A true moth invasion has been on the rise in Germany and throughout southern and central Europe for some time. It endangers one of the oldest cultivated plants in domestic horticulture – the boxwood. A favorite of many avid gardeners, these shrubs are mercilessly attacked by the moths and larvae of the box tree moth (Cydalima perspectalis) destroyed. In most cases, this happens in just under two weeks. The aggressive pest came to Europe from Asia a good 10 years ago, presumably with the discounter boxwoods from China. Because of climate change, sometimes not the usual two, but a whole four new generations of box tree moths appear here in summer. A rapid spread that is described by many professionals as a serious disaster. In addition to favorable climatic conditions and lush greenery, the insects here have hardly any natural predators. You feel like you’re in Cockaigne. Nevertheless, you should not immediately resort to chemical pesticides. The following natural remedies and methods are available to you if you want to combat box tree moths.
Fighting box tree moths is also possible with natural means
Collect eggs and larvae
As with the larvae of other pests, the mechanical method of collection is somewhat helpful. This minimizes the number of eggs and larvae and prevents or at least postpones a total loss. You should therefore regularly check your plants carefully and free them from the box tree moths as best you can. The collected larvae and eggs are then either thrown into the water or burned. Never throw them in the compost or on the ground.
The caterpillars can grow up to 5 cm long
Algae Lime Powder
Cut back the boxwood bushes first. Many of the eggs and caterpillars are already removed in this way. Sweep up and burn the cut parts of the plant immediately. Then take the algae lime and spread the powder evenly over the boxwood. Algae lime is not only a perfect protective agent when fighting box tree moths, but also helps against fungal diseases and at the same time serves as a fertilizer for the plants. It is best to use this method at least three times a year so that your boxwood is better equipped against the pest.
Neem oil drives away the box tree moth
The neem oil emulsion (1 tablespoon of neem oil in 1 liter of water) is an effective, biological pesticide that is sold in organic garden trade as a natural plant care product. This remedy has a very characteristic odor that successfully drives away the box tree moth. The moths no longer visit the boxwood bushes to lay their eggs. In addition, the neem oil also fights the larvae directly by destroying their sensitive hormone system and causing them to die.
Leaves and fruits of the neem tree
In order to use the neem oil emulsion optimally, you should first cut back the boxwood, similar to the algae lime. Then generously spray the whole plant with the emulsion, not only from above, but also inside and from the underside. This gives the pests even less chance of getting to the leaves. Repeat the procedure at regular intervals and especially when it has rained.
Extra tip: The pruning can also be done from May and June. Just don’t forget to burn the cut leaves and twigs.
Neem oil can also be used against potato beetles
The foil method
This is a very simple way to rid your ball shrubs or smaller boxwood plants of the boxwood moth. To do this, you should wrap them as tightly as possible with foil or black garbage bags and leave them in the blazing sun for about two hours. Then give a cold shower with the garden hose. This shocks the larvae and moths and they fall off or even die out. Additional pruning will remove even more of this and help your plants recover from box tree moth infestation.
Extra tip: You can also do the washing up with a pressure washer.
These are special plastic containers that are filled with sex hormones and attract male moths. Once caught, they can no longer escape and fertilize the females. The number of laid eggs is thereby minimized in an ecological way. Some of the best pheromone traps for box tree moths include Solabiol from SBM Life Science or Neudomon from Neudorf.
Outwit the male boxwood moths
Extra tip: The biological spray powder Xentari is also a completely environmentally friendly means when it comes to fighting box tree moths. It is based on a bacterial protein, which kills the caterpillars in a natural, sustainable way. This is not only optimally effective against these pests, but also against winter moths and cabbage white moths. At the same time, Xentari is absolutely harmless to bees and other beneficial insects.
So, if you want to fight the box tree moth, don’t go straight to the chemical club, but try all possible natural means first. Be patient and don’t give up! This is the only way your boxwood bushes will get a chance against this aggressive invasion of borers.
Heavily infested boxwood bushes look like this
The box tree moth larvae are considered a real insatiable
They leave behind a dreary boxwood desert
But with the right tools and methods, you can save them