How to fight whiteflies in a greenhouse: 5 effective ways

The topic of how to deal with whiteflies in a greenhouse is of interest not only to novice gardeners, but also to people who have extensive experience in plant growing. The rapid reproduction of the insect leads to the fact that the plant does not receive enough moisture and useful components and begins to wither. There are many ways to get rid of it, from manual collection or spraying with pesticides, to setting up traps or introducing antagonistic insects (predators).

Tomatoes affected by whitefly Source stopklopu.com

How to detect the presence of whiteflies

The insect has an original appearance, so it is simply impossible to confuse it with others:

• The body is light green, and the wings are milky white.
• Superficially it resembles a moth, but has a more elongated body, 1-3 mm long.
• Whitefly larvae may have a yellowish or gray tint, and their mobility depends on the period of the life cycle.

This is what a whitefly looks like Source wp.com

Tomatoes affected by whitefly Source stopklopu.com

Types of whiteflies

The most described species of all members of the family is the tobacco whitefly, a dangerous quarantine object that has spread throughout the world. The body of an adult insect, whose lifespan is 14 days, is yellow, the wings are white, and the legs are light yellow. The female lays from 50 to 300 eggs. This species feeds on vegetables, melons, flowers and industrial crops, medicinal plants, many types of weeds and forage grasses. They also parasitize fruit, citrus and woody plants. Tobacco whitefly poses a particular danger to plants in greenhouses and conservatories. This pest carries up to 100 types of viruses, many of which can lead to crop loss. Biological enemies of the tobacco whitefly include lacewings, predatory bugs and some types of ladybugs.

In addition to the tobacco whitefly, the most common and described species of the family are:

• greenhouse or greenhouse whitefly is a pest that damages cucumbers, tomatoes and some flowering plants;
• cabbage whitefly;
• citrus whitefly - this quarantine pest of citrus fruits is found in China, Japan, India, America and the Caucasus;
• strawberry whitefly, found in Europe.

How to prevent it from appearing

Actions related to the fight against whitefly should begin in the fall, immediately after harvest. To do this, you need to completely remove plant debris from the greenhouse. This way you will reduce the likelihood of the pest getting into the ground, where it can easily overwinter and wait until spring.

In the spring, at the seedling propagation stage, do not place seedlings next to home crops. The whitefly loves geraniums and pelargonium, from where it moves to young shoots, and with them ends up in the greenhouse. Therefore, try to ensure that indoor flowers and seedlings of tomatoes, cucumbers, and peppers are located on different windowsills.

Aphids or whiteflies?

First of all, learn to identify the first signs of a pest in the greenhouse:

• Stickiness is felt in different places of the plants.
• Leaves are deformed, curled and wilted.
• On the inside of the leaves you see larvae with a waxy coating.
• Some leaf blades of vegetable crops are covered with yellow spots, but the boundaries are unclear.

And finally, just touch the infected bush - a whole flock of small white flies immediately rose and flew to another bush? These are definitely whiteflies. And, if you are not squeamish, take a closer look at one of them - is it similar to the photos below? Let's put it this way: this is a serious threat to your future greenhouse crop. And the strength of these parasites is that there are many of them - hundreds and thousands of small pests that literally draw out all the juices from the leaves and stems. If you do nothing, you will lose all your work in a couple of days.

Please note that if a black coating is also noticeable on the sticky secretions of the parasite, then the plants are already infected with an additional sooty fungus. Such bushes can only be pulled out and immediately burned. Unfortunately.

Fighting methods

The greenhouse whitefly is a frequent enemy of gardeners in central Russia. There are a lot of methods to combat insects, let's look at the most effective of them using specific examples.

Whitefly and its larvae Source vseprodachu.ru

Manual method

The manual or mechanical method of controlling whiteflies refers to the collection of insects and clusters of eggs and larvae (if there are small numbers of them). If the concentration of moths is higher, they can be knocked down with a stream of water from a watering hose. After the plants are cleaned, each leaf (on both sides) is wiped with a solution of laundry soap (proportions 1 to 6). At higher concentrations, a household vacuum cleaner can be used. With its help, you can not only knock down harmful tenants, but also spray soap concentrate.

How to deal with whitefly Source vosaduly.ru

Healthy! This method is considered the most time-consuming and least effective. It is used at the early stage of colonization and in the presence of a small number of plantings.

What is the danger of whitefly

Of the one and a half thousand species of insects of the Aleurodidae family, the greenhouse whitefly poses a particular danger to agricultural crops. The homeland of this harmful moth is South America. This is what explains the special “love” of whiteflies for greenhouses and greenhouses, where a warm and humid climate is maintained.

Whiteflies

In one calendar year, the whitefly is capable of producing 15 generations. When the air temperature drops to 10-12 degrees, the pest’s ability to reproduce decreases, but the butterfly calmly waits out the cold weather in the top layer of soil or in plant debris.

Greenhouse whitefly

Whitefly growth stages

The complete transformation of the pest from an egg into a mature individual occurs in 25-40 days. The more favorable the conditions for the butterfly’s existence—humid air and room temperature—the faster the whitefly “ripes.” The life cycle of the whitefly consists of four “ages”, during each of which the butterfly causes harm to garden and vegetable crops.

