Recently, some farmers consulted “Isn't the corn seedlings in my farm field not a dead seedling, is it a long time to fill two seedlings or some small seedlings and weak seedlings?†The author found out through field observation that the plots of seedlings grow unevenly. The corn plants are seen from the ground, the tips of the leaves are dry, the lower leaf sheaths and leaves are dry, and some whole plants are wilting. After unplugging the corn seedlings, it was found that the root system had obvious nicks, and then opened the topsoil and found that there were pods near the roots of the corn. The average number of worms per plant was 2 to 3, resulting in lack of seedlings, wilting, dead seedlings.
Because the earthworms are damaging in the soil, they are not easy to be discovered by people, and the farmers' awareness of prevention and control is not strong. Now the seed coating agent is not ideal for the prevention and control of underground pests, causing damage to underground pests. In the middle and late July, the period of young larvae is the best period for chemical control, so to remind farmers to promptly check the treatment.
First, the morphological characteristics of corpus callosum hypertrophy, body shape was C-shaped, mostly white, a few yellow-white. The head is brown, the upper eyelid is prominent, and the abdomen is swollen. The body wall is soft and wrinkled, and the body surface is sparsely fine hair. The head is large and round, mostly yellow-brown. It has left and right symmetry bristles, and the three pairs of chest feet are generally longer.
Second, the symptoms of damage Earthworms inhabiting the soil, eating seed germination, biting off the roots and stems of seedlings, fractures neat and truncated, can cause wilting aboveground, lack of seedlings in the field ridge or destroy seed. Some species of adults take flowers and leaves, the wounds caused by it are conducive to the invasion of pathogens and induce diseases.
Third, the occurrence and damage rules are omnivorous pests, mainly damage wheat, corn, sorghum, beans, peanuts, sweet potatoes, etc., but also damage fruit trees and forest trees and their seedlings. After the field crops are damaged by larvae and adults, they cause ridges or ridges in the vacant crops or make the plants stunted, causing severe catastrophic disasters. The life history is longer. Except for part of the time, the adults live underground. In China, it takes 1 to 6 years to complete a generation. The larvae and adults become winter. There are suspended animation and phototaxis, and there is a tendency towards unfamed manure. Hide in the soil during the day and feed at 8 to 9 pm. The earthworms are always underground, closely related to the soil temperature and humidity, and the soil moisture activity is strengthened, especially continuous rainy weather. In spring and autumn, they are active on the topsoil, and in the summertime, they often reach the topsoil in the early morning and at night.
IV. Comprehensive prevention and control measures
1. Agricultural control. Water and dry crop rotations are used; irrigation is done at the right time during corn growth; intensive farming is done to repress soil in a timely manner to remove weeds in the fields; in severe areas, fall winter larvae can turn the overwintering larvae to surface air-dried, freeze-dried or predated by natural enemies; It is forbidden to use uncontaminated organic fertilizers in order to prevent adult insects from laying eggs.
2. Physical methods. Black light traps can be set to kill adults and reduce the number of ticks.
3. Biological control. The use of brown insect carp, black beetle black bee, Beauveria bassiana.
4. Chemical control. 1 Spray liquid: use 2.5% deltamethrin EC 2000 times, or 50% phoxim EC 1000 times, or 40% chlorpyrifos EC 1000 times to spray the ground during the appropriate period of control.
2 agent irrigate root. When the wilt seedlings were found in the corn field, they were treated with 50% phoxim 200 ml water and 400 kg water to root, or applied to plant stems for control.
3 poison bait trapping. When it is found to be harmful to underground pests, 50 ml of 50% phoxim EC should be mixed with 5 kg of cotton seed cake or freshly crushed grass. Poisonous baits or poisonous weeds are sprinkled near the roots of corn seedlings in the evening, spreading 15-20 kg per acre.
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