Defeat The Raspberry Fly

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Defeat The Raspberry Fly
Defeat The Raspberry Fly
Anonim
Defeat the raspberry fly
Defeat the raspberry fly

The raspberry or raspberry fly is a lover of raspberries and blackberries, as well as meadowsweet and meadowsweet. It is easy to determine the fact of her presence by the fading and slightly inclining tops of young shoots. And if you pull slightly for the affected tops, they will surely come off, and on the formed "stumps" circular passages formed by caterpillars will open, in which you can often see pests in person

Meet the pest

The raspberry fly is a gray-colored pest measuring 5, 5 - 7 mm, with small black legs. Its head is characterized by a prominent forehead.

Oval white eggs of the parasite are 0.2 mm long, larvae are 5 mm. Cylindrical, pale white larvae lack legs, and their mouthparts are located inside a pair of anterior segments. The size of brown barrel-shaped false cocoons ranges from 5 to 6 mm.

The larvae overwinter in the surface layer of the earth in false cocoons. When the soil in their places of occurrence warms up to 12-13 degrees (this happens, as a rule, in May), they start pupating. The development of pupae takes on average 7 - 9 days, and the duration of the emergence of raspberry flies is from eight to ten days (in rainy and cold weather, its duration can increase to 15 - 20 days). It should also be mentioned that a huge number of pupae and larvae die from Empusa muscae Cohn - this is the name of the fungal disease that affects them.

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Additional food for raspberry flies is dew, sugar secretions of all kinds of sucking pests, as well as flower nectar. They usually lay eggs one at a time, in the sinuses or on the tops of not yet formed leaves, on the root processes of raspberries, as well as on its young shoots. The total fertility of female raspberry flies is from 60 to 90 eggs. After five to eight days, the revival of the larvae begins - biting into the middle of the young stems, they gnaw out bizarre ring-shaped and spiral passages in them. As a result of such destructive actions, the tops of the shoots damaged by the larvae first droop and wither, and then turn black and eventually completely die off. The feeding of the larvae usually ends in 12-16 days. When the raspberries bloom, the larvae gnaw through small exit holes and go to winter. They hibernate in false cocoons formed especially for this, staying in them until the spring of next year. The annual generation is characteristic of raspberry flies.

How to fight

In fairly substantial amounts, the number of raspberry flies is regularly reduced by various predatory insects, especially ground beetles.

In early spring, as well as with the onset of autumn, under the raspberry bushes, you should thoroughly dig up the soil. Withering shoots at the budding stage of raspberries must be cut out and burned immediately. Also, raspberries need to be thinned periodically, as raspberry flies in thickened plantings feel just great.

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During the summer of May, the parasites need to constantly examine the growing shoots - if damage is found, the tops of the shoots must be cut off (this is done a little lower than the places where the larvae are located) and immediately destroyed. This measure will help to significantly reduce not only the number of pests, but also the number of affected plants. It is not worth worrying about the future fate of the cut off shoots - by the fall, new shoots suitable for fruiting will grow from the buds below.

If there are quite a few raspberry flies on the site, it makes sense to start spraying with insecticides (Agravertin and others). At the same time, one should be aware that chemical treatment on fruiting stems is allowed only in case of urgent need, if, for example, half of the shoots are affected annually. All spraying one or two times must be carried out before flowering, until the height of young shoots does not exceed 15 cm. A product called Actellic is well suited for processing: 15 g of this agent should be diluted in 10 liters of water and start processing plants per 10 square meters - one and a half liters of solution.

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