows a bush in rather better condition than the lower reaches of ours.

There is a snap of a handsome moth at reference 1, but I have not seen one myself.

Reference 1: https://www.lovethegarden.com/uk-en/article/box-tree-caterpillar.