Control of red spiders growing cotton

Cotton spider mite, also known as cotton red spider, fire dragon, fire spider. It belongs to Arachnida, Acarina, Tetranychidae. The main harmful mites are red spider mite, river spider mite and two-spotted spider mite. The individual is small, the fecundity is strong, and it propagates more than 10 generations a year. It is harmful to adults and nymphs to suck leaf sap. High temperature and drought are more suitable for its harm. Comprehensive control technology should be adopted in order to be effectively controlled.

I. harmful symptoms

Cotton leaf mites often cluster on the back of cotton leaves, spin silk and form a net, and hide the worms under the net to feed on the sap of cotton leaves. When two heads are damaged on the back of a cotton leaf, yellow and white spots appear on the front of the leaves. Small red spots appeared in cotton leaves when there were 5 mites infested by 4Mel. The leaves are curled in reddish brown, like fire. With the proliferation of adults, the area of red leaf cotton gradually expanded until the leaf charred fell off. In serious cases, all leaves are stripped, and cotton buds and bolls fall off, affecting cotton yield and quality.

I. Agricultural prevention and control measures

The main results are as follows: 1. The implementation of autumn and winter irrigation can greatly reduce the overwintering survival base of red spiders and reduce the harm of the second year.

2. Avoid intercropping or rotation of cotton with sesame, melon and other crops, increase the application of potassium fertilizer, promote the healthy growth of cotton, shape the ideal plant type, and reduce the harm of red spiders.

3. Plant alfalfa at the edge of the field.

4. Timely watering and increasing field humidity can restrain the occurrence and harm of red spiders.

5. Root out weeds on the edge of the field.

II. Biological control

1. Protect and utilize natural enemies.

2. Using predatory mites to control insects.

Third, the scientific and rational application of chemical pesticides in the chemical control of red spiders, professional acaricides should be selected. At the same time, pay attention to do not choose a variety of pesticides, to use different types of acaricide rotation, lest red spiders produce drug resistance and difficult to control.