Adult thrips and nymphs use file-sucking mouthparts to feed on heart leaves, buds, young leaves, floral organs and young juices, so that the heart leaves of the injured plant cannot expand normally, and the tender shoots and tender leaf curled tissues harden and shrink, and clusters appear. phenomenon. The hair turns grayish brown or dark brown, and the plant grows slowly and the internodes are shortened. After the young fruit is injured, the abnormal growth of the fruit is slow. It is damaged when it is bigger, the skin of the fruit is rough, and there are dark brown spots, and when it is severe, it will cause fruit drop.
The difficulty of preventing and controlling thrips is related to the characteristics of thrips, and control measures should be taken around the characteristics of thrips.
1. Increase humidity to kill insects.
Thrips go through three stages of eggs, nymphs (pupas), and adults throughout their lives. The adults lay their eggs in tissues such as growth points, tender leaves, flowers and so on. The hatched nymphs will pupate in the middle ages at 2nd instar, and then emerge as adults. Since the laid eggs are relatively hidden and protected by a layer of shell outside, it is generally not easy to kill, so the best deal is this period when it burrows into the soil and pupates. When thrips pupate in the soil, if the soil water content is small and the soil temperature is higher, it is very conducive to the hatching of thrips. Therefore, you can often run small water and spray clear water to increase the humidity of the soil and the air, which will help reduce the hatching rate of thrips, inhibit the growth of nymphs, and always control the thrips within a certain range.
2. Adjust the spraying time.
Thrips are afraid of light and have the habit of being nocturnal. As the light intensity increases, the thrips that damage the leaves will hide in the flowers or in the crevices of the soil. This is one of the reasons why thrips are difficult to control. When using conventional contact agents, because of its characteristics, no insects can be sprayed during the day and no efficacy can be seen. The spraying time is best to choose early in the morning when the dew is not dry or near the evening, when the thrips begin to move on the surface of the crop, and the liquid is easy to spray.
3. Spray evenly.
Adult thrips are good at flying and are afraid of light, and often damage the leaves or young shoots. When spraying, focus on the new leaves and other parts of the wine sheath. Therefore, when applying the medicine, not only the leaf surface and the back of the leaf should be sprayed evenly, but also the ground should be sprayed to kill the thrips pupae hidden in the soil.
4. Alternate medication.
In recent years, the former horses have become increasingly resistant to existing pesticides, and attention should be paid to strengthening the rotation of medication. At present, the commonly used agents for the prevention and treatment of thrips are ethoxylate (Ivy) bifenthrin, acetamiprid, imidacloprid and other agents, and ethyl oxychloride (Ivy), bifenthrin contact kill It has good properties, acetamiprid and imidacloprid have good systemic properties. These two types of agents can be used together and pay attention to alternate medications. The organic silicon synergist is added to the liquid medicine to enhance the permeability of the medicine.
Post time: Jun-03-2021