Control Methods for Red Spider Mites in Cotton Cultivation

Cotton leaf mite, also known as cotton red spider, fire dragon, fire spider. It belongs to the class Arachnida, order Acariformes, family Tetranychidae. The main species causing serious damage are the red leaf mite, Jiang leaf mite, and two-spotted spider mite. The individuals are small and highly reproductive, breeding more than 10 generations per year, and harm plants by piercing and sucking leaf sap with adult mites and nymphs. High temperature and drought are more suitable for its occurrence and damage. Integrated control techniques must be adopted to achieve effective control.

I. Damage Symptoms

Cotton leaf mites often gather on the underside of cotton leaves and spin silk webs, hiding their bodies under the webs while feeding on cotton leaf sap. When 1-2 mites are damaging the underside of a cotton leaf, yellow and white spots appear on the upper surface of the leaf. When 4-5 leaf mites are causing damage, small red spots appear on the cotton leaf. The leaf surface becomes reddish-brown and curled, as if scorched by fire. As adult mites multiply, the area of reddened cotton leaves gradually expands until the leaves wither and fall off. In severe cases, all leaves are completely defoliated, and it causes cotton buds and bolls to drop, affecting cotton yield and quality.

I. Agricultural Control Measures

1. Implementing autumn plowing and winter irrigation can greatly reduce the overwintering survival base of red spider mites and reduce damage in the following year.

2. Avoid intercropping or crop rotation of cotton with sesame, melons and other crops, increase potassium fertilizer application, promote healthy cotton growth, shape an ideal plant type, and reduce red spider mite damage.

3. Plant alfalfa at the field edges.

4. Water at appropriate times to increase field humidity, which can suppress the occurrence and damage of red spider mites.

5. Remove weeds at the field edges.

II. Biological Control

1. Protect and utilize natural enemies.

2. Use predatory mites to control pests with pests.

III. Scientifically and rationally apply chemical pesticides. When carrying out chemical control of red spider mites, professional acaricides should be selected. At the same time, note that the same pesticide variety should not be used every time; different types of acaricides should be used in rotation to avoid red spider mites developing resistance and making control difficult.