Whitefly development cycle

1. Tramp larva - hatches 11-12 days after laying eggs. The size is 0.25-0.3 mm, intensively spreads over the surface of the leaves in search of the most favorable habitat.
2. The nymph larva - after 5-6 days, is tightly attached to the underside of the leaves of the plant. Having pierced the leaf, the nymph provides itself with nutrition from the juice of the foliage and remains completely immobile until reaching the next stage of growth. It is difficult to detect visually; it looks like a thin greenish scale. During its existence, it becomes covered with a waxy secretion, which makes it invulnerable to insecticides.
3. The pupa is the final stage of whitefly development and lasts from 7 to 30 days.
4. Formation of an imago (adult whitefly), ready to devour the plant.

The exact life cycle of a whitefly

An adult female whitefly lives about 30 days, during which time she can lay up to 140 eggs. For this reason, one greenhouse plant can often become a haven for harmful butterflies at all stages of development - from colonies of eggs to hundreds of adult moths.

A leaf of a calathea that has suffered from whiteflies: when held up to the light, numerous punctures and bites are visible

In the absence of timely treatment, the plant is doomed to rapid death - the larvae deprive it of its vitality by drinking the juice, and the adults eat the fleshy part in a matter of days. In addition to the direct threat, whiteflies are carriers of many viruses. The larvae produce a sugary substance, which is a beneficial environment for fungi to live in. Very often, in greenhouses where whiteflies are common, plants are affected by black fungus, a type of sooty fungus.

Black fungus (sooty fungus)

Biological countermeasures

Another no less effective, but completely environmentally friendly way to combat it is the use of other insects - competitors. By planting just a few representatives of one species or another, you can completely disrupt the pest plantation without the risk of harming the plantings. Below are some of the most inveterate enemies.

A bug eating whiteflies Source mrdachnik.com

Macrolophus caliginosus is a voracious predator bug that feeds on many insect pests. It is used as one of the highest quality and proven methods of combating aphids, whiteflies, spider mites, and tomato leafminer moths. It is advisable to populate them every 2 weeks for a month. After this, the insects will take root and begin to independently maintain their population.

The most beautiful defender of your greenhouse Source fotokto.ru

The ladybug is one of the main enemies of many insect pests in garden areas. It feeds on whiteflies, aphids, scale insects, small caterpillars, spider mites, Colorado potato beetle larvae and many enemies of the gardener.

A parasitic insect that destroys pest larvae Source newogorod.ru

Encarzia is one of the most effective opponents of our pest. Belongs to the category of parasitic parasitic parasites, the larva of which pupates in the host's shell. About a week before planting the seedlings, place 3-4 bags of the parasite in the greenhouse. The females will independently find the whitefly and lay their embryos in its body, which will destroy their host.

Interesting! Common tansy planted in a greenhouse nearby provides good protection against whiteflies.

Yellow tansy is a gardener's friend Source fs3.fotoload.ru

How to make an effective trap?

You can make such a cunning trap - it is unexpectedly very effective:

• Step 1. Paint the pieces of plastic orange-yellow.
• Step 2. Next we cover them with entomological glue.
• Step 3. We attach the lighting directly to the plastic, which we hang at the level of the tops of the plants.

In just an hour, up to 80% of all parasites will stick there. And at night, set a second trap:

• Step 1. We drill holes in the box at the level of the light bulb - and we place it inside the box.
• Step 2. We also paint the light bulb orange-yellow.
• Step 3. Under the light bulb, at the bottom of the box, place a container of water.

The principle of operation of the trap is as follows: whiteflies strive for this light at night, get inside the box, fly, get burned on the light bulb and fall into a container of water. They don't know how to swim.

Reasons for appearance

This pest is attracted to high humidity and elevated temperatures. For this reason, whitefly is a frequent visitor to greenhouses. The whitefly feels comfortable in the greenhouse at any time of the year. At a temperature of -10 degrees, this pest dies, but the eggs do not die and can remain in this state for a long time, waiting for comfortable conditions.

Insects thrive in greenhouses where there is poor ventilation and where plants are located close to each other. Improper planting of plants leads to stagnation of moisture and active reproduction of the pest.

Advantages and disadvantages of insecticides

Advantages:

• A large selection of drugs on the market at different prices and different mechanisms of action on pests;
• Most chemicals effectively destroy both adult pests and their offspring;
• Some preparations have fumigator properties, that is, they form a protective cloud around the plant.

Flaws:

• Some chemicals can cause serious harm to the natural enemies of whiteflies;
• When using agrochemicals, you must follow safety rules and wear a mask, goggles and gloves;
• Some insecticides are quite expensive.

Folk remedies for whitefly

When wondering how to treat plants against whiteflies, do not forget about the folk remedies that have been widely used by summer residents for many years. The only thing that needs to be taken into account is that folk recipes will come in handy if there are not too many insects yet. Otherwise, using “store-bought” drugs will be more effective.

