From the production practice, the species and occurrence law of the late-eyed mushroom mosquito in high-density areas were found, and it was proposed that the harvest season of leek planting, especially before wheat harvest, was the key period for the prevention and control of late-eyed mushroom mosquitoes, and the application of biogas slurry should be vigorously promoted in production to prevent and control late-eyed mushroom mosquitoes, and an efficient and economical comprehensive management plan should be formulated to meet the requirements of producing pollution-free leeks.
< h1 class= "pgc-h-arrow-right" > 1 morphological characteristics</h1>
Chick-eyed mushrooms are in the order Diptera, Asteraceae, Andychophyllaceae, and the larvae are commonly known as leek maggots. There are two species of chives late-eyed mushrooms, namely Leek Late-eyed Mushroom Mosquito and Lu's Late-Eyed Mushroom Mosquito, according to field surveys, the population of late-eyed mushroom mosquitoes in high-density leeks accounts for 98.37% of leek root maggots, which is the dominant species of leek maggots. The adult is dark brown, mosquito-like, and the male has a broad ventral end and a curved apex at the end of the gripper. Females are similar in traits to males , with a thick mid-abdomen , a gradually thinning and pointed tip at the end , and a pair of 2-segment tail whiskers at the ventral end.
The larvae are 4 years old , nearly spindle-shaped , translucent , with a milky white , pitch-black head , hard , no feet , visible through the abdominal wall of the digestive tract. Pupae are naked pupae with colostrum white , the posterior cephalothorax becomes yellowish brown , and the pre-feathered grey-black color. The egg is oval, milky white, and is about to hatch when small black dots appear at one end of the egg shell.
<h1 class= "pgc-h-arrow-right" >2 occurrence</h1>
Under natural conditions, it takes 25-30 days for The leek to complete a generation, and the overwintering generation is nearly half a year. The larvae are mainly horizontally active in spring and autumn, and after hatching, they spread horizontally first, which harms the leaf sheath, young stems and buds of leek plants, causing the young stems to rot and the leaves to wither and yellow, and then bite off the stems and enter the stems. In summer, the larvae move downwards and burrow into the bulbs, causing the bulbs to rot and causing the leek mound to die. In winter, dive 3 cm under the soil to overwinter. The leek late-eyed mushroom mosquito has a wide range of temperature adaptation and can safely overwinter in most parts of the country, while there is no overwintering phenomenon in the shed, and it can continue to breed as a pest.
The larvae dormant overwinter mainly in the soil around the leek root or in the stem, and when the leek germinates in the spring of the following year, it begins to move and feed. The time for wintering larvae in the greenhouse to feather into adults is in mid-to-late March, and the first generation of larvae hatches through cross-tail laying eggs, the time for the first generation of larvae to pupate into adults is in mid-to-late April, and the second generation of adults appears in late May.
In high density, it generally enters the peak of larval harm at the end of April and mid-May. The bulbs and young stems that are gathered in the underground part of leeks are harmful to moths, and the harm is more serious in spring and autumn. The light causes the dwarfing of some plants on the ground of leeks, the leaves are green, the yellow wilts, the plants become soft and lodging, resulting in poor quality, the yield is reduced, and the heavy ones cause the lack of seedlings and ridges, the broken stems and the rot of the stem base, causing the death of the whole pier leeks, and the yield loss is 30% to 80%.
The arrival of the summer rainy season is not conducive to the survival of leek maggots, and the amount of insects has a tendency to decrease. Adult insects like to be active in the shade and humidity of weak light, flying at 9:00 to 11:00, the most active tail, 16:00 to night often lurking in the ground or crevices, there are multiple tail habits, 1 to 2 days after the tail, choose to lay eggs on the leek stem and the soil gap, leaf sheath gap and soil mass, most of the eggs are pile-shaped, the average female lays about 100 eggs. The larvae feed on the internal tissues of leeks, mainly by drilling through the epidermis of the roots, and then enter the marrow with the decay of the host, and most of the old mature larvae will pupate in the shallow soil layer outside the host.
The larvae have a habit of being wet and afraid of drying, and when the water content of the 5cm soil layer is less than 20%, the impact on its occurrence is relatively large, such as the high temperature and drought weather in summer have a significant impact on the occurrence of leek maggots in autumn. In general, leeks are harmful on sandy loam soil and newly colonized leeks. In spring and autumn, the duration of the adult stage, egg stage, larval stage and pupa stage of Leek Late-eye Mushroom mosquitoes is generally 3.0-6.5, 4.5-8.5, 15.0-18.0, and 3.0-7.0d, respectively.
<h1 class = "pgc-h-arrow-right" > 3 leeks for the control of late-eye mushroom mosquitoes</h1>
3.1 Agricultural control
(1) Seedling transplanting: Newly planted leek gardens can adopt the seedling transplanting method, and seedling transplanting can not only improve the efficiency, but also reduce the harm of leek maggots. The seedbed selects fertile winter idle land, and determines the seedbed according to 1:9, that is, 9 acres of seedbed can be transplanted per mu, the seedbed is made into a furrow width of 1.5m, the furrow length is determined according to the needs, and the seedlings are bred before and after the sting. Seedlings can be soaked with biogas slurry, and the seeds soaked in biogas slurry have strong buds, high seedling formation rate, developed root system, many elk, vigorous growth, drought resistance, strong disease resistance, and leeks have obvious yield increase effects after biogas slurry soaking.
