In addition to the usual suspects among woody pests, 2 species of insects have specialized in willows. Find out here what pests we are talking about and how to recognize and combat them.
Which pests attack the corkscrew willow and how do you combat them?
Pests on the corkscrew willow are usually willow borers or willow leaf beetles. Willow borer caterpillars bore into wood, while willow leaf beetles eat the leaves. Control is carried out by collection, insecticides or biological agents such as soft soap solutions.
Willow borer – moth with voracious brood
Across Europe, the willow borer primarily targets willows in order to lay its eggs under the bark in June and July. The pests are recognizable as gray-brown moths with a wingspan of 6-10 cm. The reddish caterpillars grow up to 7 cm long and bore through the wood. Feces and the red-colored nail fall out of the oval feeding ducts. The caterpillars go on their feeding sprees for up to 4 years, which even the robust corkscrew willow cannot survive unscathed. The butterflies themselves do not eat.
Effective control agents are not yet available. In the early infestation stage, the butterflies and caterpillars should be collected. Since the larvae penetrate deep into the heartwood, it takes a lot of luck to catch all the pests. In order to prevent further spread in the garden, in the worst case scenario you cannot avoid the complete removal.
Willow leaf beetle eats the bushes bare
They are tiny at 6-9 mm and yet have a great appetite for the leaves of a corkscrew willow. Willow leaf beetles are easy to identify by their 20 black spots on the yellow-white wing coverts. Where they occur in large numbers, young willows are at great risk to their lives because the trees cannot recover from damage even in the ideal location. To combat this, proceed as follows:
- Collect the cold-stiff beetles early in the morning
- Use an approved insecticide under high infestation pressure
Various products are available for use in the home garden that will put an end to willow leaf beetles. The tried and tested products include pest-free Calypso from Bayer Garten (€24.00 on Amazon) and Naturen Bio pest-free with rapeseed oil.
Tip
If aphids dare to attack the shapely leaves of your corkscrew willow, you can save yourself the trouble of resorting to chemical insecticide. In practice, the soft soap solution has proven to be very effective as a biological control agent. Add 1 tablespoon of pure soft or curd soap with 1 splash of spirit to 1 liter of water. Sprayed on the leaves every 2 days, the plague quickly ends.
