Appleweb moths produce an army of voracious larvae, well protected by tent-like webs. Without immediate countermeasures, there is a risk of apple trees being damaged. This guide is packed with practical tips for biological control without poison.
How can I combat apple web moths biologically?
To control the apple web moth biologically, you should take immediate measures such as shaking or hosing down infested trees and removing larvae. You can also promote beneficial insects such as parasitic wasps, predatory bugs or caterpillar flies and spray the trees with soap solution in April/May.
Immediate measures – tips & tricks
Biological control measures with immediate effect target the voracious larvae of the apple web moth. The caterpillars are 18 to 25 mm long, yellowish-green, slightly hairy and dotted with black. Legs and head capsule are dark brown to black. In April the feeding feast on the leaves, buds and flowers of the apple tree begins. From mid-May onwards, the characteristic, bright webs emerge, under whose protection the rabble get up to mischief. Take immediate action with these manual control measures:
- Spread the film under the infected apple tree
- Shake small tree vigorously
- Hot down big tree with hard jet of water
- Collect fallen larvae and webs using the foil
Please dispose of the pests in household waste and not in the compost. You can cut out isolated webs from the treetop and throw them in the trash can.
Engage beneficial insects – predators versus apple web moths
When taking emergency manual measures, you can never be sure that you have caught all the pests. We therefore recommend the use of beneficial insects as a second stage of control. A number of predators of the apple web moth are already present in the natural home garden. If necessary, you can increase the population and purchase additional beneficial insects from specialist retailers:
- Parasitic wasps (Ichneumonidae) and chalcid wasps (Chalcidoidea) parasitize the larvae
- Predator bug species hunt the caterpillars
- Caterpillar flies (Tachinidae) lay their eggs in the moth larvae, which then die
It is important to note that many beneficial insects are on the move as specialists. For example, the parasitic wasps of the species Trichogramma cacoeciae parasitize the caterpillars of the codling moth, but disdain the brood of apple web moths. When purchasing beneficial insects, please ask exactly which pests they specialize in.
Retreats with hiding places in the garden ensure that more beneficial insects arrive and the existing population does not migrate. Piles of leaves, green dry stone walls, wild fruit hedges and a rustic Benje hedge invite the useful insects to linger so that they can hunt the caterpillars of the apple web moth.
Tip
In the period from the beginning/mid-April to mid-May, apple web moth larvae devote themselves almost unprotected to the leaves and flowers in the apple tree. During this phase, spray the crown repeatedly with soap solution (€38.00 on Amazon), the proven biological control agent. You can make the home remedy yourself or buy it ready-made. As a positive side effect, you can use soap solution to combat other pests at the same time, such as aphids, spider mites or scale insects.