(2) Crop rotation: timely stubble change can reduce the harm of leek maggots, generally once every 5 years. Leek late-eye mushroom mosquitoes occur in serious plots, and rotation is implemented for more than 3 years. (3) Reasonable fertilization: apply fully decomposed organic fertilizer, and avoid using fecal thinness and nitric acid saddle as topdressing when leeks are infested with late-eyed mushroom mosquitoes. (4) Irrigation method to control root maggots: in the spring or autumn when the larvae occur, continuous watering for 2 to 3 days, submerge the ridge every day, kill leek late-eyed mushroom mosquitoes. The ground cover with fine sand and grass and wood ash can dry the ground, reduce the water content, which is not conducive to adult egg laying and larval hatching, and is prone to water loss and death.
3.2 Biogas slurry control
Biogas slurry is a kind of decomposing quick-acting fertilizer rich in a variety of water-soluble nutrients, which can be quickly absorbed and utilized by crops, promote crop growth and development, enhance the ability to resist diseases and insect pests, and significantly increase yield and improve quality. After anaerobic fermentation, the biogas slurry contains a large amount of mycelium, high concentrations of ammonia and ammonia nitrogen, so it has a strong ability to control diseases and insect pests. According to the occurrence law of the leek late-eyed mushroom mosquito, leek is a shallow root crop, and the roots are irrigated with biogas slurry when the eggs of the late-eyed mushroom mosquito have not yet been harmed at the beginning of egg hatching. Along the leek ridge irrigation and ditch irrigation, such as the amount of biogas slurry is limited, you can peel open the topsoil, irrigate and then cover the soil. The downfiltration depth of the biogas slurry after root irrigation is 10-15 cm, and then irrigated once a week, satisfactory results can be obtained.
3.3 Film application technology
Practice has proved that the use of small arch shed buckle film cultivation can not only eliminate the harm of 1st and 2nd generations, control the base number of insect mouths of 3rd and 4th generations, but also increase the harvest stubble and advance the harvest time of the head stubble. The leek furrow should be 1.5 m wide and 1.8m long, 1.5 m between the arch and the arch, and the thickness of the agricultural film is 3 silk. In early February, the film is buckled, only one side is peeled off during harvesting, then covered tightly after cutting, and the film is removed when harvested in late May.
3.4 Ecological control
Immediately after harvesting the leeks 1 time, water the leeks with fresh urine, the soil is not watery when wet, 50% of the water when the soil is dry, and then sprinkled with hay ash. This leaves the soil surface dry for a long time and prevents the eggs from hatching. During the harvest season, raw manure is prohibited from being watered and no ecological conditions are created for leeks.
3.5 Physical control
Use unripe manure or rotten and moldy garlic cloves, mash and add a small amount of insecticide to trap adult insects, or you can use sweet and sour solution to trap. The method is: sugar, vinegar, wine and 90% of the insects according to the ratio of 3: 1: 10: 0.1, first dissolve the sugar with water, and then add vinegar, wine, water and pesticides, generally every 30m² put a booby trap basin, every 7d to change the booby trap solution, every 1d to add vinegar.
3.6 Chemical control
At present, the control of leek maggots in high-density production is mainly based on chemical control, in order to further improve the prevention and control effect, it is necessary to determine the appropriate period for prevention and control before prevention and control. It can be considered from the following two aspects: first, before the wheat harvest, that is, in early and mid-May, it is the outbreak period of the larvae of the leek late-eye mushroom mosquito, and after the harvest of leeks, regardless of whether there are harmful symptoms, it must be filled with medicine in time; second, according to the symptoms of leeks, the leaf tips begin to yellow and become soft, and gradually fall to the ground, that is, the early stage of leek late-eyed mushroom mosquitoes is harmful, and irrigation control should be taken; third, according to the law of occurrence of harm, the favorable period of prevention and control is the peak period of adult feathering and the peak period of larval harm. The control of adult insects is in the peak of the female insects, and the spraying time is better from 9:00 to 11:00 a.m.
The control of larvae should seize the peak period of the first generation of larval harm, that is, the control of the first generation of larvae is appropriate, the extermination of the third generation of larvae should be in mid-to-late July, and the autumn leek late-eye mushroom mosquito occurs in mid-to-late October. Successful spring prevention and control can reduce the annual hazard, and autumn prevention and control can reduce the overwintering base. The specific methods are: spraying to control adult insects: adult feathering peak (about late March to early April), with 40% octylthion emulsion, 80% dichlorvos emulsion 1000-1500 times or 2.5% desert permethrin emulsion 3000 times, sprayed at 9:00 to 11:00 a.m., sprayed once in 10 days, sprayed 2 to 4 times.
Irrigation with water: 1200ml of 22% vitilbene octylthion emulsion per mu, or 1.8% avidin emulsion 3000ml, 1% methyl vitamin salt emulsion 4000ml, the control effect is better. Severely injured plots are re-administered at intervals of 10 days after the first application. To kill adult insects: each shed (about 667 m²) is mixed with 50% dichlorvos 0.4 kg into 30 kg of fine sand, mixed well and sprinkled on the ridge before 11:00 a.m. When applying the drug, it is necessary to close the shed and ventilate after 2h, which is not only highly effective, but also has little pollution and saves labor.