The Content Of The Article:
- General information
- Chemical sprays
- Biological pesticides
- yellow panels
- network coverage
- ground cover
- Avoidance by variety selection
An infestation of the native cherry trees with cherry fruit flies can develop into a real plague and make the cherry harvest completely inedible. To protect the delicious fruits from the voracious maggots of flies, in most cases a mixture of different methods of defense is necessary. These countermeasures include both the funds raised and the provision and selection of a more resistant variety.
General informationThe cherry fruit fly is a dreaded pest that reproduces with the help of cherries. At the end of spring, the fly deliberately seeks cherry trees to feed on the fruits and lay their eggs there. Especially in sunshine, the cherry fruit flies suck the food and host plant to prepare for the reproduction. The then hatching larvae often eat themselves completely through to the cherry stone and destroy the whole fruit. After laying the eggs and training the larvae, the cherries start to rot and then fall to the ground. Above all, late ripening varieties are affected, as the flies do not start breeding until the beginning of the summer. Especially in very dry years with warm temperatures and few rainfall, this pest can develop into an extreme plague.
- Prefers sour cherries, snow berries, bird cherries and bird cherries
- Cherry fruit fly is between 3.5-5 mm in size
- Slip out of the dolls in the ground in spring
- Flight time is between mid-May to early July
- Eats about 10 days from the nectar of cherries
- Afterwards, up to 200 eggs are deposited
- Lay eggs only in yellow to light red fruits
- After 5-12 days the maggots hatch
- Leave the fruits after about 3-4 weeks
The cherry fruit fly has the botanical name Rhagoletis cerasi and is widespread in Europe as well as in Asia. It has some similarities to the traditional housefly, but looking closely, you can quickly make out the differences. Due to the characteristic externalities, the pest in the garden can be easily recognized. If the flies are found in large quantities, then these are either on the approach or it has already come to an infestation. Affected fruits will change only after some time, so the cherry trees should always be under observation and the fruits are regularly examined for changes. Only in this way can appropriate countermeasures be taken in time to prevent the spreading of a pest and to save the rest of the harvest.
- Fly is characterized by wings with brownish bands in transverse form
- Characteristic are green compound eyes
- Forms trapezoidal and yellow spine shield, which is extremely noticeable
- Affection shows up in the stalk area by brownish discolored areas
- Pulp softens around the kernel and begins to rot
- Inside the fruit are one or more maggots
- Maggots are white and grow up to 6 mm long
- Mostly stay close to the core
- When tearing the fruit, maggots are clearly visible
- Flies can deposit up to 80 eggs in a single fruit
- Single fly can attack more than one kilogram of cherries
Chemical spraysMost chemical remedies for the cherry fruit fly are no longer allowed in Germany. However, there are still a few resources that are not allowed in local gardens.
- Mospilan SG can only be used for professional fruit growing
- May only be used by competent persons
- Chemical agent has no approval for the use of house and allotment
Biological pesticidesFor private use, there are biological sprays against the cherry fruit fly, which can be bought in stores and on the Internet. As an antagonist of the cherry fruit fly are especially mushrooms, which attack the insects and thus render harmless. These are biodegradable and safe for humans. However, the fungal spores are relatively quickly inactivated by the UV rays, so the treatment must be performed several times. In this way, later hatching flies are destroyed.
- Use plant protection products based on fungi
- The fungus Beauveria bassiana has proven itself
- Necessary are multiple treatments to achieve high efficiency
- First treatment about a week after the start of the flight
- Important is sufficient application on well cut trees
- Full wetting of the entire treetop is required
- Repeat every week until a few days before the harvest
At the time of filing, the cherry fruits are still yellow and just ripen, so the cherry fruit flies are fixed on their yellow color scheme.Yellow sheets are a biological control measure against the cherry fruit fly and are suitable for catching the pests. These attract the flies to start the yellowing of the fruits and keep them from the cherries. However, the yellow glue boards must be installed in sufficient quantity already at the beginning of the flight, otherwise it may already have come to an infestation. Since even a single fly can lay up to 200 eggs, this method is very useful to protect the cherries. However, the panels should only be used from the beginning of the flight to the end of the harvest, as they also attract and kill other and often useful insects.
