Nothing is more annoying than biting into a sun-ripened cherry and finding a maggot. The culprit is the cherry fruit fly, a small pest with a very precise timetable. And that very timetable is the key to outwitting it.
Because the fly is on the wing only in a certain window in early summer. Know that, and you choose your variety so the harvest comes before it, and you pick maggot-free cherries while your neighbour is sorting. Let us look at how.
What sits inside the cherry
The cherry fruit fly lays its eggs specifically in cherries that are turning from greenish yellow to reddish. From each egg hatches a tiny maggot that feeds into the flesh around the stone. After a few weeks it drops to the ground, pupates there and overwinters as a pupa in the soil. The next early summer the new generation of flies hatches.
This cycle reveals the two points of attack: the window of the flight and the soil under the tree. Protection targets both.
How to keep your cherries maggot-free
Plant an early variety
Early sweet cherries ripen and are picked before the fly reaches its peak. They are the most effective and simplest protection of all.
Hang up yellow traps
From the moment the fruit changes colour, hang yellow sticky traps in the tree. They show you when the fly is active and catch some of the females.
Net small trees
Over low trees, spindles and container cherries, lay a fine-mesh net as soon as the fruit changes colour. Then the fly cannot even reach the cherries.
Remove maggoty and fallen fruit
Consistently gather up affected and fallen cherries and dispose of them. Every maggoty fruit left lying supplies the next generation.
Keep an eye on the soil
Because the larvae pupate in the soil, it helps to keep the area under the tree clean. Some lay out a fleece during the larval drop or let chickens forage under the tree.
The cherry fruit fly, by the way, has a relative it is often confused with, but which works quite differently.
The fly flies by the clock. Pick early and you are done before it even starts.
The core rule against the cherry maggot
Frequently asked questions
How do I recognise a maggot infestation?
Affected cherries are often soft, dented and slightly discoloured at the puncture spot. Cut one open and you find the white maggot around the stone. The flies on the yellow traps are another sure sign.
Why do early varieties stay maggot-free?
Because they ripen and are picked before the cherry fruit fly reaches its flight peak. The fly then finds no more colouring fruit for its egg-laying. Late varieties, by contrast, are fully affected.
Do yellow traps really help?
For monitoring, certainly, they show you the start of the flight precisely. For control they alone are often not enough in heavy infestation, but they are a good component alongside an early variety and a net.
What do I do with the maggoty cherries?
Gather them up consistently, including the windfalls, and dispose of them in the residual waste or buried deep, not on the open compost. That breaks the cycle, since otherwise the larvae pupate in the soil.
Is this the same as the spotted-wing drosophila?
No. The spotted-wing drosophila (Drosophila suzukii) also attacks fully ripe and other soft fruit and cannot be dodged through the choice of variety. It is a separate, more difficult subject.
