Gall Aphid On Currants. Description. How To Fight? Folk And Chemical Remedies. Photo

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Gall Aphid On Currants. Description. How To Fight? Folk And Chemical Remedies. Photo
Gall Aphid On Currants. Description. How To Fight? Folk And Chemical Remedies. Photo

Video: Gall Aphid On Currants. Description. How To Fight? Folk And Chemical Remedies. Photo

Video: Gall Aphid On Currants. Description. How To Fight? Folk And Chemical Remedies. Photo
Video: How to Get Rid of Aphids Guaranteed (4 Easy Steps) 2024, March
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Currant - is in second place in terms of distribution in industrial plantings after strawberries. This is due to a number of factors, this is frost resistance and sufficient drought resistance and ease of reproduction (it is enough to stick part of the shoot into the soil) and the cheapness of planting material, coupled with a large and increasing number of varieties every year. However, currants have an abundance of diseases and pests and it becomes simply impossible to grow it without fighting them. Today we will talk about one of these pests, the gall aphid, which causes quite significant damage to currants, affecting both the appearance of the plant and its yield in a negative way.

Signs of defeat by gall aphid on currant leaves
Signs of defeat by gall aphid on currant leaves

Content:

  • What is the harm to currants from gall aphids?
  • Description of gall aphid
  • Why is the gall aphid called "gall aphid"?
  • Life cycle of gall aphid
  • The development process of an individual gall aphid
  • Gall aphid control measures
  • Prevention of gall aphid

What is the harm to currants from gall aphids?

To begin with, gall aphids mostly attack “colored” currants, that is, red, white, burgundy and the like, while golden currants and black currants (including those with green fruits) damage to a much lesser extent. Apparently this is due to the structure of the leaf, the leaf blades of the "colored" currant are somewhat softer, so it is easier to pierce them and suck the juice out of them.

As a result of the active vital activity of aphids, very ugly tubercles or swellings appear on the surface of the leaf blades of the currant, it seems as if the currant is affected by some kind of disease, but if the leaf is turned over, then we will notice insects under it - this is the gall aphid.

Gall aphids, sucking the juice from the currant leaf blades, leads to their strong deformation. This insect usually chooses the growth of the current year with the most delicate leaves on them, full of life-giving juice. This suggests that aphids are harmful not only in the current year, but also have a negative impact on the harvest of the next year, because new shoots actually stop growing and the bush does not develop, therefore, the potential for the harvest of the next season is reduced.

Description of gall aphid

Gall aphid, or gall leaf aphid, or red currant gall aphid (Cryptomyzus ribis) is a representative of a large family of aphids numbering more than four thousand individuals distributed throughout the world. The gall aphid is now found everywhere where currants grow. Gall aphids, in the absence of plantings of currants or suitable for feeding the leaf mass of this shrub, can live on crops such as mint, sage, oregano, lavender, thyme and purse, this must be borne in mind and, if possible, do not combine plantings of these crops.

Outwardly, the gall aphid differs little from the "familiar" aphid to us, which affects not only shrubs, but also trees. This is a small insect with an egg-shaped body, reaching a length of a couple of millimeters, mostly without wings and painted in a pale green-yellow hue. If you look more closely, you can see small hairs on the body of the gall aphid.

In one season, from four to two dozen generations of gall aphids can form, usually the higher the temperature in summer, the greater the gall aphid and, accordingly, the greater the harm from it.

Just one individual aphid can give birth to up to a hundred, and sometimes more of their own kind.

Gall aphid on currant leaf
Gall aphid on currant leaf

Why is the gall aphid called "gall aphid"?

In fact, when the gall aphid sucks the juice from the leaves of the currant, the plant tries with all its might to heal the holes formed from its pricks and forms a tissue that looks like a growth - gall, hence the name. If you do not fight the gall aphid, then the life-giving forces of the plant may not be enough to completely heal all wounds, and it may even die, drying out.

