Box Tree Caterpillar

Any keen gardener with box pants beware. We inherited some beauties and have woken up to see them eaten away. I looked it up & see it’s a fairly new caterpillar called the box tree. It needs hand removing if you catch it early or pesticide to stop the spread.

Try looking for info on which plants they go for. My DEFRA thing is from 2009, so probably too out of date.

Thanks for your information Brian.

I’m not sure & according to what I’ve now read on Google, it depends how bad the invasion is. Ours was a round plant in a big pot & by the time we noticed this morning it was beyond help. As we have several others we’ve burned the whole plant & will put insecticide on the others. As Brian says they reduce the leaves to skeletons in no time at all. I think that only box is affected thankfully but there were at least 29 caterpillars on the plant. I’ve examined the others, look user the leaves, and they look all right so far.

I think so. The people whose burning bush was eaten away lost it but then perhaps the caterpillars were still present and got the new growth. But that was the south of Switzerland where it is quite serious already. The DEFRA sheet I have says that the moths return though and the problem spreads from a small area quickly so are trying contain infections in the areas they are found in because of the speed. So, that gives no actual answer but I would do a web search to find out if I was you.

We have, what I think, is a box hedge that has lost all its foliage during the winter. However, not all the plants are affected and I see some signs of new growth on the original stems, but not on the side branches and twigs. Have I got this right or can the plant get over the problem?

Nasty little invader accidentally imported from China and now all over Western Europe. Look for the papery pupa which is a bit under 2cm long and remove leaves they are attached to, then burn them. Cut off branches with the webbing and caterpillars then get rid of them similarly. Insecticides containing bifenthrin or pyrethrins are used but both are suspected (yet to be proven) to be carcinogens. Bifenthrins are used in flea/tick treatments for domestic pets and there are some campaigns to have that stopped, so not nice perhaps. In the UK DEFRA wants all infestations of box and the few other shrubs they damage reported, but here you would need to find out. I saw some pretty awful damage in Switzerland a couple of years ago where all the burning bush leaves were eaten to a skeletal, stone dead state in just a couple of weeks. We have none of the plants that can be infected but good you made the alert anyway for everybody else.