A he althy spruce is quite decorative and an eye-catcher in your garden. However, if the tree becomes sick or suffers from pests, then it looks completely different and soon becomes unattractive.
Which pests attack spruce trees and how do I recognize an infestation?
Spruce trees can be attacked by bark beetles, spruce gall lice and Sitka spruce lice. Bark beetle infestation manifests itself through drilling dust and drill holes, spruce gall lice leave small galls, and Sitka spruce lice can be detected by a tap test.
What pests attack spruce trees?
Spruce trees have very special enemies: bark beetles, spruce gall louse and Sitka spruce louse. An infestation should always be taken very seriously, as the neighboring trees are quickly affected. In addition, the chance of saving your spruce only exists at the beginning of an infestation.
Possible pests of spruce trees:
- Bark beetles, especially book printers and engravers
- Spruce gall louse
- Sitka spruce louse or tube spruce louse
How do I recognize a pest infestation?
You can detect an infestation with the Sitka spruce louse, also known as the tube spruce louse, with the so-called tap test. Hold a white cloth under a branch and tap it. The lice, if present, will then fall onto the cloth in a clearly visible manner. Now you should act quickly, otherwise your spruce will die.
You will rarely see bark beetles on your spruce, but you will probably see the traces of these voracious animals. The first signs are small brown piles of dust at the base of the tree, the so-called drill dust. If you then take a closer look at the spruce, you may also notice the drill holes. However, these are usually located in the upper area of the crown.
You can easily recognize the spruce gall louse by the small galls that the louse deposits on the spruce. They are only about five millimeters in size and are reminiscent of a pineapple. If the needles of the spruce turn brown or fall off, then it is almost too late for help.
What can I do against pests?
If there is a severe infestation with the Sitka spruce louse or the bark beetle, there is usually nothing you can do to save the tree. It should be felled so that the pests cannot spread to other trees. The same applies to bark beetle infestations. Sprays containing paraffin oil help against the spruce gall louse.
Tip
In natural gardens, spruce gall lice are decimated by beneficial insects such as ladybirds and parasitic wasps.
