While the Nordmann fir spoils our eyes with its lush green needles, various species of louse are after their inner values. They suck the plant sap without any measure and thus weaken their “breadwinner”. This has to be stopped soon.
Which types of louse attack Nordmann firs and how do you fight them?
Fir shoot lice, pine trunk lice and mealybugs are the main species found on Nordmann firs. Pine shoot aphids can be controlled by repeated chemical sprays. Pine trunk lice usually cause less damage, but if there are several pests infested, control is advisable. Mealybugs can be removed by hand or with soapy water.
Lice species on the Nordmann fir tree
The following types of louse can mainly be seen on the Nordmann fir:
- Fir shoot lice
- Pine trunk lice
- Mealybugs
Pine shoot aphid
The fir aphid was introduced from the Caucasus, a region from which the Nordmann fir originally comes. Young trees and specimens weakened by the bark beetle are primarily susceptible. A warm location, for example on a southern slope, can also promote an infestation.
Around May, the lice larvae hatch and immediately begin to suck the sap of the Nordmann fir. They are about 0.5 mm in size and black. Three white dorsal stripes are added later. The fir shows stunted shoot and branch tips. If the infestation repeats for several years, the fir tree can die.
The fight is carried out with chemical sprays, which have to be repeated several times. Control over the course of the year is also necessary so that all life stages of this louse species are recorded.
Pine trunk louse
White wax flakes on the bark are a typical indication of an infestation. These are the characteristics of the pest:
- adult lice are black-red in color
- they have a length of approx. 1 mm
- the body is spherical and covered with white wax threads
- Larvae are orange-red, with black eyes
- the eggs are also orange
As the transport of water and nutrients is impaired, individual branches can die and the fir tree can lose needles. However, the damage caused by the fir tree louse is limited and cannot pose a threat to the Nordmann fir.
Tip
Fir trunk lice are not always the only pests on the Nordmann fir. If pine shoot aphids or pine bark beetles are also at work at the same time, control is absolutely necessary. Because together you can cause serious damage.
Mealybugs
The infestation can also be discovered with the naked eye based on the traces left by the mealybugs. It is the woolly covering whose white color contrasts with the green of the needles. If the infestation is weak, only small spots will appear, while a more severe infestation can cover the entire fir tree. The longer and the more numerous the lice suck plant sap, the more they weaken the fir tree.
Wolflice can still be collected by hand from small Nordmann firs, but no specimens should be overlooked. Larger fir trees can be sprayed with soapy water (€9.00 on Amazon).
