If you have elm trees, be they of the genus Ulmus or they are Zelkova, you may have seen some specimen of Xanthogaleruca luteolathat is to say elm beetle. This is a rather small insect but capable of seriously damaging these trees.
In addition, it multiplies so much and so quickly that the best we can do is take preventive measures against it, since, although it will not dry out, it does weaken it a lot. Let’s see how to avoid it.
What is it?
It is a heat loving beetle of the Chrysomelidae family known as elm beetle or galeruca. It is native to Europe, although today it is also found in North America and Australia.
Before becoming an adult, it goes through different phases:
- Egg: it is yellow in color, and the female puts them in clusters of up to 25 units.
- Larva: It is usually black, sometimes black and yellow, with several rows of dots and on the sides. Measures up to 13mm long.
- Pupa: It is orange-yellow in color with black markings.
- Adult: It is yellow to green in color, with a spot on the head and a wide dark band at the edges. It measures 6 to 8mm long.
What are the damages it produces?
From spring to late summer (if the weather is warm, it can remain active until autumn) it will feed on the leaves, specifically the underside. So what we will see is the leaky foliage.
If the specimen is very young and the pest has spread too much, it could dry out.
What to do to control it?
In Europe the elm beetle has a natural enemy: the wasp Oomyzus gallerucae. Thus, If we are in the Old Continent, the ideal is to do everything possible to attract waspslike planting showy flowering plants and not using chemicals.
Another very important thing, whether we are in Europe or not, is that of buy healthy specimenssince otherwise we would risk infecting those we already have in the garden.
In the event that we want to use a product that can help us repel or eliminate it, I advise the use of diatomaceous earth as soon as spring begins. We mix 35g of this type of soil (actually it is a very fine white powder) with 1l of water, and we spray all the parts of the plant well. You can buy it here!.
They are not very effective, and they are also harmful to the environment. In extreme cases, wrapping the trunk with insecticidal bands could limit the infestation the following year, as it would kill the larvae.
I hope it has been useful to you and you can keep your elms protected .