The peak of cotton bollworm migration occurred in North China of Huanghuai River

Release time: 2023-06-26

      According to the regional station of crop pest monitoring，Since June, the adult cotton bollworm has entered the blooming period，The number of attracting moths was higher in Huanghuai, North China and Northeast China，The meteorological conditions from late June to early July were favorable for the second generation of cotton bollworm in northern China，It is expected that the second generation of cotton bollworm will occur in most corn, peanut, soybean and vegetable crops in northern China this year，The trend of aggravating damage in local areas is obvious。The occurrence area of the country is 34 million mu, of which, the cotton field occurs in an area of about 4 million mu (Bt cotton field occurs lightly), and the other crop field occurs in an area of 30 million mu. The second generation larva damage peak period is in late June to early July。

      First, most of the adults in North China and Huanghuai are high in moth quantity

      Since June, a generation of adult cotton bollworm has entered the peak period, and the moth quantity in Huanghuai and North China is high, and the moth quantity in some areas is higher than the cumulative moth quantity in 2022 and 2021, and the cumulative moth quantity in some stations exceeds that in 2020, when the moth quantity is high。In Hebei, Shandong, Henan, Shanxi and other places, a total of 10 monitoring points have accumulated more than 1000 moths，Six of them had more than 10,000 units;Ground monitoring lights (black light) a total of 17 monitoring sites accumulated more than 1000 moths，Eight of the monitoring sites exceeded 3,000;The peak attractor days were concentrated in June 15-18，The number of peak moths is several hundred to several thousand，Some sites tens of thousands of head (data see the table below)。This time, moth peaks were concentrated at many points in the North China area of Huanghuai River, and the ground moth quantity was high in Henan Province and the upper air moth quantity was high in Hebei Province and Shandong Province. According to the preliminary trajectory analysis, it was speculated that the main migration was from the south of Huanghuai River to North China and the south northeast China。At present, sporadic larva has appeared in the fields in western Liaoning, and the hazard of larva outbreak after concentrated spawning should be vigilant。

      Moth attractants of adult cotton bollworm of first generation

      Second, the host crop layout is conducive to the occurrence and damage of cotton bollworm

      At present, the insect-resistant effect of Bt cotton in North China cotton area of Huanghuai River is stable，It played a certain role in controlling the occurrence of second generation cotton bollworm，However, due to the compression of Bt cotton planting area, the effect of trapping and killing was weakened，In Huanghuai, North China, Northeast China and other places, the planting area of corn, peanuts, soybeans, vegetables and other cotton bollworm favorite crops is large，And there are many compound planting modes such as intercropping，It provided sufficient feeding conditions for the breeding of the second generation of cotton bollworm。At present, summer corn and soybean are in the seedling stage in Huanghuai and North China, so it is necessary to be vigilant against the harm caused by the concentrated migration of cotton bollworm。

      Third, weather conditions are conducive to its occurrence

      According to the forecast of the National Climate Center, in July, there will be more precipitation in the central and eastern parts of Northeast China and northern parts of East China, while the precipitation in the central and western parts of Inner Mongolia, Beijing, northwestern Hebei, northern Shanxi, northern Shaanxi, northern Gansu, northern Ningxia and northeastern Xinjiang will be 1 ~ 2℃ higher, which is beneficial to the occurrence of cotton bollworm larvae。Less precipitation in western North China, central and western Inner Mongolia, northern and eastern Northwest China, and northeastern Xinjiang inhibited the occurrence of the larvae to some extent。

      In recent years, the population of cotton bollworm has increased significantly, and the second generation has entered the field of corn, peanut, soybean, vegetable and other crops outside the cotton field。All localities should pay attention to strengthen the investigation of each crop field, timely carry out scientific control of egg stage and young larva stage, and reduce the level of damage loss。

     (Source: Pest Control Office）