Jujube step qu, also known as jujube inchworm and jujube ruler moth, occurs widely in jujube tree planting and production areas, with the northern jujube area suffering the most. Therefore, farmers must take measures to prevent and control it. The following is a detailed summary of the harmful symptoms, occurrence rules and prevention measures of jujube tree jujube steps, hoping to help farmers.
Hazard Symptoms:
Larvae harm date buds, flower buds and leaves. When the jujube buds germinate to reveal green, the hatching larvae begin to harm the young shoots, so the masses call it "top door eating", and in severe years, the jujube buds can be eaten up, forming a "dried plum", resulting in a large reduction in production. When the jujube tree spreads its leaves and flowers, the larvae grow up, the amount of food is significantly increased, and all the leaves and buds can be eaten, which not only causes a no-show that year, but also affects the next year's fruit.
Occurrence rules:
Jujube step qu occurs once a year, and a very small number of two generations occur every year, pupating in the soil layer 0.7-1 cm deep under the canopy. From late March to early April of the following year, when the willows sprout and the elms bloom, the adults are feathered and emerge, and at this time they enter their prime. The feathering period lasts for more than 50 days, after the adults are feathered, the male climbs to the shady side of the trunk or the ground weeds to lie still, and the female moth first lurks on the surface of the soil and then climbs to the surface. It is common to crawl at night on trees to lay eggs. The initial stage of field egg laying is in early April. The eggs are laid in chunks in the crevices of the main trunk and coarse skin of the main branches, or under the stones and soil crevices at the base of the trunk. When the jujube buds sprout and dew green, the eggs begin to hatch, when the jujube trees spread their leaves and the apples fall flowers, the field eggs hatch into the peak period, and the larvae mature into the soil to pupate overwintering. In the year when March to May is particularly dry, adult feathering can be inhibited, and the damage is light in that year. At such a time, there is a lot of rainfall, which is conducive to the excavation of feathering, if the rain is delayed, the peak period of the feathering excavation time is delayed. The soil moisture is large, the texture is loose, which is conducive to the feathering of adult insects, and the feathering is neat, the number is large, and the harm is particularly serious.
Prevention and control measures:
1. Prevent female moths and hatching larvae from going up the tree: Before the adult jujube step is feathered and unearthed, tie a 10 cm wide plastic film 1 circle at the base of the trunk 10 cm from the ground, and require it to be close to the trunk, and the joint is glued or nailed with staples or plastic tape. The lower edge of the plastic belt is compacted with soil, and a small cone-shaped mound is made of fine soil, and a small ditch is opened at the base of the mound, and the ditch is sprinkled with 1:10 of the enemy insect poison soil, or octyl thiophos powder, which can eliminate most of the female moths on the tree.
2. Egg binding method: tie a circle of grass rope under the plastic film belt, which can induce female moths to lay eggs in the gaps of grass flies, and when the eggs are close to the incubation period, the grass rope will be untied and burned or buried deeply.
3. Spray control method on trees: about 25 days after the peak of egg hatching or the peak of adult feathering, to ensure that the larvae are eliminated before 3 instars. Jujube orchards with large insect population density and heavy occurrence, combined with investigation, should be used for the second time about half a month after the first dose. The agents used are 50% octylthion emulsion 1500 times liquid, 90% dimethoate emulsion 1000 times liquid or 50% dichlorvos emulsion 1000 times liquid (these two agents are banned before the physiological fruit of the apple tree, there is a medicinal harm), or 2.5% cypermethrin emulsion, 20% permethrin emulsion, 20% rifling emulsion, 2.5% kung fu emulsion 2000 times liquid. In addition, the larval stage can also use Thuringiensis, acaricidal bacillus, Cypercus cyanobacteria, 7216 (10 billion spores / g) to contain about 0.5 billion spores per gram of dilution. The effect is also very good.
4. Other control methods: such as digging pupae in autumn or early spring, catching adult insects during the feathering period, scraping tree bark to kill eggs, using jujube step larvae with pseudo-dead vibrating insects to kill, and areas with lack of water in mountain areas can use 741 dichlorvos intubation aerosol to smoke for about 40 minutes, and the larval mortality rate can reach 87.3%.
5. Protect and utilize predators.