Tobacco cutworm
Also known as lotus moth, lotus moth
It is found in the pest noctuidae Prodenia litura (Fabricius), Lepidoptera, Noctuidae, distributed throughout the country.
The characteristic larvae feed on leaves, buds, flowers and fruits, and in severe cases, the whole field crop can be eaten. On cabbage and kale, it can be mothed into leaf bulbs and heart leaves, and excrete feces, causing pollution and decay, making it lose its commodity value.
The occurrence law occurs in 4 to 5 generations per year in North China, 5 to 6 generations in the Yangtze River Basin, and 6 to 9 generations in Fujian, which can breed all year round in Liangguang, Fujian and Taiwan, and there is no problem of overwintering. In the areas north of the Yangtze River Basin, the problem of overwintering has not yet been conclusive, and it is speculated that the spring insect source may have migrated from the south. Most of the Yangtze River Basin occurs in July and August, and in the Yellow River Basin, it occurs in August and September. Taking the 5-generation area of Zhejiang As an example, the peak period of l-generation larvae is from May 20 to the beginning of June, and the peak period of the 2nd generation larvae is from June 20 to the beginning of July, and the incidence of 1-2 generations is not heavy. There are two peak periods for the third generation of larvae, the first peak is in early July, and the second peak is in late July to early August, which is more severe. The 1st peak of the 4th generation of larvae is in mid-August, the 2nd peak period is from late August to early September, and the occurrence is large, the most serious damage, and the fifth generation occurs after mid-September, which is light. The Guizhou twill nocturnal moth is a more common pest in winter.
Prevention and control measures
(1) In summer, cruciferous vegetables such as Chinese cabbage can be covered with insect-proof nets throughout the whole process to greatly reduce the amount of insects.
(2) In the middle and lower reaches of the Yangtze River, Jiangsu, Zhejiang and the middle and lower reaches of the Yangtze River, focusing on prevention and treatment of 3 to 4 generations, and the appropriate period of prevention and treatment can be determined according to the field egg volume news
and the number of prevention and control times.
(3) Advocate the use of biopesticide 1 billion PIB/mL Alfalfa silver moth karyotype polyhedral virus 600-800 times liquid, which has high efficacy against 3-4 instar larvae. It can also be used with 24% methoxyhydrazide suspension 2500 times liquid, or 5% methamido avermectin benzoate emulsion 1000 times liquid, or 15% indicosyl suspension 2000 times liquid, or 5% lice mite urea emulsion 1000 times liquid.