Among other things, like all sucking pests, gall aphids can carry various viral infections and, when a currant leaf is punctured, infect a plant with a virus, then even if the colonies of gall aphids are successfully destroyed, a viral infection will also have to be fought, and this is usually more difficult.

Life cycle of gall aphid

The categories of gall aphids are very interestingly distributed, a kind of hierarchy or botanically more correctly - polymorphism. Polymorphism means that different generations of gall aphids can be very different from each other, both phenotypically and perform completely different actions throughout their life.

For example, the founder aphid, it emerges from a laid egg and is a kind of mother of future generations of gall aphid, the most interesting is that it no longer lays eggs, but produces live aphids, that is, gives birth to them throughout the warm season. Only females are born, producing the subsequent generation.

Most of the aphids are represented by a group of female individuals who do not engage in sexual intercourse, they feed on the juice of currant leaves, do not have wings, and, therefore, practically do not move (usually only within the same plant), and those that are parthenogenetic give rise to the same individuals …

The next group is gall aphids, called settlers, they have fully developed wings and are activated when the aphid colony grows so much that it needs another place to feed, since the current plant is no longer able to completely feed all individuals. In this case, aphids with wings fly over to the next currant plant and produce a new generation of aphids, in fact, creating a new colony.

Gall aphids also have intermediate generations, for example, striped aphids, which can be both males and females without wings, but capable of having sexual intercourse and not giving birth to full-fledged individuals, but laying fertilized eggs.

And finally, there is a generation of bisexual aphids, the essence of which is to ensure the survival of the species, usually it is they who lay eggs in a variety of places, including weeds in the immediate vicinity of currants, in the bark of the same currant and similar places. From these eggs, the founding aphids usually emerge.

Currant bush affected by gall aphid
Currant bush affected by gall aphid

The development process of an individual gall aphid

After laying eggs, they can exist in this form for up to 250 days, sometimes a little more, usually this is enough with a large margin to survive the cold period. As soon as spring comes and the air warms up, the founding aphids begin to hatch from the eggs, which quickly move to a nearby currant plant.

Usually, mass reproduction of gall aphids occurs during the flowering period of the culture. The gall aphid is most strongly affected by the leaf mass at the very beginning of summer (often this is the beginning or mid-June). At the end of July, when the bulk of the leaf mass of the currant becomes rough, the surviving individuals settle on the plants that we described above, a generation is born there that has both male and female sexual characteristics, which then return to the currant plants to lay eggs. This usually happens at the end of August, sometimes in the middle of this month.

Gall aphid control measures

Firstly, you need to take a closer look at the plants and knowing the biology, which we have described quite thoroughly, more often pay attention to any changes in the leaf mass of currants. If you notice even insignificant foci of deformation of the leaf blades, you need to immediately apply measures, after making sure, by turning the leaf over, that this is really a gall aphid - small red spots will be visible, these are galls.

The very first way is to influence the currant bush with high temperature water. To do this, you need to bring the water to a boil and as quickly as possible, while the water is not too cold, pour it over the bush. Often this is done even before the appearance of the leaf mass in order to destroy the ovipositor of the pest, otherwise you can damage the leaves and even more so the inflorescences.

Assembling aphids by hand

If there are few affected currant leaves (literally 4-5 on each plant), then they can be torn off or cut off and burned outside the territory of the site. If one branch is affected and tubercles are swollen on it on most leaves, then the entire branch can be cut off, but the cut must be isolated with paint or garden varnish.

Signs of defeat by gall aphid on currant leaves
Signs of defeat by gall aphid on currant leaves

Folk remedies for the fight against gall aphid

The most common folk remedy is tobacco dust decoction. Usually they take ten liters of water (great if rainwater) and pour 250-350 g of tobacco dust there, after which they bring the solution to a boil, remove from heat, close with a tight lid and put in a dark room for three days. After this time, you need to strain the broth well, add a piece of antibacterial soap, stir everything well, fill the spray bottle and process the plants, trying to get exactly on the lower surface of the currant leaf.

