The box tree borer is a persistent pest that threatens the popular box tree in gardens and parks. Its caterpillars eat the leaves and can cause a lot of damage in a short period of time. Below you will find out which methods and means have proven to be particularly effective in combating the box tree borer.
They are green, black, well-camouflaged caterpillars that turn into dainty white butterflies after pupation. That’s nice in itself, but box tree moths are a nuisance for garden owners. As the name suggests, the pests attack box trees and can destroy them completely – if the infestation is not detected in time. The best protection for your trees is therefore prevention.
Once the boxwood borer is there, there is an effective and quick way to stop the infestation and prevent the boxwood from dying: Bacillus thuringiensis, a biological insecticide that causes the caterpillars to die within a few days. At the same time, the bacterium does not harm bees or other beneficial insects. It is also recommended by the Federal Environment Agency for environmentally friendly control of the box tree borer.
It is important to follow the respective product instructions exactly. It is best to spray the product generously onto your boxwood trees and make sure that you also wet the inside of the tree with the product. In the following table we show you popular products that are specifically designed for the boxwood moth.
When is the borer coming?
In this country there are around two to three generations per year between March and October. During this period you should regularly inspect your boxwoods for signs of infestation.
How do you recognize the infestation?
The infestation cannot be recognized immediately. First, the female moths lay tiny eggs (up to 150 per female) on the underside of preferred young leaves. After about three days, the larvae hatch and begin to eat. Preferably the leaves and bark of box trees. Once this stage is reached and the larva develops into a caterpillar, there are clear signs of an infestation:
How can you prevent?
There is no 100% protection against infestation. But you can at least take preventive measures on a small scale. Fine-meshed plant protection nets are best suited here.
Are there natural predators?
Since the boxwood is a poisonous plant and the caterpillars absorb the alkaloids when they eat the tree, there are not many predators. However, since the East Asian pest was introduced, some local birds such as great tits and sparrows have adapted to eating it. Other predators include hornets, wasps, bats and predatory spiders. So if you create a good habitat for the predators, you can also curb the spread.
The original for this article “Box tree moth – this is how you fight the dreaded pest” comes from chip.de.