You bite into the finest apple and find the brown tunnel, perhaps even the grub: the codling moth is the classic among apple nuisances. Almost every home garden knows it, and many reach helplessly for the spray, although that hardly helps and is not needed in the home garden.
Because the codling moth can be kept well in check with simple, poison-free means. The key is to understand its life cycle and intervene at several points at once. This article shows you how to bite into clean apples again.
Who is the codling moth?
The codling moth is a small, grey-brown night moth. It is not the moth itself that harms but its larvae. The moth flies in warm dusk hours from May and lays its eggs on young fruit and leaves. From the eggs the caterpillars hatch, bore into the fruit and eat their way to the core.
After a few weeks the larva leaves the apple again to pupate, usually in bark crevices on the trunk. In warm summers a second generation follows, causing a second wave of maggoty fruit in late summer. This very cycle is the point of attack.
The three poison-free pillars
How to contain the codling moth
- Pheromone trap for monitoring
A pheromone trap lures the males and shows you when the flight begins. It does not control the moth directly but reveals the right moment for the other measures.
- Trap belt on the trunk
A belt of corrugated cardboard around the trunk offers the wandering larvae a shelter to pupate. You take it off regularly and destroy the larvae sitting in it.
- Gather windfall
Fallen, maggoty apples often still hold the larva. Gather windfall regularly and use or dispose of it promptly, before the larva wanders off.
- Encourage beneficials
Tits, earwigs and parasitic wasps eat eggs and larvae. Nest boxes, deadwood and diverse planting bring these helpers into the garden.
Timing is everything
The most common mistake is to do something only once. The codling moth flies over weeks, and in warm years a second generation comes. So hang the pheromone trap as early as May and watch the flight. Fit the trap belt in early summer and check it regularly. And gather the windfall consistently over the whole season.
For heavier infestations there are additionally biological products based on the granulosis virus, which targets the larvae and spares beneficials. On small trees a fine-mesh net also keeps the moth off the fruit.
Do not spray, break the cycle: a trap to monitor, a belt on the trunk, windfall away. And stay on it all season, because of the second generation.
The core rule on the codling moth
Frequently asked questions
What is the worm in the apple?
It is the larva of the codling moth, a small night moth, not the maggot of a fly. It bores into the young fruit and eats its way to the core, which makes the apple maggoty.
How do I control the codling moth without poison?
With a combination: pheromone traps show the flight, corrugated-cardboard trap belts catch the pupation-ready larvae, and regularly gathered windfall breaks the cycle. Beneficials and, on small trees, nets help too.
What is the pheromone trap for?
Mainly for monitoring. It lures the males and shows when the flight begins. That way you hit the right moment for trap belts and other measures. As the sole control it is usually not enough.
Why do I have worms again in late summer despite control?
Because in warm years a second generation flies. Slack off after the first wave and you get the next in late summer. Stay consistent with windfall and trap belt all season.
Should I leave the windfall for hedgehogs and birds?
Not with the codling moth. Maggoty windfall often still holds the larva, which wanders off and pupates. Gather infested windfall promptly. Healthy fruit you may happily leave for animals.
