Box tree moth caterpillar (Cydalima perspectalis), also known as Box moth, Box tree moth and Buxus moth is an all-too-common pest of the humble box hedge, Buxus sempervirens. And right now its active in Buckinghamshire and Hertfordshire. Having dealt with it for clients in the last week I thought it was a great time to post about how I can help you deal with it in your garden.
The first step is identification. Chances are if you are reading this you have already identified it, but it’s worth knowing how to spot the difference between Box blight and the moth, as well as how to spot it before it becomes a real problem.
One of the key differences between blight and box moth is the distinctive spider web effect created by the caterpillars, as well as caterpillar droppings (see image below!). Severe attacks can coat the entire hedge in spider webs, and usually small greenish pellets (the caterpillars droppings) are found in the webs. Blight is more likely to show die off and bare stems without any of the above.
Note: It is possible to have both Blight and Box Tree Moth at the same time
The moth is active between March and October so its essential to keep an eye on your box hedges during those times.
When walking past I will quickly run my fingers through and tease apart some of the hedges to look for caterpillars. Take a good look in there, particularly if you see even smaller spider webs, as this could be the beginning of an infestation.
There are other ways to identify these pests early, such as box moth pheromone traps. You might have seen them in botanical gardens, hanging from branches close to the hedging. I have had mixed results with them, but in gardens with a lot of box, or particularly sentimental box then it’s certainly worth a try. They aren’t too expensive, and you can get them online and in any good garden center. Keep a regular check on the traps – but not forgetting to physically check the hedge too! – so you can start treatment at the first sign of adult moths.
Once identified you can start treatment. The way I, and many professionals and botanic gardens I know control the caterpillar is to use a bacterium called ‘Bacillus thuringiensis’. Being a bacteria this is considered to be an organic solution. Before we go any further, you should understand a couple of things: Professionals applying any ‘pesticide’ or ‘herbicide’ products, even ones that can be bought off the shelf, MUST be licensed to use pesticides. This is the law in the UK. I hold a PA1/PA6 Use of Pesticides license and the relevant insurances. This is the required license for using these products in any kind of commercial or business setting. Having the license is great news for you as a customer, because not only does it give me the knowledge in applying these correctly to get the best results, but it also gives me the knowledge of how to apply them to keep YOU, your children, your dog, and your other non-target plants safe.
If you have box tree moth issues in your garden then please do get in touch today!