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Current Situation Of Second And Three Generations Of Helicoverpa Armigera In Xinjiang

2010/8/26 8:34:00 59

This year

Xinjiang

The occurrence of cotton bollworm in the autonomous region occurred late, and the two generation occurred moderately in cotton fields, which was similar to that in other years. It was lighter than that in 2008 and 2009.

The three generation took place 5-10 days later than last year.

At present, the cotton field in the northern Xinjiang is the three generation of the peak period of egg laying. The southern and eastern Xinjiang reach the beginning of the three generation of larval damage.

The three generation of Helicoverpa armigera mainly damaged the bolls in cotton fields, and had a great influence on the yield formation of autumn peach.

Monitor

Early-warning efforts aimed at local redevelopment of farmland, timely organization and effective prevention and control, reduce hazards.

The general situation of the first and second generations of cotton bollworm

The two generation of this year

Bollworm

In general, moderate occurrence occurred in some counties and cities in Changji Prefecture. The two generation larvae in Xinjiang cotton field occurred 2 million 330 thousand mu times, 12% less than last year, and the amount of eggs in corn, processing tomato and vegetable fields was relatively high, and the damage was relatively heavy.

From the end of June to the beginning of July, the first generation adults reached the peak of eclosion in the southern Xinjiang and eastern Xinjiang cotton growing areas. The average amount of single moth on the single day was about 30. In the early July, two generations of larvae began to harm in the cotton fields. In the middle and late 7 months, they entered the peak of damage, but most of the cotton fields were relatively less dangerous. For example, in Akesu, Akesu, the rate of harmful plants was 4.1%, the rate of killing the bolls was 0.6%, and the number of insects was 2.2.

The first generation of adults in the northern Xinjiang cotton region reached the peak of emergence in early July. The moth amount in Hutubi County of Changji Prefecture was relatively high. The average amount of single moth per day was about 100, while other areas were basically the same as last year. From late July to early August, the two generation of larvae in North Xinjiang entered the peak of damage. In Manasi County, Changji, the damage was more serious. The rate of damage to cotton bolls and fields was 8.9%, and the number of insect pests was 7.5, and the rate of local leaking prevention of fields was 66.6%.

Occurrence trend of two and third generation cotton bollworm

Based on the comprehensive analysis of the two generation of cotton bollworm occurrence, occurrence period, development progress and recent weather conditions, it is expected that the three generation will occur moderately in our region, and the area of cotton fields will expand, and some of them will be pferred to the multiple sowing corn.

Tacheng, Shawan County, Changji Manasi County, Hutubi county and Fukang City in Northern Xinjiang, Mengaiti County in Akesu, Ke Zhou and Kashi areas in southern Xinjiang will take place. The area is expected to reach 3 million acres, and the peak period will be from late August to early September.

Forecast basis:

The 1 and two generation of cotton bollworm adults caught the same amount last year.

1-10 days in August, Changji attracted 7 moths, less than the same period last year (21 in 2009); in Tacheng, Shawan County, 5-11 days in August, 52 moth moths were on the same level last year (48 in 2008); 9 in Yuli County on August 1-6 in Bazhou; 69 in August Akesu on August 1-11 in Akesu area, which was equal to that of the last year (68 68 head).

The 2 and three generations of cotton bollworm in the cotton field have low egg production and other crops such as maize Tian Piangao.

The average egg volume of cotton fields in Manasi County of Changji Prefecture is 1.1 grain / 100 plants. In Akesu area, there are 174 grain / 100 plants in the multiple cropping corn field in Akesu area, 47.7 grain / 100 plants (126.7 grains / 100 plants) last year, and 11.5 eggs per hundred cotton fields in Shawan County, Tacheng province. The average egg volume of the tomato field is 13 seeds per hundred plants; the average egg volume of the tomato fields in Bazhou Luntai county is 2 grains / 100 plants; and the average egg volume of 2 cotton plants in Ke Zhou is 100%, which is equal to that of the same period last year.

The occurrence period of the 3 and three generation is late than that of last year.

In August 10th, the damage rate of cotton fields in Akesu city was 1.83%, and the rate of damage was 0.25%. The average pest volume was 0.97 head / 100 plants, which was lower than that of last year in Akesu.

In Jiashi County of Kashi, there were 3 larvae per plant in August 2nd.

The average pest volume of tomato fields in Bohu county is 2.6 / 100 plants in Bazhou.

The rate of damaged cotton fields in PI Shan county of Hetian county is 4.2%, with an average worm volume of 2.8 head / 100 plants.

In the Shawan County of Tacheng on August 10-12, the average insect volume was 1.5 head / 100 plants, and the average insect yield in tomato field was 4.7 head / 100 plants.

In view of the characteristics of the three generation of cotton bollworm, such as irregular growth period, long occurrence period and serious overlapping of generations, all localities should continue to monitor closely, keep abreast of the dynamics of insect pests in local and surrounding areas, accurately release short-term forecasts, guide farmers to do scientific prevention and control, and ensure the safe production of cotton, corn and other crops.