Detect, treat & prevent: Box Tree Borer
Do you have boxwood in your garden? Then this article is for you!
What are box tree borers?
Box-tree borers (or boxwood borers) are moths, whose caterpillars feed of boxwood leaves. Although they are small, they can cause a lot of harm to your box trees, so it is important to act quickly and with the right products!
Boxwood borers are an issue almost all year long. Generally, caterpillar larvae come out beginning of spring and eat the leaves and wood. A month later, they become moths that lay hundreds of eggs all throughout summer. These eggs hatch after a couple days and the cycle repeats itself. There can be up to 3 generations a year. In winter, caterpillars build their cocoon and wait to come back in spring.
How to recognise box tree borers?
The caterpillars have a black head and a green body with black dots. However, it can be difficult to spot them as they are usually in the centre of the boxwood and blend into the colour of the tree.
The moths are very small with white and brown wings. They usually come out at night and fly around the boxwood.
If your boxwood is infected, you will notice webs all round it. If by looking at your boxwood plant you can easily find a few webs, you can be sure that it is full of caterpillars, and it is time to act.
You might also detect boxwood borers if leaves turn brown. An effective way to detect them is also by placing a pheromone trap, that will attract and catch the moths.
How to treat box tree borers?
The first step is to cut off and prune about half the height of the shrubs. Although this cut might seem significant, it is not an issue for the boxwood as it sprouts new branches very easily. These branches must be disposed of immediately. It is also helpful to try and take a few caterpillars off by hand although it is nearly impossible to get them all.
A trick you could use it to place a tarp under the tree and shake it or spray it with water so that caterpillars and eggs fall of.
Alternatively, insecticides & pheromone-based traps are also a great way to treat and/or prevent infestation.
How to prevent box tree borers?
Although treatments methods exist, prevention is the best method in terms of cost and effectiveness.
At the start of spring, inspect your boxwoods to make sure that no caterpillars have emerged from their overwintering stage. If this is the case, use an insecticide designed for this purpose.
Place a pheromone trap next to the boxwood that will catch moths and will inform you of their presence.
An increasingly common pest, Boxwood Moths can cause significant damage to box shrubs. Buxatrap helps eliminate this problem so that your box shrubs can flourish, through biological control using pheromones to trap these pests before they can do any damage. The trap can provide season long protection over 180sqm, with active pheromones lasting for up to 3 months, before needing to be refilled additional pheromone cartridges.