A caterpillar infestation of the apple tree can cause considerable damage: The animals not only eat the leaves, the flowers and fruits can also be affected. With our tips you can successfully combat and prevent an infestation.
Which green caterpillars attack the apple tree?
These are thecaterpillarsof theSmall Frostmoth(Operophtera brumata), abutterflyfrom the peeping tom family. These are light green in color and have whitish-yellow stripes. Since they only have two pairs of feet, they move with a typical cat hump.
How do the green caterpillars get into the apple tree?
Thefemalesof the frost mothlaytheireggs,from which the green caterpillars hatch, in thebark cracksandshoot tips of the apple tree. To do this, they crawl up the trunk at the start of the first night frosts. Only the male frost moths have functional wings and swarm out at dusk to fertilize the females on their way to the crown.
During the cold season, the eggs are in a resting phase. The caterpillars hatch as soon as the flower buds open until May.
What damage do the green caterpillars cause?
Since thecaterpillarsoccur in verynumerous, thefeeding damageof the small frost mothconsiderable. They first eat the buds and later also the apple leaves. Although the apple tree does not die as a result of the frostbite infestation, the loss of leaves weakens the fruit tree. This can even affect next year's earnings.
What to do about the green caterpillars in the apple tree?
Even if the frost moth has already settled in your apple tree, you don't have to put up with a tree that has been eaten bare, because there arevarious control options:
- Certain parasitic wasps lay their eggs in the eggs of the frost moth and thereby prevent further caterpillars from hatching.
- Predators such as birds significantly minimize the number of larvae. Ensure their settlement by providing nesting sites.
- The bacterium Bacillus thuringienisis is fatal to the green caterpillars. The treatment is possible from a temperature of 15 degrees.
How can I prevent green caterpillars in the apple tree?
Frost moth can be prevented very wellby using glue rings. You should attach the rings, coated with anon-toxic glue, to the trunk of the apple tree by the end of September at the latest. They prevent the females from crawling up the tree and laying their eggs.
So that the female butterflies do not crawl under the glue rings, you should stuff larger bark depressions. Also equip the tree posts with glue traps so that the insects cannot use them as a bridge into the treetop. Remove the glue rings again in December.
Tip
Caterpillar glue as an alternative to glue rings
For apple trees with very rough bark, you can apply special caterpillar glue directly to the trunk using a brush. This will be carefully removed in January with a spatula and replaced if necessary.
