Blackberries are not the most popular berry in Russia, they are not grown here on an industrial scale, as, for example, in the USA. But more and more often Russian summer residents pay attention to this plant, preferring it to all the familiar raspberries. These types of berries belong to the same family - Rosaceae. But, unlike her relative, blackberries have great resistance to diseases and pests... However, this does not mean that the berry does not require care and protection from insects at all. In this article we will consider what pests you can find on blackberries, in particular flies, the reasons for their occurrence and how to deal with them.
Why do insect pests appear on blackberries?
Blackberries can be attacked by pests for the following reasons:
- The line between the species differences of blackberries and raspberries is becoming increasingly blurred. Many modern high quality blackberry varieties in their genotype have a raspberry gene, and these two varieties are often grown in the neighborhood. All this leads to the gradual loss of the berry of its natural resistance to diseases and pests.
- Besides raspberries, Blackberries should also not be planted near thickets of wild strawberries, rose hips and roses... The berries also have common pests with these plants.
- Often, gardeners themselves become the cause of the spread of pests on berry plantations, buying seedlings not in large nurseries, but from random people, for example, selling at the metro. Or the option is even worse when the plant is purchased on trips abroad. Why can't this be done? Whatever huge berries they promise you, it is not worth buying varieties that are not tested and not adapted to your region... Due to a dubious plant, you risk creating an outbreak of an unknown disease in your garden, or spreading insect pests throughout the territory.
- Lack of proper plant care... In order for blackberries to stay healthy and delight you with a bountiful harvest, they need to be fed, sprayed from insects, and protected from weeds.
If you do not want to risk your blackberry harvest, it is better to take care of protecting the plant from pests in advance. To do this, you need to know with whom you have to fight. And the first enemies you may encounter are flies flying over the bushes.
Flies on blackberry shoots and berries: their varieties and how to deal with them
Among the flies that are not indifferent to blackberries, the following types of insects can be distinguished.
Raspberry stem fly
A small insect of gray color, the length of which does not exceed 5 mm. For the winter, the fly takes refuge in the top layer of the soil, and leaves its shelter just at the moment when young shoots of blackberries begin to grow... In southern Russia, this occurs in mid-to-late April, and in the middle lane - around mid-May.
Knowing the timing of the insect's departure, you can pre-treat the upper parts of the young shoots with drugs such as Actellik or Iskra. In case of severe damage to plantings by a pest (up to 50%), chemical treatment will be the only way to save the crop.
After the fly leaves the soil, it starts reproduction. The place for laying eggs is the sinuses in the upper parts of the blackberry leaves. The larva hatches from the egg, and it is she who causes the greatest harm to the plant, gnawing helical passages in the stems. As a result, the shoot begins to wither, starting from the top, and later blackens and rots along with the berries.
Such a plant can only be saved by cutting off damaged shoots. There are two ways:
- Pruning the shoot completely, to the very ground... This method is used as a last resort when the larva has already reached the base of the shoot. By cutting off damaged areas of blackberries in this way, you will lose a significant part of the crop.
- As soon as the tip of the shoot begins to fade, and the leaves turn black at the tips, immediately cut the branches in half... The cut parts of the branches must be burned in order to destroy the larvae. This method will not only help to preserve the harvest, but also multiply it, thanks to partial pruning.
And another way to destroy the raspberry stem fly is autumn digging of land under the bushes... This will allow you to get rid of the pest when it is in a defenseless state, laying down for the winter.
Raspberry shoot gall midge
Another name for this insect is the raspberry mosquito.... It is very difficult to detect it on a plant, until the moment when it has already caused significant damage, because its size is only 1.5-2 mm.
The female insect lays eggs under the bark of the plant, usually at the base of the leaf. A week later, larvae are born from the eggs, which begin to feed on the inner layers of the shoots... From this they begin to become covered with brown spots, which turn black over time. And a little later, the bark deteriorates completely, exposes the shoot, and it breaks. This usually occurs during the ripening period of the fruit.
To combat harmful insects, the following methods are used:
- Sanitary cleaning is required in spring and autumn, which consists in getting rid of the plant from diseased, damaged and fruiting shoots.
- To destroy an insect while it is still in the ground, you can dig up the ground under the bushes to a depth of 15 cm.
- In order to delay the departure of the pest, the root zone can be mulched with a peat layer of 8-10 mm.
- Chemical treatments against shoot gall midge carried out from mid-April, until the insect had time to leave the soil. In this case, shoots are sprayed, special attention should be paid to their lower part, as well as to the near-stem circle. Such insecticides as Calypso 480 KS, Karate, Iskra, Mospilan 20 SP, Arivo, Confidor help well.
Due to the high toxicity, you should not use such old products as Karbofos, BI-58, Fufanon. If you nevertheless decide to use them, then the solution should be no more than 0.75%.
When using chemicals to control insect pests, always compare the harm from crop loss with the harm that can be caused by the frequent use of toxic drugs. Sometimes, with a massive spread of an insect, it is easier to replace the planting material than to expose yourself to the risk of chemical poisoning.
Some gardeners in the fight against gall midge prefer to use folk remedies:
- Processing blackberries with powdered mustarddiluted in water.
- Use for spraying infusion of tansy (350 g dry tansy per 10 liters of water).
- Planting garlic and onions under the bushes.
Such methods, of course, will not be effective with a large number of insects, but if their population is small, it is better to experiment with them before using chemistry. Also these methods will be good as preventive measures.
Raspberry walnut
It is a small hymenoptera, the length of which does not exceed 3 mm. Nutcracker females during the flowering period of blackberries lay eggs in the shoots, and after a month, galls (swelling up to 10 cm in length) are formed at the site of damage to the shoots, inside which are the larvae of the fly. Because of the galls, cracks form in the bark, which makes the shoots brittle and incapable of fruiting. Over time, the shoots can dry out completely.
Methods of dealing with nutcracker:
- Before the beginning of the blackberry flowering period, the bushes are sprayed with Aktellik or Ambush.
- Everything shoots with galls must be cut off immediately and burn.
- When caring for a plant, you need be careful not to compromise the integrity of the bark on the branches. Cracks in the bark are a favorite place for fly-laying eggs.
Raspberry leaf sawfly
One of the most dangerous blackberry pests. In the sawfly, the females lay many eggs in a chain in the leaf petioles of the plant.... After the larvae emerge from them, the green leaves dry and die off. The larvae reach a length of 14 mm, are dark on top, light gray below, covered with hairs. They feed on bitter blackberry leaves from May to October. The foliage is usually eaten perforated, but sometimes only the skeleton remains of the leaf. In the first summer months they live mainly in the lower layer of leaves, eventually moving higher. They hibernate in warm spider cocoons right on the surface of the earth, among the fallen leaves.
If the number of this pest is high, then the blackberry can lose more than half of its leaf apparatus, which reduces the berry harvest this year. Besides, without leaves, the plant loses the opportunity to form healthy axillary budsrequired for the future harvest. And damaged shoots in winter, most often, freeze out.
Sawfly control measures:
- Loosening the soil under the bushes.
- Mulching basal circle.
- Mechanical collecting larvae, in case the plantation is small.
- Spraying plantings in the summer with insecticides with a short waiting period.
Despite all the unpretentiousness of blackberries, there is always a risk of losing the crop. Now that you know the main pests of the plant, be sure to take the time to take preventive measures to combat them. Exterminating flies on a blackberry is not easy, especially since the use of chemicals will not only destroy insects, but also reduce the quality of the fruit, and their safety for consumption.