- Depending on the tree size, attach 2-10 panels
- Use at least two traps per meter of tree height
- Attach to the southern and western side of the tree
- Ideally install outside on the crown
- Flies are attracted by the yellow color
- Stick to the glued surface
- Method captures a large part of the flies
- Oviposition is thus prevented in the long term
network coverageA holistic measure against infestation with cherry fruit flies is the protection of fruits with the help of a net. However, this method is somewhat difficult with old trees. If the trees exceed the height of a house and have formed extremely bulging branches, then it is a difficult task to surround the entire treetop with a network and protect. When buying the nets, it is important to pay attention to the correct dimensions of the mesh. If the holes in the net are too big, then the cherry fruit flies can easily slip through the mesh and still lay their eggs in the cherries. In addition, the nets also provide good protection against other pests and gluttonous birds.
Tip: Nets are ideal for smaller trees.
- Also useful for sections of the cherry tree
- For very large trees protect only parts with many fruits
- Close-meshed networks are available in DIY stores and garden centers
- Meshes should not be too wide
- Mesh size should be between 0.8-1.2 mm
The cherry fruit flies hatch from mid-May from the dolls, which have wintered in the soil at a depth of about 3 cm. This time depends on the weather and therefore may differ from year to year. When the ground is covered, the hatching of adult flies from the ground can be temporarily suppressed. Furthermore, can be prevented by a ground cover the burial of maggots in the ground from the outset. The maggots can either fall from the eaten cherries on the ground or fall together with the rotten cherries from the tree down. Afterwards, the maggots crawl in the ground. If this contact with ground is interrupted, then do not hatch any new cherry fruit flies by the next spring end.
- Cover the floor with nets before hatching
- Dig in the edges of the net deeper for a firm grip
- Flies are trapped under the net until harvest
- Necessary mesh size 0.8-1.2 mm
- Lay tarp or fleece on the floor under the cherry tree
- All falling cherries and maggots land on a laid surface
- Then daily sweep the fallen down and collect
- Give maggots and fallen fruit in transparent and tightly closed trash bags
- Leave pouch in blazing sun
- All the maggots die from the resulting heat
- Dispose of contents of the bag after a few days on the compost
preventionCertain precautionary measures can be taken so that neither the cherry fruit fly nor its maggots can spread. In addition, no wild and hedge cherries should grow near cherry trees intended for harvest, as these increase the transmission risk. Certain species of birds that hunt insects as prey in flight can significantly reduce the number of adult cherry fruit flies. In addition, even with nematodes a good efficiency in the fight can be achieved. The parasitic nematodes penetrate through the skin into the larvae and kill them in the soil.
- Poultry farming in the garden reduces the infestation
- Chickens pick down fallen maggots and hatching dolls from the ground
- Provide breeding grounds for swifts and swallows
- Natural predators are also ground beetles, parasitic wasps and spiders
- Grown under the cherry tree very late mow, so the soil stays cool longer
- This delays the hatching of the flies
- In early June, nematodes of the genus Steinernema settle
- Fill the watering can with warm and stale tap water and the nematodes
- Immediately bring them out under the infested trees
Avoidance by variety selection
In order to prevent infestation from the beginning, the right choice of variety is crucial.If the cherry tree bears fruit very early in the year, the fruits turn yellow at a time when the cherry fruit flies have not yet pupated.
- Affected by infestation are especially late ripening varieties
- Early ripening varieties are usually significantly less infested
- Among the early varieties include Burlat, Earlise and Lapins
- Also yellow-fruiting varieties are less susceptible, z. B. donkey yellow