Fighting boxwood pests: Zünsler & Co.

As robust as the boxwood may seem, it is usually not spared from pests. We show how to recognize the symptoms and fight the pests.

If you look at the Boxwood (Buxus) thinks, when it comes to pests, the box tree moth usually comes to mind first. Unfortunately, he's not the only one who likes to mess about our book. We introduce the different pests and show how to fight them successfully.

Boxwood is not only affected by disease, it can also be attacked by pests. Small animals eat their fill of our plants and usually leave a sad picture. In the following we explain to you what you can do and who you are actually dealing with.

Box tree moth

One reason for corroded box trees are often the caterpillars of the box tree moth (Cydalima perspectalis), which originally comes from the East Asian region. In this special article on the Box tree moth.

Box tree moth: symptoms

The voracious caterpillars can be found on the boxwood bushes from mid-March. The butterflies, on the other hand, are rather inconspicuous with their white wings with brown tips, but their offspring are only too happy to attack our boxwood. The up to 5 cm long green caterpillars have sensational black spots and a black head capsule. First they eat windows in the box leaves and over time the caterpillars will eat all of the leaves and even shoots. Since they start from inside the bush, the infestation is not noticeable at first. The caterpillars later develop into a weave and your beloved boxwood is finally covered in a cobweb-like web.

Tip: Pheromone traps like that Plantura moth trap serve for the early detection of a moth infestation. In this way, you can take active action against the pest quickly.

Fight the box tree moth

If you regularly take a close look at your boxwood and also take a look inside the shrub throw, you will hopefully recognize the infestation early, because then control is still problem-free possible. A biological spray like ours is suitable for this Plantura borer-free XenTari^® outstanding. Sometimes there have been sightings that native birds have eaten the bitter caterpillars, but this is usually not enough.

In addition to biological sprays, you can also manually collect or spray the caterpillars with a Try a water jet, but always use gloves to be on the safe side, as the caterpillars are poisonous from the boxwood take up. It is not yet known to what extent these poisons are released by caterpillars. Therefore, you should use the Dispose of the boxwood moth larvae prefer to exercise caution. More about the successful Control of the box tree moth can also be read here.

Shoot tip mite on the box

Twisted shoots and leaves are caused by the shoot tip mite (Eriophyes canestrinii), which belongs to the gall mite family. In contrast to other gall mites, this one does not cause galls and growths, but rather deformations.

Shoot tip mites: symptoms

The shoot tip mites cause deformation of the boxwood shoots by sucking sap out of the plant cells. As a result, the leaves and shoots of the boxwood cripple and the leaves remain small, thin and grow twisted.

Fight shoot tip mites

The tip mites do not pose a serious threat to the Buchs, but are more of a visual problem. If you prune your plant regularly, you shouldn't have much of a problem with these mites. If you find individual shoots with the shoot tip mites, you can also remove them specifically.

A particularly susceptible type of boxwood to these gall mites is 'Green Mountain', but there are also varieties that are less sensitive to these mites - these include 'Herrenhausen', 'Faulkner', 'Hollandia' or 'Handsworthiensis'.

Spider mites on the box

Since 2000, a relatively new pest has been found on boxwood in Germany, which originally came from North America: the boxwood spider mite (Eurytetranychus buxi).

Spider mites: symptoms

These small spider mites can barely be recognized with the eyes on the leaves, because they are only 0.35 to 0.48 mm in size. The boxwood spider mite can multiply extremely quickly and form up to eight generations per year. The damage caused by these spider mites can be recognized by bright points and short lines that look like commas. This damage occurs when the animals suckle on the plant cells. If the infestation is very strong, all of the leaves become light and in the worst case the box tree sheds them completely. The mites can reproduce best on box trees when they are in sunny and warm areas Locations - but they also occur in shady places, they only multiply there slower.

Fight spider mites

These mites are fond of beneficial insects like Lacewing (Chrysopidae) or ladybugs (Coccinellidaei) eaten and also washed off the leaves by summer thunderstorms and thus clearly decimated. But if they are threatened with severe infestation, you can use oil-based sprays in autumn or spring against the wintering eggs of the spider mites. Unfortunately, no special varietal differences with regard to this pest could be found in the book varieties.

Boxwood leaf flea on the box

Another sucking pest that can affect the box is the boxwood leaf flea (Psylla buxi). The larvae and the adult animals are greenish in color and the larvae form a white wax wool under which they hide.

