A few days ago, our local moth expert posted a fascinating thread on Twitter/X about the population explosion of the non-native invasive Box tree moth (Cydalima perspectalis) in Cardiff. As George noted, this moth was first recorded in Kent, England in 2007, and spread rapidly across the southern counties of England before arriving in Cardiff in 2018. George runs a regular moth trap in his garden and, though the moth didn’t appear in his trap until 2020, by 2023 it had become the most common species he trapped.

This rapid escalation in adult moths means, of course, that there has also been a huge increase in the numbers of moth caterpillars and, as a result, Box bushes and hedges are being decimated by the caterpillars’ voracious appetites. George talked about ‘widespread defoliation’ in Cardiff so I went looking at a location nearer to home where I knew there was a Box hedge. It wasn’t quite as bad as the reports from north Cardiff and there was quite a lot of new growth on the bushes but there were also huge numbers of caterpillars munching their way through the foliage. I imagine it’s only a matter of time before this hedge has been totally stripped of leaves.

It’s such a shame that the Box tree moth is so destructive as both the adult moth and the caterpillars are very attractive creatures. Apparently, many gardeners are already removing Box from their gardens so any gardeners out there, be aware, your Box (Buxus species) will be targeted by this moth when it spreads to your area.