In recent years, the walnut planting area in Hengshui City of Hebei Province has been expanding, but it has also led to the occurrence of a large number of walnuts. How to prevent and cure walnuts? Let's take a quick look together. 1 morphological characteristics The common name of the walnut limb moth, also known as walnut black, belongs to the lepidoptera. The adult body is 4 to 9 mm long and has a wingspan of 10 to 15 mm. It has a dark brown body, a metallic luster, a red complex eye, a filamentous antennae, and a white fluff. 2 Law of occurrence In Hengshui City, Hebei Province, the walnut moth was first-generation in 1 year, and the old larvae were overwintered in the shallow soil layer under the canopy, bark cracks, soil joints, litter and so on. In the second year of June, the mature larvae began to sputum, and entered the phlegm period in mid-June. They began to emerge into adults in late June, and the adult feathers appeared in early July. Adults have frequent activities in the afternoon, resting on the back of the grass, branches and leaves. Mating and spawning are all between 16:00 and 19:00, and the sun is most frequent after the sunset. The egg is prolific at the intersection of the two fruits, the stalk and the petiole, and the fruit surface is rare. The eggs are scattered, and the end of June is the peak of spawning. In the end of July, the eggs are laid, and each female lays 40 to 50 eggs. Adults have strong phototaxis, and larvae begin to hatch in late June, and larvae hatch in mid-July. The mature larvae are detached from fruit in the middle and late August, and then they are frozen in the soil. 3 harmful symptoms After the hatching larva stays on the fruit for a while, it begins to crawl to find the fruit. The capsule time is 5-8 hours. After the larvae are dried, the colorless gelatinous secretion appears in the pores of the capsule, and then becomes a transparent white rubber beads, and the gradient is amber. After the larvae have dried fruit, they are stalked in the green skin. The initial damage period, the pores of the capsule are linear, deep into the nuts, making the peel dry and black, so it is also called "walnut black". The capsule hole tunnel is filled with insect feces, and the larvae of one fruit can reach several heads, and more than 30 heads are ruined. Early damage, walnut dysplasia, peeling and blackening of the skin, early shedding, but the larva does not turn the fruit. Some larvae eat fruit handles, causing early fruit drop. The mature larvae usually begin to take off the fruit in the middle and late August. At this time, the walnut skin becomes black and the pulp deteriorates and rots. When the old larvae take off the fruit, they first bite the peel and drop it to the ground. They crawl on the ground to find a suitable place to fill the soil for wintering. The fruit removal period is about 1 month. 4 Influencing factors The mountainous area is heavier than the plain, the shady slope is heavier than the sunny slope, the wasteland is heavier than the cultivated land, the damp low-lying ditch is heavier than the arid flat land, and the tree is seriously damaged during the fruit-bearing period, and the initial result tree suffers lightly. In the rainy seasons and years, when the weather is wet, the pests are serious, especially when there is a lot of rainfall from June to July, which is conducive to adult emergence and emergence. 5 Comprehensive control measures 5.1 Agricultural control (1) Cleaning the orchard hygiene and eliminating the overwintering insect source The walnut moths are overwintered by the mature larvae in the shallow soil and deciduous weeds under the canopy. Therefore, it is necessary to remove the litter and weeds in the garden in time to effectively reduce the occurrence of pests. (2) Deeply turning over the tree tray to destroy the wintering place of pests After harvesting the walnuts or deepening the tree trays before April of the next year, the depth of the tree is 15-20 cm, which can turn the wintering pests into the deep layers of the soil and cannot be feathered to achieve the purpose of prevention and control. In winter, the soil is turned over before freezing, and the wintering cockroaches can be turned to the ground, frozen or eaten by birds. (3) Picking up insects and fruits in the growing season, concentrated and destroyed In the growing season, before the larvae are detached, the damaged fruits under the tree on the walnut tree are picked up and destroyed in time. Picking up black fruit for more than 2 years, the control effect is more than 85%, this method is simple and economical and effective. 5.2 physical control The adult has a strong tendency to light-light. From June to August, black light is hoisted in the garden to trap the adult, and one insect killer is hung every hectare or 50 meters. 5.3 Chemical control (1) Ground application Before the adult feathers emerged, 50% phoxim emulsifiable concentrate 500 times was sprayed under the canopy to kill the adult. After the ground liquid is dried, the pesticide is well mixed with the soil to achieve long-term contact. (2) crown spray Starting from adult spawning, from 3 mid-June to mid-July, the canopy is sprayed three times, each spraying interval is 10 to 15 days, killing eggs and newly hatched larvae, and killing the larvae before the capsule. The medicament may be selected from the group consisting of 2.5% deltamethrin EC 1500 times solution and 25% Diflubenzuron No. 3 suspension agent 1500 times solution. Note that the spray should be before 10:00 or after 16:00. If the spray occurs within 6 hours, it should be refilled in time. (3) For the closed walnut forest, the adult can be smoked by a smoke machine during the adult period, and the drug is selected to be beta-cypermethrin: diesel = 1:4. 5.4 Biological control (1) Using natural enemies to control insects From June to July, the release of the natural enemies Trichogramma, releasing 300,000 heads per acre, can reduce the insect population density and effectively inhibit the damage of the walnuts. (2) Using microorganisms to control walnut limbs In the adult emergence period of 4 to 7 days, the larvae hatched the fruit of the scorpion, and the concentration was 200 million spores/ml. The control effect was remarkable. I saw the occurrence and prevention technology of the walnut limbs in Hengshui, Hebei. Do you think that the walnut growers feel that they have useful technical support for themselves? Be sure to prevent them in advance. Otherwise, the timing of prevention will definitely affect the quality and yield of walnuts. ! Deep Side Fertilization Machine Deep Side Fertilization Machine,Sounding Fertilizer Applicator,Rice Sounding Fertilizer Applicator,Paddy Field Fertilizer Applicator Taizhou Yingtian Agricultural Machinery Manufacturing Co., Ltd. , https://www.sakuradaagc.com
