Gall aphid on currant bushes - how not to miss the moment

The ugly swelling and growths on the leaves of red currant at first glance look like a disease, but this worked gall aphid. Eating plant juices, it causes its deformation - traces of life are like healed wounds. Worst of all, a gluttonous and prolific insect prefers young shoots, which means it harms not only the current state of the bush, but also reduces the chances of a good harvest in the future.

Description of the insect, its harmfulness

Gall leaf aphid is one of 4 thousand species of aphid family that live on the planet. The distribution area of ​​the redcurrant pest - Europe, the Caucasus, Siberia, Central Asia, is currently found everywhere where this berry shrub is grown.

The forage base and the host plant for the species is precisely red and white currants, sometimes it can slightly populate black currants. As an optional (intermediate) plant uses herbs of the family Iasnatkovye (labioecious). In the second half of summer, or if the colony is overcrowded, the aphids populate the mint, sage, oregano, thyme, lavender growing nearby, and the cleaner loves it very much.
In structure and outwardly, the gall aphid is similar to its many relatives. A small egg-shaped insect reaches a length of no more than 2–2.3 mm. The bulk of the representatives are wingless; winged individuals appear in later generations. Among the differences is a pale, greenish-yellow, almost transparent cover, as well as the presence of small hairs on the body, which is why it is also called hairy.

From 4 to 19 insect generations develops per season - the warmer the region, the more. It is fertility that aggravates its harmfulness. The one and only aphid founder gives life to tens, or even hundreds of thousands of sucking pests. What are the sizes of harm from the gall aphid settled on a currant?

• Sucking juices, it drains the shoots. To "heal" the wounds, the plant produces special tissues that form outgrowths - galls at the site of damage. If you do not fight aphids, it will spawn new generations and live on branches until they dry out.
• Attracts other pests to the garden, such as ants. Not only do they "graze" aphids, protect its entomophages, contribute to its spread, they also feed on the juice of berries of the same strawberries or grapes.
• Gall aphids can be carriers of viral infections of plants.

Young shoots affected by aphids, even after the destruction of the pest, lag behind in growth, recover for a long time, therefore, their productivity decreases.

Note! Thunderstorm aphids - entomophagous insects, in particular ladybugs, lacewings, grunts. But if ants take care of the colony, they will not let them close.

"Family" gall aphid hierarchy

The life cycle of leaf gall aphids is inherent in such a phenomenon as polyformism. This means that different insect generations can differ not only externally, but also perform different functions.What does the aphid hierarchy look like during the growing season and the complete transformation cycle?

1. Founding aphid hatching from an egg. She is the “mother” of all generations that will appear during the season. This parthenogenetic individual, besides viviparous, that is, gives birth to ready-made insects and only females, which in turn produce the next generation of offspring.
2. Virgin aphids represent the bulk of the gall aphids that we observe on currants. They have no wings, so insects are constantly on the host plant, parthenogenetic females hatch their own kind.
3. Aphids-settlers - winged generation, they perform a slightly different function. When the colony grows or the food supply is depleted, they fly to a new place and establish the next settlement.
   
4. Aphid strips are a transitional generation of an insect from which females capable of laying eggs and males emerge.
5. Aphid females and aphid males are a bisexual generation that provides wintering of the species. Of the eggs laid in the bark of the currant stalks, the aphid founders appear in spring.

How does pest develop?

Gall leaf aphid lays eggs under the bark of branches of red currant, closer to the kidneys. Here it can be up to 9 months depending on the climatic zone and weather conditions. In the spring, as soon as the buds begin to bloom, the founders emerge from the eggs and populate the plant.

Active reproduction of the insect begins from the moment of flowering of the bush. The peak of harmfulness falls in June, when the colony reaches its maximum size. In the second half of summer, currant leaves coarsen, aphids begin to settle on intermediate plants. They feed on several more generations of the pest. A bisexual generation appears here that will return to the currant to lay eggs. It happens closer to the fall.

Ways to combat leaf currant aphids

An attentive gardener will not miss the appearance of gall aphids on currants, he will immediately take adequate control measures. It is important to notice the deformation of young leaves at the initial stage of vegetation. On them, the galls look like small red spots. In addition, the presence of a pest in the past season is a serious reason to start preventative measures on the bush as early as possible.

Berry bush infection prevention

In order not to puzzle how to get rid of gall aphids, you can try to prevent its appearance. What is recommended to do for this?

1. Early in the spring, before the buds open, or in the fall, after leaf fall, spray the bushes and the near-trunk zone with a solution of nitrafen. The drug is harmful to the leaves (burns them), so you can not be late with the processing. Its advantage is that it destroys the eggs of wintering pests. For currants apply a 3% solution (30 ml / l of water). To process an adult bush, you need about 0.5 liters.
2. To protect the berry from settling the insect from the outside, for example, from neighbors, it is recommended to plant plants with a pungent odor next to the berry shrub - calendula, marigold, chamomile.
3. To destroy weeds in the garden, especially the cleaner (the second name is deaf nettle). This perennial weed is an intermediate host of gall aphids, for which she will thank you.

Advice! One of the options for killing gall aphid eggs, which can be found in the literature, is to scald a bush with boiling water in spring. How effective this can only be shown by one's own experience.

Mechanical way

At the initial stage of infection, mechanical removal of shoots with a colony of pests is recommended. The bush is carefully inspected, all branches are cut with the slightest deformation of the leaves. If at least a few individuals remain, they will multiply rapidly again. Cut shoots must be disposed of, best burned. This control method gives a good effect in combination with the processing of natural insecticides.

Advice! Along with young growth, the insect loves fatty shoots very much. When spring pruning the bush, first remove the wen, cut out all the excess zero shoots.

Spraying with natural insecticides: recipes

Some plants contain in large quantities fungicides, pyrethrins, other substances that destructively affect gall aphids, therefore they are widely used to control pests. To enhance the negative impact in the infusions, it is recommended to add soap, which envelops the insect, blocks its access to oxygen (aphids breathe through the skin). Here is a recipe for several popular infusions.

1. Based on tobacco dust. To prepare a bucket of infusion, you need 300 g of herbal preparation. It is poured with boiling water and insisted for 2-3 days. The settled solution is filtered, 100 g of soap dissolved in water are added. You can also use tar soap or other liquid detergent, for example, for dishes.
2. Infusion of marigolds. For infusion, take half a bucket of crushed flowers, fill them with 10 liters of hot water and insist for 48 hours. In the finished strained infusion add 50 g of liquid soap.
3. Infusion of mustard powder. To prepare 10 l of working solution, you need 25 g of dry mustard. First, a concentrate is prepared - mustard powder is poured with a liter of boiling water, insisted for 2 days. Then it is brought to full volume, soap is added.

Biochemical method of struggle

When the gall aphid has already bred, chemical agents cannot do without it. Given the toxicity and shelf life of toxic components in plant tissues, it is recommended to spray currants with insecticides at the budding stage, and the second time after harvest. Long-term effect gives spraying with the preparations Calypso, Confidor Maxi, Actelik, Wofatox, Proteus.

In addition to chemical insecticides, the modern "herbal pharmacy" offers biological products that are harmless to humans and domestic animals. They are made from spore bacteria, components of fungi, viruses. Getting into the body of an insect with food, they act on the intestinal tract, paralyzing and destroying it. Examples of such drugs are Avertin, Actofit, Bitoxibacillin.

Fighting aphids on currant: