Control methods for the third-generation cotton bollworm in cotton

1. Manual egg collection and pest elimination. Since most third-generation cotton bollworms are found in the flowers and bolls of insect-resistant cotton, for insect-resistant cotton fields, withered flowers should be removed promptly,    and pests eliminated manually. For other cotton fields, manual egg collection and pest elimination can be carried out along with pruning and removal of side branches, and the remaining branches and withered leaves should be taken out of the field for centralized disposal.

2. Seize the appropriate control period and apply pesticides scientifically.

1. For insect-resistant cotton fields, apply pesticides promptly when there are 10 larvae under the 3rd instar per 100 plants; for non-insect-resistant cotton and other crop fields, apply pesticides promptly when the cumulative number of eggs per 100 plants reaches 40 or there are 5 young larvae per 100 plants. Pesticide options include: (1) 140 ml of 40% profenofos emulsifiable concentrate per mu, diluted with 70 kg of water for spraying. (2) 50 ml of 2.5% lambda-cyhalothrin emulsifiable concentrate diluted with 70 kg of water for spraying.

2. For vegetable fields, when there are 20-30 eggs per 100 plants, 75 ml of 1% emamectin benzoate water-dispersible granules or 200-fold dilution of Bacillus thuringiensis preparation can be sprayed, or 2500-fold dilution of 1.8% abamectin or 5% flufenoxuron emulsifiable concentrate can be sprayed. The use of highly toxic, extremely toxic, or high-residue pesticides is strictly prohibited.

3. Precautions:

1. Because cotton plants are tall during the control period for third-generation cotton bollworm, spraying should be uniform and thorough, and the amount of spray liquid per mu should not be less than 70 kg.

2. Carry out good control of cotton bollworm outside cotton fields, and the use of highly toxic, extremely toxic, or high-residue pesticides on vegetables is strictly prohibited.

3. Choose spraying time before 10 a.m. or after 4 p.m. Spraying at noon is strictly prohibited to prevent pesticide poisoning.

4. Check the control effect promptly. If the control effect is poor after spraying or if rain occurs within 6 hours after spraying, respray promptly.