The vine weevil is a dreaded garden pest that likes to attack the leaves and shoots of hardy foliage plants, developing a sizeable appetite in the process. However, it is not this feeding damage that massively weakens the laurel cherry. The larvae of the beetle, which attack the root system, damage the plant so badly that it can even die.
Vine weevil larvae can cause a lot of damage
The Pest
In our gardens, the ridged vine weevil and the large brown weevil are the most common. Both species are dark in color, nocturnal and reach a size of about one centimeter. The beetle prefers areas with humus-rich soil where the white-colored larvae find optimal living conditions. They develop underground and feed on the roots of host plants, which they can inflict considerable damage on.
The bad image
Plants affected by the vine weevil show a typical pattern of damage, which is referred to as pit damage. The leaves are eroded in a semicircle, but show no pitting. The larvae living in the soil first feed on the fine root hairs of the laurel cherry. From there they eat their way to the main root and gnaw all subterranean parts of the plant.
Discover the beetle
The vine weevil is nocturnal. In order to track down the beetles, it is advisable to search the laurel cherry for the pests with a flashlight after dark.
Fight the voracious beetle
If you have spotted the little crawlers, you should set up vessels filled with wood wool under the laurel cherry. This is where the vine weevils will hole up during the day so you can destroy them. Check the traps daily to stop the pests from multiplying.
It is more effective to fight the larvae. The optimal time for this is April and May as well as August and September, when the larvae have just hatched in large numbers. Specialist shops stock parasitic nematodes that kill the offspring of the weevil in a few days without harming humans or animals. The effect of this environmentally friendly method is very lasting, as the nematodes continue to multiply in the bodies of the dead vine weevil larvae.
Nematodes - natural helpers in the fight against the vine weevil
You should spread 500,000 nematodes per square meter, which you can get from retailers in tightly sealed plastic bags with carrier powder. Before releasing the beneficial insects, water the soil thoroughly so that the nematodes find enough moisture to be able to reach the larvae. The animals work most effectively at soil temperatures between 15 and 25 degrees. Since they are sensitive to UV light, application in the evening hours or when the sky is cloudy is recommended.
tips and tricks
Neempress cakes spoil the appetite of the voracious bugs. These are worked flat into the ground around the cherry laurel. The neem oil it contains is absorbed by the shrubs and is toxic to both beetles and vine weevil larvae.