Various lice like to spread around the garden and hardly miss any plants. Which species of louse targets the Douglas fir? However, this immigrant tree species is also plagued by other tiny pests. What are they and how do you track them down?
Which pests attack the Douglas fir?
The most common pests of Douglas fir are Douglas fir mealybugs and bark beetles. Mealybugs suck on the needles, causing discoloration and needle loss, while bark beetles attack weakened trees and overwinter under the bark.
The most common pests
In the first phase of life, around 15 years, Douglas firs are more susceptible to diseases and are more often attacked by pests than older specimens. The biggest pests include:
- Douglas Mealybugs
- bark beetle
The Douglas fir mealybugs followed the Douglas fir, which came to us from North America about 200 years ago, across the Great Pond and are now spreading rapidly here too. The Douglas fir sawfly is another immigrant pest.
The role of winter frost damage and fungal diseases
The Douglas fir is less susceptible to pests, but if it is weakened by frost damage or fungal diseases, the likelihood of an infestation increases. Both of these together can have a devastating effect on the he alth of the tree and even cause it to die completely.
Douglas Mealybugs
The Douglas fir mealybug likes to suck on the needles of this tree species, the consequences will soon become clearly visible:
- Needles curve
- first discolorations become visible
- Eventually needle loss occurs
If the tree also suffers from Sooty Douglas Fir, the loss of needles can be so severe that it can no longer recover.
Tip
You can easily recognize a mealybug infestation if you take a closer look at the needles of the Douglas fir. These pests leave white, powdery spots on them.
Control measures
Mealybugs are usually controlled with approved pesticides. The home remedies often used in the home garden have little effect and are difficult to use in practice on large trees.
To prevent pest infestation in advance, you should strengthen your young trees. Nettle manure and horsetail broth are two natural tonics that anyone can easily make themselves.
bark beetle
More and more native pests are discovering the Douglas fir, including bark beetles. Especially when the tree is weakened by a fungal disease or unfavorable living conditions, these types of beetles like to attack it.
- Pest hibernates under the bark
- The first beetles will be spotted from mid-April
- spread out in the upper part of the crown
- Dead, reddish-colored needles are the result
Infested trees should be felled as quickly as possible, otherwise the pest can spread to other trees.