Sugar solution

Dissolve 2 tbsp. sugar in 1 glass of water and treat plants that show signs of whitefly damage. If it doesn’t help, repeat spraying with the solution after a week. After 5-7 days, spray the leaves with clean water to wash off the sugar film.

Garlic infusion

Chop 15 g of garlic cloves and add 100 ml of water. Cover with a lid and leave for 5 days. The infusion will be very concentrated, so to treat plants it is enough to dilute 5-6 g of infusion in 1 liter of water.

Grouping of drugs by composition

The use of insecticides is one of the main ways to protect crops from whiteflies. They all differ depending on the composition and active ingredient used.

1) Imidacloprid (“Confidelin”, “Confidor”, “Tanrek”, “Biotlin”, “Golden Spark”, “Monsoon”, “Imidor”, “Bison”, etc.);

2) Aversectin, avertin, abamectin or on another biological basis (“Fitoverm”, “Vertimek”, “Unitar”, “Farmacin”, “Iskra-Bio”, “Aktofit”, etc.);

3) Thiamethoxam (“Aktara”, “Cruiser”, “Tiara”, etc.);

4) Pirimiphos-methyl and other d/v from the FOS group (“Actellik”, etc.);

5) Permethrin / cypermethrin (“Alatar”, “Iskra-Double/Triple Effect”, etc.);

6) Malathion (“Fufanon”, “Alatar”, etc.).

It should be noted that almost all of the drugs listed below are very good and effective. The main thing is to strictly follow the instructions and observe safety measures when processing plants, since the toxic substances included in the composition are harmful to humans.

"Aktar". Treatment with this substance helps remove whiteflies for a period of up to 1 month. Treatment is repeated 3 times every 7 days to destroy midges in all life cycles of development. Vegetables can be eaten only after 60 days after the last application of the drug "Aktar". 1 sachet, containing 4 g, is diluted in 5 liters of water. This is enough for a large greenhouse area. To destroy, spray and water at the root.

"Aplaud." Can be used both in greenhouses and in open ground. Japanese insecticide allows you to get rid of insects for 1 month. Diluted 0.5 kg per 1 ha. To process 1 hectare you will need 1500 liters of water.

"Confidor". The drug is quite effective, so one treatment is enough. After an hour, the midges begin to die.

"Iskra Golden" These are tablets that easily dissolve in water. Also available in the form of ampoules, powder and sticks. A solution of 2 ml per 10 liters of water is prepared and sprayed on the plants. 1 or 2 treatments with Iskra Zolotoy are enough.

"Tanrek". A very effective and low-toxic substance that practically does not accumulate in fruits. To spray vegetables and indoor plants, you need to take 5 ml of the drug per 10 liters of water, for trees and bushes, 3 ml. Safety precautions must be observed when working with Tanrek, so be sure to wear respirators or face masks.

• Karbofos;
• Dichlorvos;
• Aktara;
• Commander.

A time-tested and effective drug is Karbofos for whiteflies. It should be used, like other chemicals, in strict accordance with the instructions. The first step is to take care of your protection - wear special clothing, protect your respiratory organs and eyes. The drug is dissolved in a ratio of 10 ml of substance per 10 liters of water.

The well-known Dichlorvos can be used against whiteflies in a greenhouse, but with caution. It is used in beds with tomatoes and cucumbers, and mainly as a preventive measure.

But for greens and herbs the use is strictly prohibited. The aerosol is sprayed before planting seedlings to prevent infection. Then the treatment is repeated twice at intervals of two weeks. More frequent spraying will lead to the development of immunity in the pest.

Aktara against whiteflies is an effective drug. The active substance in it is thiamethoxam. The poison penetrates the sap of plants that the moths feed on, which causes their death. You can spray plants with Aktara, or you can water:

1. To prepare a solution for spraying, a sachet of the drug (4 g) is dissolved in 5 liters of water. This amount is enough for about 5 square meters. m. or 125-150 plants. There is no need to wash off the drug.
2. For irrigation, make a less concentrated solution. 1 g of the substance is dissolved in 10 liters of water. Water with insecticide 2-4 times with an interval of 10 days.

An effective systemic insecticide - Commander for whiteflies; in a greenhouse you can spray it on tomatoes and cucumbers, or you can water it. When spraying, prepare a solution in the proportion of 5 ml of the drug per 10 liters of water. This amount is enough for 50-100 sq. m. Water with a less concentrated solution - 5 ml per 20-25 liters of water.

How to recognize a pest

Whitefly is most dangerous for crops with loose tissues:

• cucumbers;
• tomatoes;
• zucchini.

About 150 species of plants are attacked by this insect, while some species of butterflies prefer to lay eggs and live on certain crops.

Signs of parasite infection:

• Tiny whitish flies (imago) fly over the tops of plants;
• yellowish sticky spots with blurred boundaries are visible on the underside of the leaf blades;
• white spots on leaves (whitefly eggs);
• sooty dark coating;
• drying and curling of leaves, stopping plants from growing.

Without taking prompt treatment measures, the leaves become deformed, the buds and flowers fall off, and the ovaries are missing. At the same time, due to the sooty fungus that clogs the pores, the process of photosynthesis is disrupted. Infections appear in greenhouse plantings, and plants die before our eyes.