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By growing tomato seedlings at home, everyone hopes to get strong, healthy bushes, which, later planted in the ground, will produce a bountiful harvest of sweet and tasty fruits. And it’s even more offensive to watch how suddenly these bushes begin to wither and wither for some reason. Approaching them and taking a closer look at the seedling bushes, you do not immediately notice small annoying butterflies flying up in a swarm over the tomatoes. But an experienced gardener immediately understands that he is dealing with the most dangerous and difficult to remove pest - the whitefly. And if you don’t start fighting it as soon as possible, then it will be more and more difficult to remove it.
Pest biology
The whitefly is a small flying insect pest that somewhat resembles a tiny white moth. They are usually found on the underside of leaves, where their eggs are usually attached, as well as larvae that look like grayish grains. Insects feed on the sap of leaves and stems of seedlings. It is not for nothing that it is often called “seedling moth”. When sucking the juice, whiteflies secrete a sticky substance, which is deposited on the upper surface of the underlying leaves. It is a favorable environment for the development of sooty fungi, the so-called mob.The surface of the leaf turns black, and the leaves and shoots themselves dry out and die.
In addition, the whitefly carries a number of very dangerous viral diseases that cause leaf chlorosis, curl, and jaundice and cannot be treated. They, in turn, cause deformation of shoots and ripening fruits.
Due to the invasion of this harmful moth, you can very quickly lose all the results of your labors, since it reproduces quite quickly. Therefore the whitefly on tomato seedlings is a terrible disaster and it is imperative to figure out how to deal with it. It won’t go anywhere on its own, and after the tomatoes it will move on to other suitable plants.
To understand how best to deal with whitefly, it is necessary to thoroughly study its biological characteristics. Firstly, even if you destroy all adult individuals using a powerful insecticide, the fight will not be over, since no pesticides have an effect on:
- Eggs protected by a special waxy substance;
- Insects are in the nymphal stage, when they stop feeding and also become covered with a dense substance (pupate).
Cycle of life
Usually in open ground whiteflies lay eggs in the spring; in rooms and greenhouses they can do this all year round. The larvae emerge from the eggs after a week and begin to look for a convenient place to live. Having found such a place, they turn into nymphs, and, being absolutely motionless for 14 days, remain practically invulnerable to a variety of chemicals. Then they degenerate into adult whiteflies and begin to mate. The full development cycle is 25 days, and the lifespan of one female is about 30 days. During her life she manages to lay about 140 eggs.
Whitefly control agents
Considering the pest’s adaptability to living in rooms and greenhouses and its complex life cycle with moments when the whitefly becomes invulnerable, it is necessary to use the entire range of measures in order to put an end to it once and for all.
Chemical methods
To combat adult flying whiteflies, chemical control agents are quite effective, but given that it is undesirable to use highly toxic agents in rooms, especially on tomato seedlings, the following drugs are the most popular:
- Aktara – is the most optimal means of protection against whiteflies, since it is a systemic drug and has a long period of action (3-4 weeks). Well, the most important thing is that you don’t need to spray tomato seedlings with Aktara’s solution; you just need to pour it thoroughly at the root. It is advisable to repeat the treatment three times with an interval of one week. If you want to try to destroy the whitefly in one go, you can try making a particularly concentrated Aktara solution, i.e. increase the concentration by 3-4 times. There will be no harm to the tomato seedlings, but the whitefly will most likely be eliminated.
- Verticillin – this product is made from fungal spores, therefore it is relatively harmless to humans and plants, but is harmful to whiteflies. Dilute about 25 ml per liter of water and spray the tomato seedlings with the resulting solution twice with an interval of 7-10 days.
In greenhouses it is possible to use other means:
Confidor, Vertimek, Intavir, Fitoverm, Pegasus, Talstar. There are also hormonal agents for the destruction of whitefly eggs and larvae in the greenhouse - Admiral and Match.
