Various lice like to spread in the garden and hardly miss a single plant. Which louse species is after the Douglas fir? This immigrated tree species is also plagued by other tiny pests. What are they and how do you track them down?

Brown needles can indicate a pest infestation

The most common pests

In the first phase of life, around 15 years, Douglas firs are more susceptible to disease and are more frequently attacked by pests than older specimens. The biggest pests include:

  • Douglas Fir Mealybugs
  • bark beetle

The Douglas fir mealybugs followed the Douglas fir, which came to us from North America about 200 years ago, across the pond and are now also spreading rapidly in this country. The Douglas-fir seed wasp is another invasive pest.

The role of winter frost damage and fungal diseases

The Douglas fir is not very susceptible to pests, but if it is weakened by frost damage or fungal diseases, the probability of an infestation increases. Both together can have a devastating effect on the health of the tree and even cause it to die completely.

Douglas Fir Mealybugs

The Douglas fir cotton aphid likes to suck on the needles of this tree species, the consequences are soon clearly visible:

  • Needles bend
  • first discolorations are visible
  • Eventually needle loss occurs

If the tree also suffers from sooty Douglas fir shedding, the loss of needles can be so severe that it can no longer recover.

tips

You can easily spot an infestation with mealybugs if you take a closer look at the needles of the Douglas fir. These pests leave white, powdery patches on it.

countermeasures

Mealybugs are usually controlled with approved pesticides. The home remedies often used in the home garden have little effect and are also difficult to use in practice with large trees.

In order 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 at home.

bark beetle

More and more native pests are discovering the Douglas fir, including the bark beetle. Especially when the tree is weakened by a fungal disease or unfavorable living conditions, these beetle species like to attack it.

  • Pest hibernates under the bark
  • from mid-April the first beetles will be sighted
  • spread in the upper part of the crown
  • dead, reddish discolored needles are the result

Infested trees should be felled as soon as possible, otherwise the pest can spread to other trees.

Category:

Trees