【Author:Lao Dao Network Yuan Juan】
Twill nocturnal moths are also known as lotus moths, night thieves, aconitum, lotus leaf worms, five-flowered worms, blackhead worms and so on. It is a worldwide distribution of pests and has a migratory habit. In China, the nocturnal twill moth was first reported in 1988 for harming bananas.
First, the occurrence of regional distribution. In the Yellow River Basin, August to September is a period of serious harm, sweet potatoes, vegetables and other crops are more seriously damaged, and cotton is less damaged. In central China, 2 to 4 generations of cotton are harmful, and the amount of cotton is large from July to August, and the damage is the most serious. The first generation of moths in mid-to-late June, mostly in vegetables, green manure for harm, the second generation in late May to early June, partly transferred to the cotton field to lay eggs, the third, fourth, 5 generations occurred in early to mid-July, early august and early september, October to November can also occur the sixth generation.
Second, generations: in North China, 4 to 5 generations occur every year, 5 to 6 generations in the Yangtze River Basin, and 6 to 9 generations in Fujian. The larvae have uneven development due to different feedings, resulting in serious generational overlap.
Third, wintering: most of North China overwinters with pupae, a small number of old mature larvae into the soil as a room for wintering; in South China, there is no diapause phenomenon, year-round breeding; in the area north of the Yangtze River Basin, the problem of wintering has not yet been concluded. Fourth, climate: Twill moth is a thermophilic pest, its growth and development of the most suitable temperature and humidity conditions of 28 ~ 30 °C, relative humidity of 75% ~ 85%. High temperatures above 38 °C and low winter temperatures are not conducive to the development of eggs, larvae and pupae. When the soil moisture is too low and the water content is below 20%, it is not conducive to pupal pupae and adult feathering. 1st to 2nd instar larvae die in large numbers in storms. Heavy rain during the pupae period, the accumulation of water in the field is not conducive to feathering. Fifth, cultivation: the field water is good, the crop growth is luxuriant, and the density of insect population is often large. The soil moisture content is less than 20%, which is not conducive to pupae and feathering.
Habitual characteristics
First, life habits.
(1) Adult insects: After feathering, adult insects lurk under the leaves, soil gaps or other hidden places during the day, and begin to eat nectar as supplementary nutrition after dusk, and then they can lay eggs. Each female can lay 8 to 17 eggs, about 1 000 to 2 000 eggs, up to a maximum of 3 000 grains. It is more prolific on the back of the upper part of the tall, densely leafy cotton plant, and rarely on the front of the leaf, petiole and stem. The presence or absence of nutritional supplementation has a great impact on spawning, and those who do not take nectar lay very little eggs. Adult worms have a strong tendency to sugar, vinegar, liquor and fermented carrots and bean cakes, and also have a strong tendency to black light.
(2) Larvae: the hatching larvae cluster leaf back to feed on the epidermis and leaf flesh, and have the habit of spitting silk with the wind; disperse the pest after 2 and 3 years; the larvae before the 3rd instar eat the leaf flesh, leaving the epidermis and leaf veins, which are window-screen-shaped; the food intake at the end of the 4th instar is greatly increased, the bite of the leaf is missing, leaving only the main vein, and eating the young stems, buds and flowers; the 5th to 6th instar larvae enter the gluttony stage, and the amount of food accounts for more than 90% of the total food intake of the larvae. It is in full bloom from July to October every year, of which the Yangtze River Basin occurs mostly in July and August, which seriously harms cotton, sweet potatoes and vegetables.
Second, the characteristics of harm. The larvae feed on leaves into missing or holes.
Third, it is harmful to crops. More than 290 species of plants in 99 families, such as nightshade, legumes, cruciferous family, green leafy vegetable artemisia, amaranth, lettuce, lettuce, green vegetables, etc.
Prevention and control methods
First, agricultural prevention and control: timely ploughing of idle fields, eradication of weeds on the edge of the field. At the peak of larval pupae, the pupae are cultivated in combination with agricultural operations to reduce the population base of insects in the field. During the pupal stage of the twill moth, combined with drought resistance irrigation, most of the pupae can be drowned and the cardinality can be reduced. From the peak spawning period to the initial incubation period of the twill moth, the eggs are manually removed and the hatching larvae are used as harmful leaves, and they are taken out of the field for centralized destruction. Rationally arrange the planting stubble to avoid continuous crop cropping of the twill moth host crop. Where conditions permit, it can be rotated with rice.
Second, physical control: adult insects in full bloom, the use of black lights, sweet and sour liquor to trap adult insects.
Chemical Control - Pharmaceutical Reference
1 billion pib/ml Twill nocturnal moth nuclear polyhedral virus suspension agent (low toxicity) use 50-75 ml/mu spray
10% ether permethrin suspension (minimally toxic) use 80-100 g/mu spray
10 billion spores/ml Short stable bacillus suspension (low toxicity) using 800-1000 times liquid spray
13% polyclaptotical acarbonitrile suspension (low toxicity) use 24-29 ml/mu spray
14% insect mite indigovirus suspension (moderate toxicity) use 10-20 g/mu spray
30% avivine suspension (low toxicity) use 0-50 ml/acre spray
0.5% matrine water agent (low toxicity) use 60-90 ml/mu spray
2.5% High Potency Cypermethrin Water Emulsion (Moderate Toxicity) Use 40-50 ml/acre spray
5% methylvin perchlorofluoride emulsion (moderately toxic) use 8-12 g/mu spray
3% mevinpyridine microemulsion (low toxicity) use 40-50 g/mu spray
4% methylwid folamide microemulsion (low toxicity) use 9-17 ml/mu spray
3.2% Methyl vitamin salt cyanide microemulsion (moderately toxic) use 40-60 ml/mu spray
6% avyl chlorobenzoyl suspension (low toxicity) use 40-50 ml/acre spray
50% insect mite butyl ether urea suspension agent (low toxicity) use 15-35 g/mu spray
43.5% butyl etherurea suspension (low toxicity) use 57-80 ml/mu spray
25 g/L polycyctomycin suspension (low toxicity) use 33-66 ml/mu spray
12% mevinia nitrile suspension (low toxicity) use 40-45 ml/acre spray
25% methylpyridine suspension (low toxicity) use 10-15 ml/mu spray
240 g/L Methoxyhydrazide suspension agent (low toxicity) Use 10-20 ml/mu spray
22% Cyanofloxoniax suspension (low toxicity) use 60-80 ml/acre spray
40% Bellicidal Suspension (Low Toxicity) Use 14.4-18 ml/acre spray
3 billion pib/ml beet nocturnal moth karyotype polyhedral virus suspension agent (low toxicity) use 20-30 ml/mu spray
8000iu/μl Bacillus thuringis suspension (low toxicity) use 100-150 ml/mu spray
150 g/L indoctrine suspension agent (low toxicity) use 10-18 ml/mu spray
60 g/L ethyl polybactericide suspension (low toxicity) use 20-40 ml/mu spray
30% Chlorpyrifos microcapsules suspension (low toxicity) use 65-95 ml/acre spray
5% chlorpyrifos benzamide suspension (minimally toxic) use 45-54 ml/acre spray
10% Mevin indate suspension (low toxicity) use 8-12 ml/mu spray
2% methylaminoavermectin benzoate microemulsion (low toxicity) use 5-7 ml/mu spray
40 billion spores /g Coccidioides Albicans wettable powder (low toxicity) Use 25-30 g/mu spray