Gall aphid on currant

This pest has several names. The most famous is the gall aphid. It is also called currant blister aphid, hairy currant aphid, gall leaf aphid, but officially it is called – redcurrant aphid (Cryptomyzus ribis). And this is not accidental – this pest most often infects red currants (and white ones, but from a botanical point of view, this is the same plant). And very rarely black.

What does gall aphid look like on currants

The gall aphid has a very complex and amazing life cycle. In the colonies of this pest, there is no simple division into females and males – everything is much more complicated there. All individuals are divided as many as 5 different forms!

Founders. These are wingless females that are born in early spring from eggs laid in autumn. They are the founders of the colonies. But they themselves do not lay eggs – they are viviparous individuals, and they produce offspring without the participation of males – they do not need fertilization. The offspring of the founder are produced throughout the warm season and exclusively females are born to them.

Wingless virgins. These are the same females that the founding aphids give birth to. They are also viviparous. And they also give birth to females – wingless virgins. But for the time being.

Winged virgin migrants. They are born to wingless virgins at the height of summer, when the currant leaves are coarsening and the aphid colony becomes too large to feed on one plant. Since these individuals are able to fly, they leave their native currants and settle on plants with more delicate leaves, as a rule, representatives of the Lamiaceae family, which, for example, include mint and sage. But if there is a cleaner (stakhis) on the site, and he is a frequent guest in flower beds, winged aphids will prefer him. There they create new colonies and breed until autumn. And in August-September, virgin migrants return to the currant bushes.

Normal females (wingless) and males (winged). They are produced by winged virgins, returning to the currant. Normal females and males, unlike other forms, they are not viviparous. These individuals mate and lay their eggs in bark cracks on currants. From which aphids-founders appear in the spring and the cycle repeats.

Interesting facts about the gall aphid (we do it in the form of a table)

What is dangerous gall aphid on currants

Leaves affected by gall aphids are deformed. Currant lags behind in growth, young shoots give a weak increase, the yield is significantly reduced (2).

Nog is not everything – the gall aphid transfers viral diseases to currants that cannot be treated.

Signs of the appearance of gall aphids on currants

The main symptom is red swollen spots on the leaves (galls) of cherry red color (3). They are formed in those places where the aphid sucks the juices from the plant. There are many of these spots on young leaves and they are scattered over all surfaces. On older leaves, the galls are bright and large.

Reasons for the appearance of gall aphids on currants

Gall aphids can fly to the site from neighboring gardens. Or it can be brought in with infected planting material, especially if you buy seedlings of red and white currants in the fall without leaves – the aphids themselves will no longer exist, and it is unrealistic to see eggs on the bark.

How to deal with gall aphids on currants

Gall aphid is the most dangerous pest, but if it brings viruses to currants, write wasted. Viral diseases are incurable, the bushes will have to be cut down. Therefore, it is imperative to fight the pest.

Folk methods

The simplest, and perhaps one of the most effective ways to deal with gall aphids without the use of chemicals is to remove the affected leaves. Moreover, they need to be cut off immediately, as soon as the first red spots are found – aphids are prolific and spread throughout the plant very quickly. Of course, the leaves must be burned.

There is no point in cutting off the affected leaves in the second half of summer, because the winged individuals have already moved to intermediate plants and will return to currants in the fall.

Preparations

With a mass infection of currant aphids, you need to use chemicals – you can’t cut off all the leaves on the currant, it will die.

Aktara. This is a systemic insecticide – it penetrates the leaves of the plant, the aphid absorbs it along with the plant sap and dies. It is effective just against pests that hide from the underside of the leaves (4), as gall aphids do – it is not easy to get them there when treated with contact preparations. It is easy to use: 2 g of the drug should be diluted in 10 liters of water and carefully sprayed with currant leaves. The first treatment is carried out before flowering. The second – after the harvest.

It’s important

During fruiting, currants cannot be treated with Actara, since the waiting period (the time that the drug is stored in the plant) is 60 days.

Kinmix. Contact preparation against a complex of pests on various fruit and berry crops, including gall aphids on currants. It is used as follows: 4 g of the preparations are diluted in 10 liters of water and the plants are sprayed so that the preparation wets the underside of the leaves well. Consumption rate – 0,5 – 1 l per bush. During the season, you need to carry out 2 treatments: before flowering and after harvesting.

The waiting period for Kinmiks is shorter than for Aktara – only 20 days.

Prevention from infection with gall aphids on currants

Only one piece of advice can be given here – buy red and white currants in spring or summer, in containers. When there are leaves, it is immediately clear that the bush is sick. But with autumn seedlings without leaves, you can easily bring the pest into the garden – you won’t be able to see the aphid eggs on the shoots.

Popular questions and answers

We talked about gall aphids on currants with agronomist-breeder Svetlana Mikhailova.

Sources of

1. Ivanovskaya O.I. Aphids of Western Siberia. Part 2 // Novosibirsk, Science, 1977
2. Savkovsky P.P., Atlas of pests of fruit and berry crops // Kyiv, Harvest, 1990
3. Verderevsky D.D. Agronomist’s Handbook for Plant Protection. A team of authors edited by Verderevsky D.D., Polevoy T.N., Shapa V.A. // Chisinau, “Cartya Moldovenyasca”, 1968 – 724 p.
4. State catalog of pesticides and agrochemicals approved for use on the territory of the Federation as of July 6, 2021 // Ministry of Agriculture of the Federation https://mcx.gov.ru/ministry/departments/departament-rastenievodstva-mekhanizatsii-khimizatsii- i-zashchity-rasteniy/industry-information/info-gosudarstvennaya-usluga-po-gosudarstvennoy-registratsii-pestitsidov-i-agrokhimikatov/