If necessary, such processing can be carried out at least the entire warm season, with alternation of 5-6 days, just do not process the plants during the flowering period so as not to harm pollination and a couple of days before harvesting.

Infusion of marigolds is the second most popular remedy for combating gall aphids on currants. To obtain it, you need a lot of flowers - about 500 g. Marigold flowers can be crushed in any way convenient for you, pour ten liters of rain water and bring to a boil, then remove from heat, cover with a tight lid and put in a dark room for two days.

After this period of time, you need to add a piece of antibacterial soap to the infusion (it, as in the first case, will play the role of an adhesive), strain everything thoroughly, fill the spray bottle and treat the affected plants with it, trying to get also on the lower part of the leaf. Treatments should be carried out at the same time as when treating with a decoction of tobacco dust. Doses can be different, depending on the number of affected leaves, the main thing is that they are all moistened.

Previously, mustard was also used, but since it turned out that this is the strongest allergen, it was decided to refuse its use.

Chemical measures to control gall aphids

If folk control measures do not help, you can start using chemicals, but it is not advisable to immediately use insecticides that are hazardous to the environment, first pay attention to biological preparations, they may help. When using biological preparations, remember that this is also a kind of "chemistry", therefore, the use of protective gloves and a respirator should not be abandoned and these treatments should be carried out in sunny, cool, but calm weather.

Biological preparations are made from bacterial spores, as well as various parts of fungi and even viral elements. As soon as they enter the body of a gall aphid through the proboscis, with which it sucks in juice, they paralyze, and sometimes completely destroy its intestines, the aphid perishes. For example, we will give drugs that gardeners respond positively to, these are Bitoxibacillin, Aktofit and Avertin. Remember, however, that when using them, you also need to carefully read the instructions on the package, in no case exceed the dose, but also do not save, otherwise there will simply not be the desired effect from their use.

If there are so many gall aphids on currants that it is already impossible to cope with it with simple preparations, then insecticides can be used, this is, as a rule, serious chemistry, therefore, protective equipment must be worn, find out what the distance should be to the nearest bee farm and a stocked lake or river and strictly in calm weather, it is better to start processing early in the morning or late in the evening.

Remember that in this case it is better to use approved drugs, not to use the old ones "lying around" on the shelf. It is advisable to carry out the first treatment even at the stage of opening the buds (if the currant plantation was severely affected by aphids last season), it is advisable to re-process it after harvesting (if the gall aphid is rampant in the current year). But of course it all depends on the drug - read the instructions, perhaps the drug allows processing at other times.

Gardeners speak well of the drugs: Aktelik, Confidor Maxi, Vofatox, Calypso and Proteus.

Dying leaves of currant after defeat by currant gall aphid
Dying leaves of currant after defeat by currant gall aphid

Prevention of gall aphid

Well, in conclusion, we will tell you about the prevention against gall aphids, because any disease, and even a pest, including, is better not to let on your site than to waste energy to drive out the intruder.

It is better to start preventive treatments early in the spring, even before the disclosure, or even better before the currant buds swell, and you can continue in late autumn (November) after all the leaves from the plant have fallen off. Quite effective are the treatments at this time of both plants and the bite part with Nitrafen. Nitrafen very effectively fights the ovipositor, but it can harm the leaf mass and even more so the flowers. Usually a 4% solution of the drug is used, diluting 4 ml in a bucket of water. This amount is enough for 20 adults or 40 young currant bushes if you use a spray bottle.

Do not forget about folk preventive measures - plant marigolds around the perimeter of the site, sow chamomile or calendula.

Be sure to do a weekly weed control from May to mid September. Remember that the carrier of the pest, a kind of "rest home" or "maternity hospital" for the gall aphid is the purse, it simply should not be on the territory of your site.

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