As with most native trees, there are also pests that afflict the birch. In addition to the fairly frequent fungal infestation, to which birch plants are relatively susceptible, various creatures feast on the trees. You can find out here which of these do not cause any damage and when you should intervene.
Aphids also like to eat birch trees
Pests in the birch - these are the most common
Birch trees can be affected by a wide variety of parasites. In German-speaking countries, it is mostly the following species.
birch leaf roller
True to its name, birch leaf roller causes curled leaves. These only hang brown and dead on the birches and some other tree species. It is a beetle three to five millimeters in size with a punctured elytra.
Usually there is not much damage. You can prevent the disturbing sight by removing an affected leaf of the birch as soon as possible. Detaching the leaf coils will reduce infestations next year.
Big birch sawfly
The caterpillars of the birch sawfly, which are around 25 millimeters in size, cause a lot of feeding on the edges of the leaves. This can go as far as completely bare trees. In general, however, the damage is limited and requires no countermeasures. It may be advisable to remove leaves heavily covered with caterpillars.
thrips
Silvery speckled leaves are usually an indication that so-called thrips or thrips have attached themselves to the birch. However, unless the invasion is life-threatening on a large scale, you do not need to intervene. If necessary, the tree regulates the problem itself by shedding affected leaves prematurely.
Various types of aphids
What is recommended for thrips also applies to aphids: observe the tree and only use pesticides to help with a severe infestation. Lavender placed near the tree may help.
birch bug
If your birch is inhabited by small brown animals with black dots that are about five millimeters in size, they are probably birch bugs. They make themselves noticeable through their pronounced feeding behavior, but do not fundamentally harm the tree.
Rather, they become a nuisance to the garden owner, because the bugs multiply extremely quickly and like to get straight into the house from the birch tree in the garden. There they chirp annoyingly and cause an acrid smell. The only thing that helps here is prevention, preferably with fine-meshed window nets. Pests that have already arrived in the house can be sprayed with lavender water and then carefully swept away.