The Most Effective Methods for Controlling Red Spider Mites on Vegetables Include Pesticides and Natural Predators

Red spider mite, also known as cotton red spider mite, commonly called big spider, big dragon, sand dragon, etc., with the scientific name spider mite, is one of the pests in crop production, and its damage is very serious. So what are the most effective methods to kill red spider mites? What pesticide is most effective?

Damage characteristics

Red spider mites mainly damage the leaves, stems, flowers, roots, etc. of plants, sucking the sap from the stems and leaves, reducing the water content of the affected parts, causing loss of green color and whitening, with dense pale small spots appearing on the leaf surface, curling and yellowing. In severe cases, the plant develops yellow leaves, scorched leaves, curled leaves, leaf drop and death. In hot and dry weather, especially under consecutive sunny and hot days without rain, the disease is severe. The initial symptoms are loss of green color in the leaves, with the leaf margins curling upward, after which the leaves wither and fall off, causing the flower buds to shrink, and in severe cases the plant dies.

Living habits

If we want to kill red spider mites, we need to have a certain understanding of their living habits and grasp their weaknesses, so that we can kill them more effectively.

Red spider mites have a very strong reproductive capacity, and can occur 12~20 generations in 1 year, with 2 peak periods. The 1st peak is in April—May, and the 2nd is in September—October. Red spider mites tend to prefer tender green growth, and after new shoots grow out, the harmful mites on old leaves move to the new shoots. Because red spider mites reproduce rapidly under high-temperature and dry climate conditions, with a large reproduction coefficient and frequent generations, a single leaf can simultaneously have four forms: eggs, larvae, nymphs, and adults.

The most effective methods to kill red spider mites

Method 1, Chili pepper water method for treating red spider mites

This method is also relatively commonly used. When red spider mite disease appears on vegetables, water used to boil chili peppers can be sprayed to kill them. The effect is also very good.

Chili pepper liquid: mash 50 grams of fresh chili peppers (or dried chili peppers), add 20 times the amount of clean water, soak for 5-6 hours, then filter and spray on the plants. It can effectively control aphids, red spider mites, cutworms, etc.

But note that all these methods should be used in small amounts, not in excessive amounts, and should be done step by step. Spraying several more times will naturally clear the red spider mites completely. Being too impatient will instead be harmful to the vegetables. After bringing them under control, continue spraying several more times to consolidate the effect!

Method 2, Washing and bagging method

Directly lay the potted plant on its side (be careful not to spill the topsoil all over the ground), hold a water gun in one hand, and gently rub and wash the undersides of the leaves with the fingers of the other hand. Red spider mites are very easily crushed to death by rubbing.

After washing every leaf clean, cover the entire potted plant with a large garbage bag, and tie a rope below to retain moisture. Because red spider mites cannot tolerate high-humidity environments, this can create an environment they hate.

After covering for three days, wash with water once more, then cover again for three days. Based on practical experience, this can thoroughly solve red spider mites.

Method 3, Comprehensive milk spraying method

Milk made from milk powder is enough, and the concentration should be reduced by half compared with the general usage amount (dilute one to two times more).

Choose weather with relatively little wind and spray the whole plant with a sprayer in the morning and evening. The amount used should reach a moist state where there are milk droplets along the leaf edges, because red spider mites will suck the milk, and finally become bloated and die.

If there are not many vegetables at home and the red spider mite infection is not serious, the milk killing method is very effective and environmentally friendly.

If the number of plants is large and dense, and red spider mites break out, this method will not have much effect, because red spider mites will reproduce again after 7-10 days!

Method 4, you can also try the other three methods:

(1) Citrus peel liquid: soak citrus peel in about 10 times the amount of water for 1 day and night, then filter and spray on the plants. It can control aphids and red spider mites, and if poured on vegetables it can control nematodes in the soil.

(2) Washing powder and caustic soda liquid: 15 grams of washing powder, 15 g of 20% caustic soda, add 7.5 kg of water, mix evenly and spray. After 1~2 days, check, and the mortality rate of adult and larval red spider mites is 94%~98%.

(3) Sichuan pepper liquid: add 100 grams of Sichuan pepper to 1000 grams of clean water and boil it down to 500 grams of stock solution for later use. When applying, add 5-7 times the amount of water and spray on the plants. It can control aphids, red spider mites, whiteflies, etc.

Note: It is best to carry out pest-killing activities after 2 p.m., when red spider mites are basically all on the leaf surface, and the insect control effect is best.

Just like getting sick, if you usually do not pay attention to your health and do not do a good job of prevention and control, once you get sick, it is basically very difficult to cure it without injections, medicine, or surgery.

Therefore, it is necessary to do a good job of pest and disease prevention and control in ordinary times. Do not wait until the vegetables have reached late-stage cancer before thinking about prevention and control, because by then it is basically already too late.

Natural enemies of red spider mites

There are many kinds and quantities of its natural enemies, mainly including Stethorus punctillum, Stethorus siphonulus, Harmonia axyridis, large and small green lacewings, minute flower bugs, etc. They play a positive role in controlling pest population numbers.

Control methods

1. Water regularly. Because red spider mites like high-temperature and dry environmental conditions, when the field is dry, open holes and water in time to compensate for the plant's water loss and reduce red spider mite reproduction.

2. Red spider mites have two reproduction peaks. After March, pay attention to observation in ordinary times. When abnormal leaf color is found, carefully check the undersides of the leaves. When insect infestation occurs on relatively many leaves, spray pesticide as early as possible. You can choose 22% abamectin.spirodiclofen emulsifiable concentrate 3000-fold solution, or 25% abamectin.etoxazole emulsifiable concentrate 2500-fold solution and other pesticides for spray control. These pesticides have the characteristic of killing both eggs and larvae, with especially excellent egg-killing effect and a long lasting period. In production, the effective period reaches more than 30~40 days.