Raspberry stem fly (sometimes called raspberry fly or raspberry stem fly) is a dangerous pest that can deprive you of the main part of the crop, and if you do not take any measures, then the whole crop. Noticed the wilting of young raspberry shoots? Why do young shoots of raspberry wilt in spring, how to treat? How to deal with raspberry stem fly, what to do? What you need to know about her? Raspberry stem fly (Chortophila dentiens) winter in the upper layers of the soil under raspberry bushes. Its flight coincides with the growth time of young shoots. In the Kuban it is about mid-April. In central Russia - in mid-May.
How to deal with raspberry fly in spring? It was at this time that she crawled out of the ground and was ready for the reproduction of offspring. Raspberry fly lays one egg in each sinus of the top of raspberry leaves. A larva grows from an egg. It does the most harm - making spiral-shaped passages in the stem from the top down. The top of the damaged shoot first withers, stops growing, then turns black and rots.
How to process raspberries from raspberry flies? Knowing the timing of the departure of the pest, you can process the young tops, for example, with Iskra or Actellik. But the chemical method is recommended to be used only if raspberry flies damage more than 50% of the plantings. Still, chemistry is not very good. It will destroy pests, but we will also get ...
A good way to get rid of the larvae that settled for the winter, digging in the autumn of soil around raspberry bushes.
In the picture below, a raspberry shoot may be damaged by a stem fly. So far it is only visible that he has stopped growing. The growth point does not develop, which means the introduction of a fly into an escape has occurred. The pest has not yet damaged the stem - wilting, blackening of the leaves in front. If you did not manage to scare off a raspberry fly in time, then there is only one way out - pruning of damaged branches.
The larva of the fly, if the branch is not cut in time, can reach the base of the shoot. In this case, he can no longer be saved, he will dry up. As soon as the raspberries begin to bloom, the pest, having reached the base of the shoot, moves to the soil. There pupates and the process repeats: a fly - eggs - larvae.
If we allow the development of this process from beginning to end, then the gardener has no choice but to cut the damaged branches to the ground. But it can and should be done differently.
Why do raspberries drop their heads, wither? There is a second way to deal with raspberry flies.
As soon as you notice that the green top of the shoot begins to fade and the ends of the leaves turn black, cut off about half of the branch. The cut parts of the branches should be burned immediately, the larvae remained there. You can not give them the opportunity to survive, so you can not be late with pruning.
By the way, you will probably notice that a flying pest lays eggs in the tops of the most powerful shoots. These branches do not need to be cut to the ground, because the main crop is formed on them. In addition, near them strong side shoots of substitution begin to grow from the ground.
Trim strong damaged branches to half only if you are not late. To the bottom, to the roots, cut only weak shoots.
Cutting out all damaged branches as close to the ground as possible (first method), you will deprive yourself of the main part of the crop. And if you allow the propagation of raspberry stem flies, then the whole crop. But the second method, on the contrary, saves and even increases the yield of berries due to incomplete pruning.
We have listed the main methods of dealing with raspberry flies. Now it's up to you. Have a good harvest!