How many generations of Helicoverpa armigera occur in a year? How to prevent and cure? What kind of potion do you use?

Helicoverpa armigera, Lepidoptera and Noctuidae are widely distributed in China and around the world, and occur in cotton and vegetable growing areas in China. Cotton bollworm (Helicoverpa armigera) is an important boring pest in cotton bud and boll stage, which mainly eats buds, flowers, bolls and tender leaves. How many generations a year does the cotton bollworm produce? How to prevent and cure? What kind of potion do you use?

How many generations of cotton bollworm occur in a year?

The annual occurrence algebra and main damage generations of Helicoverpa armigera are different in different cotton areas of China. Three generations occur every year in the cotton area of the Liaohe River basin and most of the cotton areas in Xinjiang, and the second generation is the main damage in the cotton area of the Yellow River basin and part of the Yangtze River valley, and the second generation is the heaviest, followed by the third generation. The 3rd and 4th generations are the heaviest in most cotton areas of the Yangtze River basin, and 6-7 generations occur every year in the south of 25 °north latitude, and the 3rd, 4th and 5th generations are serious. All over the country generally overwintered as pupae in the soil.

How to control cotton bollworm? What kind of potion do you use?

At present, Helicoverpa armigera in northern Xinjiang has entered the peak egg hatching period, which will last until around June 5, and it is expected to cause harm in cotton fields in the form of first-generation larvae in early June, while southern Xinjiang is currently in a first-generation larval damage period. At the present stage, both southern and northern Xinjiang should focus on the prevention and control of the first generation of cotton bollworm.

Current suggestions on prevention and control of Helicoverpa armigera in northern Xinjiang:

(1) Northern Xinjiang: according to the simultaneous monitoring of light and sexual inducement, the overwintering generation of Helicoverpa armigera has entered the peak and final stage of adult Eclosion. According to the investigation of cotton field on May 22-23, the average egg number of the first generation is 3.9, and the highest egg number of 100 plants can reach 6.4. The number of moths attracted by sex is relatively large, and the maximum number of eggs in a single cage can reach 12. According to the analysis of meteorological factors, after heavy rainfall, with the increase of temperature, the growth of cotton seedlings is generally tender or prosperous, and the meteorological factor analysis predicts that the peak period of field damage of the first generation of Helicoverpa armigera larvae is in the first and middle of June. the occurrence degree was mild and moderate in some cotton fields.

Key points of control techniques for the first generation of cotton bollworm:

1. The choice of medicament:

The selection of biological pesticides such as Helicoverpa armigera polyhedrosis virus, methylvitamin salt and Bacillus thuringiensis is helpful to delay the drug resistance of insect pests and protect natural enemies.

2. Application time:

The main results are as follows: (1) the optimum period of application is at the peak of egg hatching and before the low instar larvae are bored. Spraying at the egg peak can effectively avoid the harm caused by cotton bollworm to crops. At this time, it is required to investigate frequently and master accurate forecast information.

(2) the application should be done after the dew dries out in the morning (8: 00, 30: 00, 10: 00) or after 18: 00 p.m.

3. Requirements for the quality of pesticide application:

Spray the middle and upper part of cotton evenly, using 30-40 liters of water (the water should not be too large) to ensure that the concentration of the solution is reasonable so as to improve the efficacy.

Suggestions on current plant protection work

1. Attach great importance to the monitoring and control of cotton bug bugs. Strengthen the investigation of cotton fields with prosperous growth and early budding, grasp the key period of prevention and control, apply pesticides in the evening, select a mixture of acetamiprid and avermectin, resolutely do a good job in joint prevention and control, and control the damage rate of cotton buds below 2%.

two。 In the prevention and control of cotton bollworm, it is necessary to make full use of green prevention and control methods such as sex traps to trap moths, and monitoring sites should do a good job in monitoring the whole process, effectively depressing the insect population and reducing the pressure of prevention and control.

3. For cotton spider mites, we should strengthen the investigation in and out of the field, take comprehensive control measures to control the number of insect sources to the minimum, and do a good job in monitoring and control cotton aphids. Yellow boards should be placed along the road at the monitoring point. When monitoring the migration of cotton aphids, yellow boards were placed in the cotton fields in order to reduce and postpone the damage of cotton aphids. For the early central plants of cotton aphids or cotton fields where small patches occurred, they should be marked in time to achieve spot control.