Boxwood leaf flea: symptoms

But how does the leaf flea infestation show up on the box tree? The leaf fleas suck on the leaves, excrete sticky honeydew and black sooty fungi then settle on them. In addition, the larvae form their white wax wool coat and protect themselves from enemies and from drying out. When the fleas suck on the leaves, they become spoon-shaped. The leaf spacing remains rather short and the shoot tips then resemble small heads of cabbage.

Fight boxwood flea

The leaf flea usually does not affect the box tree much and is also eaten by beneficial insects such as spiders, ichneumon wasps or lacewings. It is helpful to remove infected shoot tips. However, there are striking differences between the varieties, because 'Blauer Heinz', 'Elegantissima', 'Angustifolia' and 'Herrenhausen' showed relatively few symptoms, whereas the varieties 'Pyramidalis', 'Green Mound' or 'Graham Blandy' were very strong exhibited.

Scale insects on the box

Especially with ornamental trees you have to deal with scale insects or mealybugs. With the box tree one is particularly often with the comma scale (Lepidosaphes ulmi), which also occurs on fruit trees or rose bushes.

Scale insects: symptoms

The comma scale is about 2 to 3 mm long and colored gray-brown. In contrast to other scale lice species, this species does not form honeydew or soot, but the sucking activities of the comma lice impair the growth of the boxwood. If the infestation is very severe, it will lose its leaves and entire shoots can die off. By shedding the leaves, you can quickly confuse these symptoms with those of boxwood leaf fall, but here you can easily see the lice sitting on the shoots.

Fight scale insects

Since the lice cannot spread very quickly on the boxwood, only individual branches are often affected. These can easily be removed by cutting back. However, if the infestation is very large and pruning is no longer effective, you can use the Treat the plant with oily spray shortly after the lice hatch in May or June. Be careful not to act too late, however, because once the lice's shields harden, they are no longer very susceptible to treatment.

Boxwood gnat on the box

Especially in Central Europe regional (southern Germany and Austria) one has repeatedly with the boxwood gall mosquito (Monarthropalpus flavus) and this little insect can do a lot of damage.

Boxwood gnat: symptoms

Approximately 30 eggs are laid directly in the leaves for each female that dies after oviposition. Small larvae then develop from these eggs and eat burrows in the boxwood leaves. These tunnels, also known as mines, can easily be overlooked at the beginning of the infestation as they only appear as bright spots on the leaves. Later in summer the tissue thickens and light brown spots appear on the upper side of the leaf, which are not very clearly delineated from the healthy tissue. Galls, in which the orange larvae are located, form on the underside of the leaf, and leaf shedding can also occur. Exactly these galls with the larvae in them are a good distinguishing feature to the fungus of the boxwood leaf fall.

Fight the boxwood gnat

Usually the gall midges tend to haunt older plants and this usually does not cause much damage. But pruning can reduce the infestation pressure, and if the infestation is very severe, you can control the larvae with insecticides such as Calipso after they hatch. Here, too, a difference can be seen in the different varieties, since 'Handsworthiensis', 'Angustifolia', 'Herrenhausen', 'Faulkner', 'Rotundifolia' and 'Suffruticosa' are less of the boxwood gnat to be plagued. On the other hand, the variety 'Green Mound' from Canada is particularly heavily infested by this gall mosquito.

A brief summary of important pests on boxwood

• Boxwood moth (Cydalima perspectalis)
• Shoot tip mite (Eriophyes canestrinii)
• Boxwood spider mite (Eurytetranychus buxi)
• Boxwood leaf flea (Psylla buxi)
• Scale insects (Lepidosaphes ulmi)
• Boxwood gnat (Monarthropalpus flavus)

Boxwood damage: frost damage, sunburn, etc.

But not only pests and pathogens can affect your beloved evergreen boxwood. Environmental conditions can also be responsible for damage and the loss of lush green. These are so-called abiotic causes of damage, as they are not caused by living organisms. The following abiotic damage can occur on the boxwood:

• Freezing and frost damage to leaves and roots
• Frost dryness
• Snow break
• sunburn
• Salt damage

How you such Boxwood damage from environmental impact In our special article, you can find out how to recognize and differentiate from pests and what you should do to limit the damage.

Everything you can think of Boxwood diseases should know and how to fight them, we will show you here.