Prevention And Control Of Cotton Bollworm Outbreak In Northern Xinjiang

Affected by continuous high temperature and drought weather and planting this year, the two generation of Helicoverpa armigera occurred in the northern part of Xinjiang. Local outbreak occurred in the southern part of Xinjiang and most parts of the eastern Xinjiang. The development period of Helicoverpa armigera in the northern Xinjiang was obviously shortened, and the occurrence period was obviously earlier than that in the southern Xinjiang.

At present, most cotton regions in the southern Xinjiang are at the end of pupal stage of the two generation of Helicoverpa armigera larvae. The peak period of the three generation of Helicoverpa armigera, the peak period of oviposition, the peak of hatching and the beginning of the larval stage in the northern Xinjiang are overlapping generations.

1. Current occurrence of Helicoverpa armigera

The number of moths is more than that: according to Bole City, bole, July 23rd, there were 53 moths (45 females and 8 males), and 57 moth heads (31 males and 26 females) on 26 days, and 45 (female 33 heads and male heads) and female heads (male and female heads) on 27 and 28 days in Jinghe county.

In the Shawan County of Tacheng Province in July 23rd, there were 86 female moths and 14 male moths.

The amount of moths is 2 times more than that of last year.

The eggs were on the high side: according to the census of 28 and 29 July in Bole, Northern Xinjiang, the rate of egg field was 100%, the average egg volume of 17.6 plants was 100, and the number of eggs in 10-19 fields was about 50%. The number of fields with 20--30 eggs was 20%, and the number of eggs with more than 31 eggs was 2%.

In Changji, Changji, in July 27th, the three generation had entered the period of spawning, with an average of 84.6 eggs per plant. Among them, the average amount of eggs per plant in the lower spring village was 280, and the average egg volume of 550 species was 550, and the average number of eggs was 310.

On July 25th -28, Shawan County in Tacheng province monitored that there were 44.5 cotton bollworm eggs on average in the cotton field. There were 48.5 bollworm eggs in the tomato field, and 18 bollworm eggs on average.

There are many larvae: according to the census of 28 and 29 July in Bole, Northern Xinjiang, 1-4 instar larvae were found in cotton fields, 3 to 23 insects in one hundred plants, 80% in the 1 instar hatched, and 5 16.1 70 in the 100 plants.

In the Shawan County of Tacheng, on July 25th -28, the average number of larvae was 3.5 (1-3 years) in the cotton field. There were 8.5 larvae in the tomato field, and 3 in Capsicum.

昌吉州7月21-23日監測，棉田平均蛀蕾鈴率25.64%，加工番茄平均蛀果率34.7%，其中昌吉市、阜康市、吉木薩爾縣局部棉田嚴重危害蛀蕾鈴率72-80%，昌吉市局部棉田蛀蕾鈴率22-60%，加工番茄平均蛀果率11.8%；阜康市棉田平均蛀蕾鈴率60%，危害嚴重的棉田蛀蕾鈴率高達86%，加工番茄蛀果率18-80%，百株幼蟲6-40頭，有蟲田率100%，玉米田平均百株幼蟲62頭，最高點百株幼蟲平均132頭，玉米花絲平均為害率為53.7%；瑪納斯縣平均蛀蕾鈴率0.08%，發生較重的棉田蛀蕾鈴率21.25%，晚熟加工番茄田蛀果率達20%；呼圖壁縣棉田蛀蕾鈴率11-13%；吉木薩爾縣局部棉田百株幼蟲109頭，被害株率80%。

Two, late trend analysis

At present, the amount and amount of eggs in the cotton fields in Northern Xinjiang are still high. It is expected that the three generation of Helicoverpa armigera will continue to aggravate the danger. The three generation of Helicoverpa armigera will take place in the northern Xinjiang. The harming period of cotton bollworm larvae in cotton fields is in early August, and the peak period is 8 mid late.

Climatic factors: after entering May, the temperature continues to be exceptionally high. The drought in Xinjiang in 2008 is second only to 1974. It is the second severe drought year since meteorological records. The average temperature is high, breaking through the extreme value of the same period of history. The high degree is 50 years. At present, the drought situation in Northern Xinjiang and other places is still very severe, which is very conducive to the occurrence of Helicoverpa armigera.

Factors of crop layout: industrial restructuring, crop diversification, growing area of processed tomatoes, vegetables and corn, providing a rich source of food for cotton bollworms.

Cardinal factors: early spring in the northern Xinjiang, premature growth of cotton, high pupation rate, low mortality rate, high number of insect base and high number of pests in the second generation of cotton bollworm caused the three generation of cotton bollworm to continue to erupt.

Three, current work priorities

Faced with the serious situation of insect pests in cotton fields at present, plant protection departments at all levels should enhance the sense of responsibility of technicians, strictly control technology, pay close attention to the occurrence and development of pests and diseases, do well in monitoring pests and diseases, grasp the dynamics of insect pests in time, strictly implement regular reporting system, and report the same number of outbreaks and outbreaks of pests and diseases on the same day by telephone and e-mail.

According to the actual situation of pests and diseases, report to the local government and relevant departments in time, provide basis for the government's prevention and control decisions, grasp the appropriate period of prevention and control, do well in the prevention and control of pests, and improve the control effect of pests.