Spider mite damage on plants: symptoms, prevention, and complete home remedies

  • The red spider is a highly damaging mite that thrives in dry, warm environments, attacking a wide variety of plants.
  • Its rapid reproductive cycle can decimate crops and ornamentals if it is not detected early and comprehensive measures are not adopted.
  • Ecological and biological control with predators and home remedies is effective in eradicating the pest and preventing new infestations.
red spider on plants

There are many pests that can threaten the health of our plants, but few are as dangerous and difficult to control as the Red spiderThis tiny mite, known scientifically as Tetranychus cinnabarinus o Tetranychus urticae, distinguished by its reddish color and incredible reproductive capacity. Although it's called a "spider," it actually belongs to the Tetranychidae family of phytophagous mites.

La Red spider It mainly attacks the young leaves and the shoots, weakening the plants with its sucking mouthparts, which extract sap and destroy plant cells. It is not usually visible to the naked eye because it is less than 0,5 mm in size, but the damage and symptoms it causes in plants become quickly evident if no action is taken in time.

Among the crops most affected by the Red spider These include basil, celery, zucchini, peas, green beans, melon, cucumber, watermelon, tomatoes, and carrots, as well as ornamental and fruit trees. From greenhouses to indoor and outdoor gardens, it is a real and widespread threat.

Red spider damage to rose bushes

What is the red spider and what is its biological cycle?

red mite on plants

La adult red spider It measures less than half a millimeter and has an oval, reddish body, although it can vary between greenish and orange hues depending on the season and species. It lacks wings and antennae, but has eight legs and a soft body. Due to their small size, they can go unnoticed until the infestation is serious.

Each female red spider mite is capable of laying between 5 and 20 eggs per day, accumulating between 100 and 200 eggs throughout her life, which hatch within a few days. Their full life cycle can be as short as 10 to 14 days in warm, dry conditions, meaning an infestation can multiply exponentially in a matter of weeks if no action is taken.

The eggs hatch and give rise to larvae They reach adulthood in less than two weeks after several molts. During this process, spider mite colonies rapidly expand to the lower, young parts of leaves, where they form colonies and protect themselves with fine silk webs.

red spider lily

Why does the red spider appear and where is it found?

La Red spider It is an opportunistic pest that thrives in dry climates and warm environments, since the moisture Low ambient temperatures (<50%) and high temperatures (>25ºC) favor their reproduction. Greenhouses, sunny terraces, and areas with little irrigation are the most affected areas.

They usually establish themselves first in weeds such as mallow and bindweed, which act as a reservoir. That is why it is It is essential to regularly remove weeds Around crops: If this initial focus is not controlled, the red spider can spread rapidly through wind, contact with tools, or handling of plant material.

The red spider is one of the most common pests in plants.
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red spider close-up

The young leaves And tender shoots are the spider mite's favorite habitat. However, in severe infestations, it can colonize any part of the plant. When its food source is exhausted, it spreads its webs and migrates to other plants. Spread by insects, animals, or humans is also possible, as well as through air currents and undisinfected tools.

How to recognize the symptoms and damage of red spider mites?

leaf damage caused by red spider

The first visible sign of infestation is the appearance of yellow dots or whitish spots on the upper surface of the leaves. These spots correspond to areas where the red spider has absorbed cell contents. As the infestation progresses, the leaves take on a dull, yellowish, or bronzed appearance, and eventually dry out and fall off.

  • Loss of color and vitalityThe red spider's feeding process prevents photosynthesis and depletes plant tissue of nutrients, causing yellowing, reddening, or necrosis of leaves.
  • Loss of turgorInfested leaves dry out prematurely and lose their firmness.
  • Discoloration and dwarfismEspecially in growing plants. The reduction in chlorophyll and plant fiber formation means that development and productivity are drastically reduced.
  • Fine cobwebsOne of the most striking symptoms is the formation of very fine cobwebs that cover the underside and, if the infestation is severe, can even envelop buds and flowers.

leaves affected by red spider

In fruit and vegetable crops, red spider damage also results in small, deformed, and lower-quality fruitsIn ornamental plants, leaf loss affects the aesthetics and even the survival of the plant.

Compared to other plagues, the enormous playback speed of the red spider and its resistance to a multitude of treatments requires action as soon as the first symptoms are detected. prevention and early detection is key to avoiding irreparable damage.

Effective methods of cultural prevention and control

best red spider insecticide

Prevention is the best ally against red spider mites. Keep appropriate cultural habits can significantly reduce the risk of infestation and improve plant recovery after an attack.

  • Control ambient humiditySpider mites thrive in dry environments. Regularly spraying water on foliage, especially during dry seasons or in greenhouses, helps keep the pest at bay.
  • Removal of weeds and plant debris: Weed control is essential, as weeds are often the first host before they move on to main crops. Remove and destroy affected plant debris.
  • Crop rotation: Alternate the type of crop each season to make it difficult for the pest to accumulate and reproduce continuously.
  • General maintenance: Use quality substrates, fertilize correctly avoiding excess nitrogen, and ensure good drainage and irrigation adapted to each species.
  • Cleaning tools and surfaces: Tools, gloves, and pots should be disinfected regularly to prevent the transmission of mites.
How to choose the best insecticide for spider mites
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Inspect plants regularly, especially on the underside of leaves, where they often nest and form webs. If you detect any abnormality, act immediately by isolating the affected plant to stop the spread.

Biological control of red spider mites: natural allies in the garden

ladybugs vs. red spider

El biologic control It is an ecological and sustainable strategy to combat the red spider, taking advantage of natural predators that keep their population under control without harming the environment or beneficial insects.

