spider mite

Have you ever bought a beautiful indoor flower, which soon became covered with sticky cobwebs for no apparent reason and died? Or lose entire plantings of cucumbers, tomatoes or berries when their leaves suddenly begin to dry out and fall off? Most likely, a spider mite wound up on such plants.

Fighting this pest is difficult, but possible. And now we will tell you how to do it.

What does a spider mite look like in a photo

Spider mites are so small (usually less than 1 mm in length) that it is very difficult to see them with the naked eye. The maximum that a person will see on an infected plant is a very thin sticky web with mobile brown, dark green, yellow or red dots.

However, if you examine these points with a magnifying glass, you will see the classic representatives of the order of acarimorphic ticks. These arachnids (ticks are not insects!) have an oblong body and 8 legs. Spider mites have 4 eyes on their heads. The main feature that distinguishes these mites from other plant pests is the ability to isolate the web.

Most common common spider mite (Tetranychus urticae), found in more southern regions red fruit mite (Tetranychus cinnabarinus)(1).

Interesting facts about spider mites

What is dangerous spider mite

Spider mites can be called a real plant vampire. Already at the stage of a nymph (a young immature individual), he begins to feed on the juice of the plant on which he lives. With the help of the so-called stylet – a modified mouth apparatus, a nymph or an adult tick pierces a leaf of a plant and drinks all the juices, because of which the leaf is deprived of moisture, nutrients and chlorophyll (3). In addition, the saliva of the tick, getting into the plant, disrupts the metabolism, so that it can no longer withstand the onslaught of the pest. Dehydrated leaves dry up and fall off, and with a strong invasion, the plant dies.

Another danger that even a small lesion with a spider mite is fraught with is a decrease in immunity. Often such plants are affected by gray mold or viruses (4).

Signs of the appearance of a spider mite

The first signs are small whitish spots on the leaves of the plant. And often summer residents and flower growers do not pay attention to this – well, you never know why spots appeared on the leaves.

However, as the tick begins to multiply, the signs of infestation become more pronounced. And the main one is the thinnest sticky web, which gradually braids the entire plant. Greenish or brown dots are always visible on the web – in fact, ticks.

At first, the web appears on the lower parts of the plant on the back of the leaves, but gradually rises to young shoots. And now the whole bush or even a tree is standing in a sticky cocoon.

Summing up, we can distinguish several main signs of damage to plants by a spider mite:

• the leaves are covered with white dots and acquire a marble color;
• leaves dry en masse and fall off;
• the plant is covered with a sticky cobweb with moving dots of dark red, greenish or brown color.

Causes of the appearance of a spider mite

The spider mite spreads with the help of its web. It is very thin, light and sticky, making it easy to stick to anything that comes into contact with the affected plant. That is, you can bring the tick home or into the garden, even on your own hands or clothes.

Due to the fact that in the early stages of the lesion it is not always possible to identify the pest, people sometimes acquire infected planting material or indoor flowers. And once in favorable conditions, the mites begin to multiply intensively, and now the web has covered the entire garden, flower bed or window sill. Moreover, you are not immune from this, even if you buy a plant in a store.

The main ways of spreading the spider mite in the garden, garden or apartment:

• with objects, people or animals that have been in contact with infected plants (including bouquets of flowers);
• through contaminated soil;
• through infected plants and planting material.

The most active spider mite develops at low humidity and a temperature of about 30 ° C.

How to treat plants from spider mites in a greenhouse

Spider mites reproduce very quickly, so treatment should begin as soon as possible.

Folk methods

If you notice that the plants in your greenhouse are affected by spider mites, you can use natural and harmless remedies for both plants and people.

Onion infusion. Cut onion or onion peel and pour water at the rate of 100 g of onion per 5 liters of water. Insist for a week, then spray greenhouse plantings.

Infusion of garlic. Chop the peeled garlic cloves and pour water in the proportion of 2 cloves per 1 liter of water. Insist 5 days. Use for spraying.

Infusion of dandelion roots. Pour dandelion roots with warm water at the rate of 20 g of root per 1 liter of water. Insist for 2 hours, then spray the plants.

Red hot pepper. Mix 50 g of hot pepper in 500 liters of water and spray the leaves with this solution.

Apple vinegar. The solution is prepared at the rate of 30 ml of vinegar per 10 liters of water. Also used for spraying.

Soda ash. Dissolve 50 ml of soda in 10 liters of water, then spray the plants with this composition. This is one of the most effective folk methods of dealing with spider mites in a greenhouse.

