The cherry vinegar fly can not only attack wine. Here you can find out how to recognize the small fruit flies and how to prevent and combat an infestation.
contents
- Symptoms: How to recognize a spotted-wing drosophila infestation
- A brief profile of the cherry vinegar fly
- Cherry spotted fly: preventive measures
- Combat cherry vinegar fly
Symptoms: How to recognize a spotted-wing drosophila infestation
The spotted-wing drosophila affects all types of soft fruit, including grapes, cherries and blackberries. Given the choice, the fly clearly prefers raspberries and blueberries. In contrast to most native representatives of the vinegar fly, the cherry vinegar fly also infests healthy fruit and is therefore a dangerous pest. Symptoms caused by the spotted-wing drosophila can often only be seen when a larva has already hatched from the egg laid in the fruit. When the larva has eaten its fill, the fruit collapses and becomes mushy. The holes in which the spotted-wing drosophila lays its eggs are difficult to see with the naked eye. And who would want to eat a berry with larvae as a side dish?
A brief profile of the cherry vinegar fly
The spotted drosophila (Drosophila suzukii) originally comes from Asia and was introduced to Europe in 2008. Since then, it has been spreading more and more northward from year to year. In southern countries such as Italy, the fly is already causing massive problems in fruit growing and is responsible for severe crop failures and even total loss. The great resemblance to the native fruit flies makes identification almost impossible for the hobby gardener.
With a size of only 2 - 3 mm, it can still cover several kilometers. In relation to the body size of the small fly, this is an extremely long distance. However, their long-distance flight abilities are not quite sufficient, which is why the most common form of distribution is still the export of infested fruit. One warm season is enough for 15 new generations to emerge from one spotted wing drosophila. Their major weakness is their sensitivity to cold temperatures. The flies already die when the temperature is slightly below zero. However, they also survive the winter in ventilation slits and other hiding places in heated buildings.
Cherry spotted fly: preventive measures
Since probably nobody wants to eat maggot fruit, preventive measures are of crucial importance. As the end consumer, we have little influence on the further spread of the spotted drosophila. With a few tricks, however, the drosophila can still be kept away from the berries in your own garden. The most complex and at the same time most effective method is netting the fruit trees and shrubs. Since the flies almost exclusively attack ripe fruit, the net must be attached while the fruit is still green. The whole thing only works with a maximum mesh size of 0.8 mm.
Another method is to build a trap. Simply take a transparent PET bottle and rinse it well. Then poke about ten 3 - 4 mm holes in the upper area. You can use a metal needle for this, for example, which is best heated over a tea light. After that, the bottle is filled with attractants. Vinegar and red wine are particularly good for this. A splash of dishwashing liquid is also a must, otherwise the flies won't go under and may be able to leave the trap again. The bottle is now hung at the level of the fruit and will probably quickly fill with fruit flies (because even the native fruit flies cannot resist this scent). The success with this trapping method increases with the number of traps.
If you already have infected plants, then all infected fruit must be destroyed. The fruits must not simply be put on the compost, because from there the flies can spread again. To be on the safe side, you should put the affected fruit in a plastic bag that is as transparent as possible and place it in the blazing sun for several days. The larvae are killed by the heat and the fruits can then be put on the compost.
Combat cherry vinegar fly
It is not possible to combat the spotted-wing drosophila directly after the fruit has been infested. This is because the fruit is infested when ripe and spraying just before the fruit is eaten would be irresponsible. The active ingredients in the spray do not have enough time to break down!