Since 2005, a pest has been found to harm summer corn, and in 2011, the Huang-Huai-Hai summer corn area suddenly broke out, resulting in a large area of summer corn being destroyed and replanted (reported to harm an area of 40 million mu), it is the two-point night moth!
What is the two-point nocturnal moth?
The two-point nocturnal moth belongs to lepidoptera, molts 5 times in the larval stage for a total of 6 years, afraid of light and high temperature, diurnal and nocturnal, and has the harmful characteristics of the plant! The larvae are heterogeneous and can feed on more than 30 species of plants in more than 13 families, mainly endangering summer corn in our land. And because the site and appearance of the victim are very similar to the tigers in the small land, sometimes farmers often misidentify it.
The figure shows the key points of identification of the larvae of the two-point nocturnal moth
The picture shows the key points of identification of ground tiger larvae
The picture shows the difference between the two-point nocturnal moth and the common ground tiger
The harm of the two-o'clock nocturnal moth to corn
The two-point nocturnal moth mainly harms corn seedlings with larvae hiding under the broken wheat straw around the corn seedlings or in the topsoil layer of 2-5 cm, mainly nibbling on the base of the corn stem, and the following symptoms can be formed according to the growth period of corn:
2-3 leaf stage hazards cause maize seedlings to die from root bites.
3-4 mm voids form at the base of the stem of moth-fed corn at the 3-6 leaf stage, resulting in wilting and death of corn heart leaves.
At the 7-10 leaf stage, bite the secondary root or main root of corn, causing lodging, severe death, if not controlled, it will lead to a large shortage of corn seedlings, seriously reducing yield!
Occurrence time of the nocturnal moth at two o'clock
The two-point nocturnal moth generally occurs more in the summer corn field of wheat stubble, and the distribution of pests in the field is uneven, but the edge ridge near the ridge is serious, and the general flaky hazard area is about 4 square meters! The investigation found that the wheat straw bran cover was serious, the cotton and wheat flower arrangement field was serious, the sowing was serious, and the sowing ditch was shallow.
Generally, mid-June is the peak of the occurrence of overwintering adults, and in late June and July, the overwintering adults lay eggs and hatch the larvae that eat the stem base of corn seedlings, and this year it is predicted that the larvae of the two-o'clock nocturnal moth will occur in a large area from June 22 to early July.
The picture shows the adult of the two-point nocturnal moth (one black and one white dot on the forewing)
Prevention and control methods
The control of the nocturnal moth is divided into agricultural measures and chemical control, and the key methods that should be mastered in the prevention and control work should be mastered early prevention and control, and when it is found that there are individual plants in the field that are tilted or cored, the prevention and control should be started immediately.
Agricultural measures: timely removal of wheat straw, weeds and other mulch at the base of corn seedlings, promote stubble sowing, and eliminate favorable environmental conditions for their occurrence. Be sure to remove all the wheat bran straw covered in the corn ridge to the corn rows away from the plant and expose it to the ground so that the agent can directly contact the two-point night moth.
It is just that the prevention and control of the whole field medicated spray instead of the shunlang irrigation root has almost no effect, and the corn field prevention and control effect of the corn field that does not clean the wheat straw and wheat bran only the shunlang medicinal root irrigation is slightly worse.
The best control method for agricultural measures: after cleaning the wheat straw and wheat bran, use a motorized sprayer, adjust the spray gun into a water column to spray the corn root directly, and at the same time cultivate soil seedlings.
Chemical control: The main methods are seed mixing, spraying, poisonous bait, poisonous soil, watering and so on. When spraying herbicides before spraying, a mixture of permethrin or methyl vitamin salts can be added, and the number of insect mouth bases in the later stage can be greatly reduced after application! After years of measurement and testing, it was found that after the emergence of seedlings, it was found that the poison bait method was the best effect when controlling insect conditions, and the operation was simple, time-saving and efficient!
Poison bait: Mu with 4-5kg of stir-fried wheat bran or crushed and sautéed cottonseed cake, mixed with a small amount of water, mixed into poisonous bait, in the evening along the ridge sprinkled on the edge of corn seedlings.
Sprinkle granules or poisonous soil: 50% octyl thiophos 150-200ml mixed with fine sand or fine sand soil 50kg per mu, or 80% dichlorvos emulsion 300-500ml mixed with 25kg fine soil per mu, sprinkle on the edge of corn seedlings in the morning and row hoe.
Irrigation with watering: Corn fields that need to be watered can be irrigated with water and poured into the field when watering.
Implementation of early medication: spraying corn rhizomes with agents.
Adult insects that inhabit the wheat stubble must be killed, especially in the lodging wheat field, emphasizing 2 times of medication. In general, before sowing the seedlings, first go to the field again, such as startling moths and large numbers, please spray the medicine immediately to kill. According to actual measurements, spraying adult insects has a 90% control effect.
Reference: Longchi Agricultural Technical Service Center
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