  • Predatory mites: Among the main natural enemies of the red spider are the mites of the genus Phytoseiulus persimilis, Amblyseius californicus, Neoseiulus californicus and Amblyseius andersoniThese feed on red spider eggs, larvae, and adults and can be purchased from stores specializing in biological control.
  • Lacewings and ladybugsThese insects also feed on mites and other phytophages, making them excellent helpers in crops and gardens.
  • Diptera CecidomyiidaeTheir larvae are voracious predators of mites. Adding flowers and shelters to the garden helps attract these allies.

It is important to avoid the indiscriminate use of chemical insecticides and acaricides, as they can eliminate these predators and disrupt the natural balance. The release of predatory mites should be done at the appropriate time, preferably at the onset of the infestation.

Guide to home and natural remedies to eliminate red spider mites

protect tomatoes from red spider

Numerous Homemade and natural methods To combat spider mites effectively and safely, both for plants and the environment. Below are the most effective and proven remedies:

1. Water spray

Red spider hates humiditySpray all leaves liberally with water, especially the undersides. This action displaces mites, increases ambient humidity, and limits their proliferation. It can be used as a preventative and curative measure.

  • Spray every other day for a week if you detect the infestation.
  • Avoid overwetting the substrate to prevent fungus.

2. Potassium soap or insecticidal soap

potassium soap against red spiders

El potassium soap It's an eco-friendly insecticide that weakens the mite's exoskeleton. Mix 5 to 10 ml of soap per liter of water and spray it on the plant, thoroughly covering the underside of the leaves. You can rub gently with a cloth to remove any residue. Repeat the process every 3-5 days.

  • Do not apply during hours of maximum sunlight to avoid damage to the leaves.
  • Useful for indoor and outdoor plants.

3. Garlic infusion

garlic has repellent and antifungal propertiesCrush 3-5 garlic cloves and let them soak in a liter of water for 24 hours. Spray on plants at night to prevent sunburn and do not rinse. Repeat every 3-4 days until the pest is eliminated.

4. Nettle infusion (Nettle slurry)

red spider nettle slurry

El nettle slurry It is one of the most used remedies in organic farming:

  • Boil a handful of fresh nettles in a liter of water.
  • Let it sit for 24 hours, strain, and use the liquid to pulverize the leaves.
  • In addition to repelling red spider mites, it strengthens plants due to its richness in minerals.

5. Horsetail decoction (Equisetum arvense)

Very effective both as a preventative and curative remedy. Use 20 grams of dried horsetail (or 150 grams if fresh) per liter of water. Let it steep for 12 hours, boil a third of the mixture for 20 minutes, and mix everything together. Spray every 10-15 days as a preventative measure or three days in a row during an infestation.

6. Flour preparation

Dilute two cups of fine white flour in five to ten liters of water. Spray the mixture on the leaves and let the sun evaporate the water. You can also mix one cup of buttermilk with eight cups of flour in 50 liters of water and apply to the underside. Repeat several times.

7. Neem oil and horticultural oils

El neem oil It's a natural and safe insecticide for plants that, when mixed with water (and optionally a few drops of neutral soap), is sprayed on all affected parts. Apply in the afternoon or evening and repeat every 5-7 days.

Horticultural oils (white, mineral, or canola oil) suffocate mites and prevent egg development. Mix one tablespoon of oil and one tablespoon of soap per liter of water. Spray when there is no direct sunlight.

  • Avoid combining oils with sulfur, as it can be toxic to the plant.
  • Paraffin oil, being less specific, can harm beneficial insects. Use it only when necessary and never during flowering.

8. Hot pepper infusions

La capsaicin Peppers are a powerful repellent. Boil 2-3 fresh peppers in a liter of water for 20 minutes, let cool, and strain. Spray every two days until the pest is controlled, wearing gloves and protective eyewear.

9. Extracts and essential oils of basil, mint or eucalyptus

Boil a handful of fresh leaves in water for 15 minutes, let it cool, and strain. Spray the leaves at night. Alternatively, add 10-15 drops of peppermint or eucalyptus essential oil to a liter of water and use as a weekly spray.

10. Sprinkle with sulfur

El micronized sulfur It is very effective but should be used with caution. Sprinkle a fine mist over the entire plant, thoroughly covering the underside and upper surfaces of the leaves. Do not use during flowering or in combination with oils or in crops with biological predators, as it can kill them.

red leaf spider

Additional recommendations and practical tips

  • Apply the home remedies repeatedly to ensure complete elimination of eggs and adults, as a single application is not sufficient to break the life cycle.
  • Avoid using the same products continuously: alternate treatments to avoid resistance.
  • Isolate infested plants and remove severely affected ones to prevent spread.
  • Keep a record of application dates and pest development.
  • Always spray during hours of lower solar radiation and never on very hot days.

How to choose the best insecticide for spider mites
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Red spider mite on plants: identification, prevention, and comprehensive control

Monitoring and early detection: the key to success

To keep the red spider under control, check periodically Examine the undersides of the leaves with a magnifying glass, looking for cobwebs, moving dots, or yellow spots. You can use yellow sticky traps as an additional monitoring method, as these mites can be attracted to the color.

The first signs of plant weakening should alert you, and you should immediately act with the most appropriate remedy for your case and depending on the degree of infestation.

Common mistakes when treating spider mites

Despite the effectiveness of natural remedies, there are some mistakes that can complicate the solution to the problem:

  • Disinfect only superficially and leave eggs on the leaves.
  • Applying products in full sun will burn the plant.
  • Neglecting to clean tools and facilities.
  • Using chemical pesticides indiscriminately, eliminating natural enemies.
  • Do not alternate treatments and encourage resistance in the pest.

protect tomatoes from red spiders


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