Onion growers recently concentrated on reflecting, onions suddenly recruited a lot of green bugs, nibbling on the leaves, resulting in a decrease in yield and commerciality, bringing greater losses to growers, the most headache is very difficult to treat, even once a day medicine, insects or not less, which can be sad for onion farmers, for this small editor urgently wrote this article, hoping to help growers.
The world's most difficult beet moth, Hengshuijing County cotton, peppers have happened, see what they do
Many people mistakenly think that this insect is a vegetable green worm, but in fact, it is a beet nocturnal moth. Beet noctuidae is an omnivorous pest, which can cause serious harm to more than 170 crops such as onions, kale, sweet potatoes, cotton, peppers, soybeans, etc. The insect is a pest that occurs intermittently, and the occurrence varies greatly from year to year. General production is reduced by 20%, and severe as high as 50%.
Symptoms of beet nocturnal moths harming onions
The number of generations that occur every year of the beet moth gradually increases from north to south, occurring 5 generations per year in our Shandong province to pupate overwinter in the topsoil layer. Overwintering adults begin in mid-June of the following year, the first generation of larvae occurs in late June to early July, the second generation of larvae occurs in late July to early August, the third, fourth and fifth generations occur in August to October, with different generations, and the fifth generation of larvae pupate in mid-to-late October. 1 and 2 instar larvae spit silk knots, cluster leaf pests, small food intake, weak drug resistance, after 4 years of age the food intake increased greatly, accounting for 88%-92% of the larvae's lifetime food, and dispersed as pests. When the onion tube is thoroughly gnawed, it burrows into the onion tube to hide and eat the leaf flesh, leaving only the outer skin, and after entering the binge eating period, the onion leaves are eaten, leaving only the underground part, resulting in ruined production and harvest.
Beet nocturnal moth adults lie out at night, lurking in the soil cracks, onions, leafy vegetables, grass and other hidden places during the day, nocturnal activity is exuberant, there are two peak periods of activity, that is, 7 to 10 o'clock in the evening and 5 to 7 o'clock in the morning for feeding, mating, egg laying, adult worms have a strong phototropism, when frightened for short-distance flight. The eggs are hemispherical, laid in clumps on green onion leaves, covered with a layer of gray phosphorus hairs, and the egg period averages 3 to 5 days. The hatching larvae have five ages, of which the 1st to 3rd instar is 4.5 to 7.5 days old. The larvae have suspended death, the larvae are frightened and roll into clumps, fall to the ground to fake death, and after a moment they begin to move again; there is migratory, when the onion leaves of a field are eaten, the swarm migrates to the surrounding plots or weeds to feed; there is fear of the sun, lurking in the onion tube or soil crack at noon on a sunny day, crawling out of the onion tube to eat in the evening and early morning, and going out to eat all day on cloudy days.
<h1>Scientific prevention and control</h1>
Because the waxy layer of the epidermis of the elderly larvae of the beet moth is thick and smooth, and the resistance to drugs is extremely strong, especially the 3.4.5-year-old larvae burrow into the onion tube, the liquid is difficult to spray on the larvae. Therefore, the best time for medication is the peak of egg hatching. At this time, the age is small, the drug resistance is low, and the fatality rate is high, and the opportunity should be seized to prevent and treat it in time. Pay attention to spraying in the evening on sunny days (looking for dead bugs in the field the next morning), and spraying throughout the day on cloudy days. Because the beet nightingale larvae have a suspended death, spraying should start from the lower part of the onion. Then penetrate from the bottom up on all sides, so that the frightened larvae will also fall into the medicine bush. This helps to exert the effects of the drug.
Medication: "Handan 140" 10 ml of water per bucket of water is sprayed evenly, sprayed in the afternoon of the first day, and looking for dead insects in the field the next day.
Related links: Insecticide "Handan 140": treatable resistant cabbage moth, beet nocturnal moth, two-point nocturnal moth!
Because the long-term continuous use of chlorantranium benzamide has led to changes in the gene sequence of the beet noctus fish nittin receptor, and the resistance multiple of 211-1005 times has been determined, the use of this type of agent to control beet noctule moth is very ineffective.
Control of shallot beet noctuidae moth