Contents
Growing tomato seedlings at home, everyone hopes to get strong healthy bushes, which, later planted in the ground, will give a bountiful harvest of sweet and tasty fruits. And it is all the more insulting to watch how suddenly these bushes begin to wither and wither for some reason. Approaching them and examining the bushes of seedlings closer, you do not immediately notice small annoying butterflies flying over the tomatoes in a swarm. But an experienced gardener immediately understands that he is dealing with the most dangerous and difficult to remove pest – the whitefly. And if you do not start fighting it as soon as possible, then it will be more and more difficult to bring it out.
Pest Biology
The whitefly is a small flying pest that is somewhat reminiscent of the smallest white moth. They are usually found on the underside of the leaves, their eggs are usually attached there, and at the same time the larvae look like grayish grains. Insects feed on the juice of leaves and stems of seedlings. No wonder it is often also called “seedling moth”. Sucking out the juice, whiteflies secrete a sticky substance that is deposited already on the upper surface of the underlying leaves. It is a favorable environment for the development of soot fungi, the so-called black. 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, curliness, 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 multiplies quite quickly. Therefore, the whitefly on tomato seedlings is a terrible disaster and it is imperative to find out how to deal with it. By itself, she will not go anywhere, and after the tomatoes she will switch to other suitable plants.
To understand how best to deal with the whitefly, it is necessary to study its biological characteristics well. Firstly, even if you destroy all adults with a powerful insecticide, the fight will not be over, since no pesticides work on:
- Eggs protected by a special waxy substance;
- Insects in the nymph stage, when they stop feeding and are also covered with a dense substance (pupate).
Cycle of life
Whiteflies usually lay their eggs in the open field in spring, in rooms and greenhouses they can do this all year round. The larvae emerge from the eggs in a week and begin to look for a comfortable 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 are reborn as adult whiteflies and begin to mate. The full development cycle is 25 days, and the life expectancy of one female is about 30 days. During her life, she manages to lay about 140 eggs.
Whitefly Control Means
Given the adaptability of the pest to life in rooms and greenhouses and the complex life cycle with moments when the whitefly becomes invulnerable, it is necessary to use the whole range of measures in order to end 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 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, and most importantly, you don’t need to spray tomato seedlings with Aktara’s solution, you just need to shed it thoroughly under 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 at once, you can try to make a particularly concentrated Aktara solution, that is, increase the concentration by 3-4 times. There will be no harm to tomato seedlings, but the whitefly will most likely be done away with.
- Verticillin – this remedy is made from spores of the fungus, therefore it is relatively harmless to humans and plants, but detrimental to the whitefly. About 25 ml per liter of water is diluted and the tomato seedlings are sprayed twice with the resulting solution with an interval of 7-10 days.
In greenhouses, other means can also be used:
Confidor, Vertimek, Intavir, Fitoverm, Pegasus, Talstar. There are also hormonal agents for the destruction of eggs and larvae of the whitefly in the greenhouse – Admiral and Match.
Mechanical means
If you are a categorical opponent of the use of chemistry in the house, especially for processing future tomatoes, then there are quite effective mechanical means to combat the whitefly.
You can take small pieces of plywood, paint them yellow and smear with petroleum jelly or castor oil. Whiteflies are attracted to the yellow color and quickly stick to surfaces. Traps can be changed, or wiped and lubricated again. It is also effective to use ordinary fly tapes against whiteflies.
With a large accumulation of insects on seedlings, they are quite effectively removed with 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 gaining popularity.
Some of these insects are Encarsia (Encarsia Formosa) and Trikhaporusi (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 the contact of Encarsia with whitefly larvae.
Another representative of the insects, with the help of which they successfully fight the whitefly, is the macrolofus bug. About five bugs are released per square meter, you can repeat the release in two weeks to consolidate the effect.
Folk remedies
Oddly enough, they effectively fight the whitefly 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 the whitefly, they must be repeated regularly, every week until the pest has completely disappeared. It is desirable to combine the processing of 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 the first place, of course, is a solution of garlic. To prepare it, you need to take 150-200 g of garlic, finely grate, 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 damaged tomato seedlings are sprayed with a diluted solution.
To combat the whitefly, an infusion of yarrow is used. 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 a day. After infusion, the solution is filtered and seedlings of tomatoes are treated with it. The largest leaves are best wiped with a napkin dipped in the prepared solution.
A tincture of dandelion roots and leaves can also help in the complex fight against whiteflies. In order to prepare it, you need to take 40 g of all parts of the dandelion, pour them with 1 liter of water and insist for two hours. After that, the tincture is filtered and it can be sprayed with the leaves of tomato seedlings. The drug is practically not stored, so it should be used immediately after preparation. To enhance the effectiveness of the proposed funds, laundry soap is added to them, which promotes the adhesion of drugs to tomato leaves.
An interesting remedy against whiteflies is an emulsion solution used in the treatment of scabies. This remedy is purchased at a pharmacy. 50 g of the drug is diluted in a liter of water and damaged tomato bushes are sprayed with an interval of one week.
Prevention of the spread of whiteflies
Theoretically, it can also be brought in with soil that will be infected with its eggs. Therefore, all new plants, as well as purchased seedlings, must be carefully examined and undergo a mandatory two-week quarantine. The whitefly does not like the cold very much and dies already at temperatures below + 10 ° C. Therefore, it is useful to ventilate the premises from time to time and prevent crowding of plants. In the greenhouse, the most effective way of prevention is to completely freeze it in the winter.
With the comprehensive observance of all the above measures to combat the whitefly, you can protect your tomato seedlings and get rid of the harmful insect.
