To get rid of it, you have to understand the box tree moth. Here you will find everything you need to recognize and fight the voracious caterpillars.
Have you observed discolored leaves, dead branches, white webs, and caterpillars on your box tree (Buxus ) – or have you noticed these symptoms in the neighborhood? It may be an infestation with the notorious box tree moth (Cydalima perspectalis ). Now is the time to find out more and act quickly to minimize damage to your bushes.
The box tree moth is an invasive species from East Asia. It was introduced to Central Europe a few years ago and specializes in our boxwood, which in many areas leads to complete baldness. This overview article briefly informs you about when the box tree moth appears during the year, how you can recognize and control it, and what influence the time has on the success of the control.
Box tree moth: Occurrence during the year
The problem with the box tree moth is that it leads to a rather hidden existence. The moths are nocturnal, so the egg-laying happens unnoticed – unless you use a suitable pheromone trap. With a pheromone trap like the Plantura moth trap, you can detect an infestation at an early stage. Directly below this paragraph, you can see a table which shows the development of the moth over the course of the year. Unfortunately, this is not a generally valid representation, because the speed of larval development is temperature-dependent, among other things. Even a very mild or very harsh spring can cause a shift of a few weeks. The observation of the butterfly flight with traps and the regular control of the bushes between March and September is therefore unfortunately the only reliable way to notice an incipient infestation in good time.
|State of development||Caterpillars (overwintered)||Cocoons||Moths, eggs||Eggs, caterpillars||Cocoons, moths||Butterflies, eggs, caterpillars|
|generation||Generation last year||Generation 1||Generation 2|
Recognize the box tree moth
Fortunately, the detection of yellow and dead shoots is possible long before the appearance of yellow and dead shoots in the bush: The yellowish borer eggs are in the outer areas of the box tree, in tightly packed “ice mirrors”. Only a few millimeters of large larvae hatch from them. They are rather light and green-yellow in color and have a typical black head capsule.
Immediately after hatching, they make their way into the sheltered interior of the shrub to hide in webs and scrape at the poisonous boxwood leaves. If they have grown a little larger and have several molts behind them, the color of the caterpillars of the boxwood moth changes a little into the dark and the characteristic black and white markings emerge.
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Now they leave the inside of the boxwood and go back to the outside areas. After 6 larval stages, pupation finally follows, also hidden in webs. The resulting small butterfly is usually brightly colored. He cares for the next generation of voracious caterpillars. We have developed detailed articles with pictures for you, which exactly describe the eggs of the moth, the associated caterpillars, and the boxwood moth moths. You can find out more about recognizing the moth in this special article. If, after reading this description, you suspect another disease of your box tree, you can find out about other diseases of Buxus here inform.
Summary Recognizing the box tree moth:
- If the infestation is severe, smaller or larger sections of the branch will die off.
- An infestation can be recognized much earlier on webs and the maximum 5 cm long caterpillars. The caterpillars are green-yellow, later with black and white markings and white bristles. The blackhead capsule is typical.
- The eggs are yellowish and several are deposited in the outer areas under the leaf.
- The approximately 4.5 cm wide moths are not always colored the same, mostly they are light with black wing edges.
Fight the box tree moth
If you recognized the infestation early or if it is weak, we recommend reading this special article on effective home remedies for combating the box tree moth. It describes measures that work – such as the high-pressure cleaner – and less effective approaches – such as baking soda. But if you are already standing in front of a dying box tree full of caterpillars – you no longer have to start collecting.
Read also: How To Get Rid Of Oak Processionary Moth
You can now decide: Are you looking for alternatives for the boxwood or do you try to combat the moth? You can find out here how the control of the borer works in general. If you have no interest in combating caterpillars with poison, you will find biological ways here that achieve good results without chemicals. The use of nematodes, neem oil, and preparations containing Bacillus thuringiensis are far more promising than the environmental compatibility of these products suggests.
Conventional means are often also effective – however, reducing important beneficial insects in the garden often creates new problems with pests. We recommend that you always carefully compare the package insert with the official requirements before buying a plant protection product.
Tip: You don’t have to worry when you collect and dispose of the box tree moth. The caterpillars are not poisonous if they come into contact with the skin. But you shouldn’t eat them – it’s better to wash your hands after contact. Because inside, the animals harbor several toxic compounds that they have ingested from the also poisonous boxwood. In our article “Are the boxwood moth poisonous?” learn more about the toxicity of the borer.
When is the best time to fight the borer?
The following applies to the borer: The choice of the point in time determines the success of the fight. If you apply a spray against the caterpillars, although they are still well wrapped in their leaf webs, you should not expect a reduction in the infestation. The same applies if the moths are still present as eggs or already as cocoons. So when does it make sense to inject remedies against the box tree moth or use something else? This article will guide you when it comes to controlling the box tree moth.
Fight the box tree moth biologically
If you are looking for an effective, simple, and yet environmentally friendly control method, you should use our Gardender borer-free is used in organic farming and is professionally managed ornamental and vegetable gardens because it has no effects on beneficial insects or humans. Unlike other available sprays, it only works against the caterpillars of certain butterflies such as the borer.
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The active ingredient contained is persistence spores of a specialized bacterium, the Bacillus thuringiensis. If these are applied to the leaf of the infested plant, they can be ingested by caterpillars while they are eating. In the intestine, the bacteria release a toxin that not only stops eating immediately but also causes the caterpillars to perish after a maximum of five days. Because of the high specificity, safety for the user, and good effectiveness, we recommend using this biological spray.
Tip: You can also make pome fruit trees and cabbage plants caterpillar-free with our Gardender borer-free – here the large and small cabbage white butterfly is fought with the agent.