Hydrogen peroxide. Also an effective folk method. It is necessary to dissolve 20 ml of 3% peroxide in 1 liter of water. Spray plants.

“But it’s important to remember: folk remedies help against spider mites only as a preventive measure and at the initial stage, if the tick is still a little bit,” says Candidate of Biological Sciences Irina Zilbervarg. – And, of course, it is better to use folk remedies if the plant is indoors, especially where there are children and animals.

Preparations

Today on sale you can find many chemicals that help to successfully cope with the spider mite in a greenhouse.

Fitoverm. This drug is recommended for the control of spider mites on cucumbers, tomatoes, peppers and eggplants in protected ground. The drug is diluted at the rate of 0,04 ml per 1 liter of water. 3 – 4 treatments are required with an interval of 20 days. Consumption – 1 – 3 liters per 10 square meters. m (5).

Antiklesh. Recommended for cucumbers and tomatoes – 10 ml of the drug per 10 liters of water. Consumption rate -3 – 5 liters per 10 square meters. m (5).

How to treat plants from spider mites in the open field

In principle, the fight against spider mites in the open field differs little from that in the greenhouse, so most of the methods will be the same. Unless in the open air it is much more difficult to maintain a high level of humidity, which is detrimental to the pest, and certainly not to lower the air temperature in hot summer.

Folk methods

In open ground, you can use the same folk remedies as in the greenhouse.

But it is important to remember: solutions and infusions need time to work. Therefore, the treatment of plants from spider mites should be carried out on a clear day. And it is desirable that there will be a couple more sunny days. If it rains, all the protection will wash off and there will be no sense.

Preparations

In the event that the infection has gone far enough, folk methods will no longer save your crop. You will have to resort to proven and effective chemicals. Moreover, the treatment should not be done once, but repeated several times at intervals of a week or 10 days (some drugs have a longer pause).

Tiovit Jet. Recommended for processing grapes during the growing season. The drug is diluted at the rate of 30 – 40 g per 10 liters of water. Consumption rate – 10 liters per 100 square meters. m (5).

Apollo. Most effective for processing apple trees and grapes. The drug is diluted at the rate of 4 ml per 10 liters of water. The consumption rate is from 2 to 5 liters of solution, depending on the size of the tree (for an apple tree), the growth and the method of forming a bush (for grapes) (5).

Antiklesh. Recommended for spraying raspberries and apple trees – 10 ml of the drug per 10 liters of water. Consumption rate – 2 liters per 10 raspberry bushes (processing can be carried out before flowering and after harvesting) and 2 – 5 liters per apple tree, depending on the age of the tree (you can process throughout the season, but no later than 20 days before harvest) (5).

Prevention from infection with spider mites

Spider mites are very fond of settling on plants that are fed with nitrogen fertilizers, but phosphorus ones, on the contrary, disdain. In addition, their ideal habitat is dry heat. So, if you want to minimize the chance of infection, give up nitrogen for a while and add phosphorus to the soil, and spray your plants more often. In addition, it is worth lowering the temperature in the greenhouse a little and ventilating it more often – the tick will not like it either.

In general, recommendations for the prevention of spider mite infection look like this:

• well ventilate greenhouses;
• Quarantine purchased seedlings or indoor flowers for some time to make sure they are not infected;
• maintain a sufficient level of humidity – spray the plants with a spray bottle (this applies primarily to indoor plants).

Popular questions and answers

We talked about the fight against spider mites with candidate of agricultural Sciences Denis Kostylev and Candidate of Biological Sciences Irina Zilbervarg.

Sources of

1. Rekk G. F. Key to tetranych mites // Tbilisi: Izd. Academy of Sciences of the Georgian SSR, 1959 – 151 p.
2. Mitrofanov V.I., Strunkova Z.I., Livshits I.Z. Determinant of the tetranych tick fauna of the USSR and neighboring countries (Tetranychidae, Bryobiidae) (under the editorship of V. G. Babaeva). Gos. Nikita. butane. Garden, Institute of Zoology and Parasitology. E. N. Pavlovsk Academy of Sciences of the Tajik SSR // Dushanbe, Donish, 1987 – 223 p.
3. Bagdasaryan A.T. Fauna of the Armenian SSR. Tetranychoid mites (superfamily Tetranychoidea) // Yerevan, Ed. Academy of Sciences of the Armenian SSR, 1957 – 163 p.
4. Zeynalov A.S. Bioecological features and harmfulness of the common spider mite (Tetranychus Urticae (Koch.)) on garden strawberries in the Orenburg region // Orenburg State Agrarian University, Orenburg.
5. 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/