Last updated on October 23rd, 2023 at 08:19 pm
The spider mite, like aphids, reproduces very quickly and can cause severe damage in a short time. In today’s article we will see what damage spider mites cause on tomatoes and other vegetables, as well as the keys to prevent and eliminate spider mites at home with ecological remedies.
First of all, you must be attentive to intercept the spider mite in your orchard and, if present, fight with all possible means to eliminate the mites from the plants.
Contents
What is the red spider mite?
The spider mite (Tetranychus sp.) is a very small mite, less than 1 mm. Because of its small size it can only be differentiated well with a magnifying glass. If it is present in your crops, you can find it in the soil (where they lay their eggs and also hibernate) or forming colonies on the underside of leaves, where it lives feeding on the sap it sucks from them.
What crops does the spider mite attack?
Tetranychus sp. is one of the most common orchard pests because it is very polyphagous. That is, it can affect almost all garden crops: eggplant, squash, pea, lettuce, melon, potato, bell pepper, cucumber, bean, strawberry, corn… and also ornamental plants such as roses or chrysanthemums.
How does spider mite affect plants? Symptoms and damage
Its sucking mouthparts cause whitish or yellowish discolorations or spots on leaves. These spots occur around the points where spider mites suck sap.
In addition, the spots may enlarge, dry out and cause the entire leaf to dry and detach. As a result of this leaf damage, the plant’s photosynthesis is reduced. The plant can become very weak, reducing the quality and quantity of the harvest. This pest is very common in tomato crops.
The underside of leaves may be covered with a silky, web-like tissue where the mites live and move around. Also, spider mite colonies can sometimes cause small bumps on the upper surface.
In addition to this more “visible” damage, spider mites can also transmit viruses if they have been in contact with diseased plants before.
Prevention of red spider mite
Eliminating the remains of crops from previous harvests, especially if they have had red spider mites, and controlling weeds so that these mites do not stay near where our crops will be are two very appropriate preventive measures.
Fertilizing sufficiently and with a quality fertilizer, such as compost, will favor the natural resistance of the plants in your garden to pests and diseases.
Mites prefer warm, dry conditions, so moisture can adversely affect them and help reduce colonies. Spray the underside of the leaves with water if you have signs of them arriving in your garden or to prevent them from getting comfortable and staying on the leaves.
Also as a preventative method you can spray the underside of the leaves with Horsetail preparation, nettle infusion or other mite remedies discussed below.
How to eliminate spider mite infestation with ecological remedies
The first thing to do is to remove diseased parts of the plant, such as dried leaves that will no longer recover. Then combine some of the following home remedies to eliminate pests so that a good “integrated control” will kill the spider mite infestation.
Natural preparations to eliminate spider mite
These are some of the home remedies to combat spider mites:
Fern infusion
Nettle slurry.
Garlic insecticide. There are several options to make a garlic insecticide. I explain some of the possible preparations:
- Garlic macerate: Macerate for one night some peeled and chopped garlic cloves (about 100 grams) in a couple of tablespoons of oil. Then mix with 1 liter of water and spray on the underside of the leaves diluted to 5% (half a part of garlic solution per ten of water).
- Alcoholic garlic broth: beat four or five cloves of garlic together with half a liter of alcohol and half a liter of water. Then strain the mixture and keep it in a covered jar or flask in the refrigerator. When applying, dilute and spray on affected crops.
How to eliminate spider mite infestation with organic insecticides
There are several types of organic spider mite remedies that can be purchased and, although they do not come from plants, they are natural insecticides used on organic crops.
Examples of organic spider mite remedies:
- Pyrethrum
- Potash soap
- Kerosene oil.
- Neem oil
- Sulfur (spraying with sulfur-containing products or using wettable sulfur is an effective remedy to fight spider mites such as spider mites).
Be careful with these products and take a series of precautions for the application of oils and other organic spider mite insecticides.
Just because they are organic does not mean that they cannot be toxic, so be cautious. These spider mite remedies should not be applied in full sunlight and are not compatible with the application of sulfur, so you should leave a few days between both treatments.
You can find more information on these and other remedies to eliminate spider mite infestations in the article on natural insecticides.
Natural enemies of spider mites
There are several mites that feed on this pest and that can be very useful in eliminating spider mites from plants through “biological control or biological control”.
In this case you cannot capture them as you could do with ladybugs or other larger natural enemies, but there are commercial products that contain thousands of predatory mites in their composition that you can purchase from companies dedicated to biological pest control. The most used and effective are products with mites:
- Amblyseius cucumerisno
- Amblyseius californicus or Neoseiulus californicus
- Phytoseulus persimilis
There is also a mosquito that feeds on spider mites: Feltiella acarisuga, which quickly detects populations of this pest in the orchard, and settles where there are populations of spider mites. As larvae, this mosquito feeds on spider mite eggs, nymphs and adults, and can eat up to 30 individuals per day.