Mechanical means
If you are a categorical opponent of using chemicals in the house, especially for processing future tomatoes, then there are quite effective mechanical means to combat whiteflies.
You can take small pieces of plywood, paint them yellow and coat them with Vaseline or castor oil. Whiteflies are attracted to the yellow color and quickly stick to the surface. Traps can be changed, or they can be wiped and lubricated again. Using regular adhesive fly tapes against whiteflies is also effective.
If there is a large accumulation of insects on seedlings, they can be removed quite effectively using an ordinary vacuum cleaner.
Regular washing of seedlings with a solution of potassium soap also protects quite well from adult whiteflies.
Biological agents
With large quantities of tomato seedlings, as well as in greenhouses, the method of using predatory and parasitic insects that feed on whitefly larvae and eggs is becoming very popular.
Some of these insects are Encarsia Formosa and Encarsia partenopea. It is enough to release three individuals per square meter. The method has an efficiency of up to 98%. It is especially effective on tomatoes, since the structure of the leaves does not prevent Encarzia from contacting whitefly larvae.
Another representative of insects that can be used to successfully combat whiteflies is the Macrolophus bug. About five bedbugs are released per square meter; the release can be repeated after two weeks to consolidate the effect.
Folk remedies
Oddly enough, they fight whiteflies quite effectively with the help of a variety of herbal infusions. These treatments are absolutely safe for humans and tomato seedlings, but in order for them to be effective against whiteflies, they must be repeated regularly, every week, until the pest completely disappears. It is advisable to combine treatment with folk and mechanical means. Before using folk remedies, you must first thoroughly bathe the affected tomato seedlings in soapy water to mechanically remove most of the whitefly.
In first place, of course, is the garlic solution. To prepare it, you need to take 150-200 g of garlic, finely grate it, add a liter of water and leave for 5-7 days. The container in which the product is prepared must be very tightly closed. The resulting concentrate is diluted with water - 6 grams per 1 liter of water and the damaged tomato seedlings are sprayed with the diluted solution.
To combat whiteflies, use an infusion of yarrow. To prepare it, 80 g of common yarrow are crushed, poured with a liter of hot water and left to infuse in a dark place for 24 hours. After infusion, the solution is filtered and tomato seedlings are treated with it. It is better to wipe the largest leaves with a napkin soaked in the prepared solution.
A tincture of dandelion roots and leaves can also help in the comprehensive fight against whiteflies. In order to prepare it, you need to take 40 g of all parts of the dandelion, pour 1 liter of water over them and leave for two hours. After this, the tincture is filtered and you can spray it on the leaves of tomato seedlings. The drug is practically not stored, so it must be used immediately after preparation.To enhance the effectiveness of the proposed products, laundry soap is added to them, which promotes the adhesion of the drugs to tomato leaves.
An interesting remedy against whiteflies is an emulsion solution used in the treatment of scabies. This product is purchased at the pharmacy. Dilute 50 g of the drug in a liter of water and spray on damaged tomato bushes with an interval of one week.
Preventing the spread of whitefly
Theoretically, it can also be brought in with soil that will be contaminated with its eggs. Therefore, all new plants, as well as purchased seedlings, must be carefully inspected and undergo a mandatory two-week quarantine. The whitefly does not like the cold very much and dies at temperatures below +10°C. Therefore, it is useful to ventilate the premises from time to time and prevent crowding of plants. In a greenhouse, the most effective way of prevention is to completely freeze it in the winter.
With comprehensive compliance with all the above measures to combat whitefly, you can protect your tomato seedlings and get rid of the harmful insect.
Guys, don't joke! Not one of the remedies you listed is suitable for whiteflies, although the description says that it works. I’ve been working in greenhouses on a serious scale for 17 years and this crap doesn’t do anything. It’s better to use my own remedy - I mix 7 different preparations for whiteflies, but next time it’s already It’s not effective, you need to remove one thing and add another, and you may not always be lucky. Such a little crap, but it quickly gets used to the drugs. You can check it and thank me - theory is dead without living practice.