How to control armyworm in Northeast China?

How to control armyworm in Northeast China? Please introduce that the source of armyworm in Northeast China is mainly from the Yangtze-Huaihe River Basin. After the emergence of the first generation of adults in this area, it usually migrates into Northeast China from late May to mid-June to lay eggs, the second generation larvae appear in the field in the first and second ten days of June, most of the larvae enter the third instar stage in mid-late June, and the larvae continue to pupate from early to late July. The second generation adults continue to reproduce locally. Most of them moved southward back to the Yangtze-Huaihe River Basin and became the source of exotic insects in this area. The peak period of the third generation larvae in the local area is from late July to the first and middle of August, which can cause harm to millet and corn in some years. From late August to the first and middle of September, most of the adults moved southward, while a few stranded ones could not form harmful generations. Therefore, from the point of view of the whole country, the northeast region is the frequent area of the second generation armyworm and the occasional area of the third generation armyworm, and the main harm is the second generation armyworm. The first level of occurrence degree: light occurrence, 5-10 larvae per 10 plants in the corn field. Second class: moderate occurrence, 10-50 larvae per 10 plants in the cornfield. Grade 3: great occurrence, with more than 50 larvae per 10 plants in the cornfield. Prevention and control measures 1. Collect and induce eggs. During the oviposition period of adults, according to the oviposition characteristics of adults, continuous egg induction or removal of egg blocks in the field can significantly reduce the number of eggs and larvae. This method is effective for sparsely planted crops such as corn and sorghum. The method of egg induction is to cut the grain straw (or rice straw) into 50 cm long, tie into a handful every 3 roots, insert a handful every 20 steps, and insert 40-50 handfuls per hectare (when the number of moths is large, insert more as appropriate). 2. Artificial killing and weeding to kill larvae. During the larval occurrence period, weeds and larvae can be turned under the soil by mid-tillage, killing the larvae, reducing the humidity in the field and increasing the larval mortality. 3. Chemical control. According to the forecast, strict control of the appropriate period of control, early control, because there are still a considerable number of eggs in the field have not hatched, the following crops will still suffer. The control is late, the loss has been caused, the drug resistance of the older larvae is strong, and the control effect is not good. Generally speaking, the best period of pesticide application is that most of the larvae are in the third instar (mid-late June). Insecticides can be used either as general contact insecticides or stomach poisons, and pyrethroids or pyrethroids and organophosphorus mixtures have the best effect. The commonly used medicament and dosage per mu are: 2.5% enemy killing 30 ml; 5% Laifuling 20 ml; 24% killing 40 ml; 30% killing bell light 50 ml; 25% fast gram 20-30 ml; 25% Kuaishaling 20-30 ml; 5% cypermethrin 40 ml, etc., spray volume 15-20 liters per mu. It is best to use a motorized knapsack sprayer. Due to the large number of second-generation armyworm outbreaks this year, in view of the strong timeliness of armyworm prevention and control, while vigorously promoting the above lights and sex attractants to trap adults and reduce the number of eggs in the field, 45% chlorpyrifos EC can be used per mu. Or 25% chlorpyrifos EC 30ml 40ml, or 50% phoxim EC 10ml 15ml Or 2.5% cyhalothrin EC 15ml spray 30kg of water, the appropriate spraying time is before 9: 00 a.m. and after 5: 00 p.m. Click to get more pesticide application techniques