The cultivars of Aquilegia praecox are localized pests in Xinji City. Because of their hidden dangers, the symptoms are like lack of fertilizer and lack of hormones, and they have not been taken seriously for a long time. Since the discovery of this insect in Zhaoxian and Mancheng in our province in the late 1980s, with the increase of the degree of mechanized cultivation, the degree of damage of this insect has become increasingly serious, and it has become an important pest that restricts the yield increase of corn.
I. Harmful symptoms The cultivars are mainly damaged by wheat, corn, millet, sorghum and other grasses and gramineous weeds. They attack female nymphs and nymphs in the leaf sheaths and roots near the ground to suck the sap of the host and intensively damage them. The light causes the stems and leaves of the affected plants to grow yellow and grow slowly. In severe cases, the plants are short and thin, and the lower leaves become dry or the roots and stems become thicker.
Second, the law of the occurrence of the worms occurred in 3 generations a year, 9 to 10 months each year, female adults lay eggs overwintering. In the middle and late April of the following year, the temperature begins to incubate at about 17°C, and the incubation period is more than half a month. The newly hatched nymphs first move within the oocysts for 1 to 2 days, and then spread around to find the host and fix them. The 1st instar nymph was lively and did not secrete a protective layer of wax powder, which was the best period for chemical control. After the 2nd instar, it began to secrete wax powder, and it was damaged in the ground or in the lower leaf sheath of the plant. The first generation took place from mid-April to mid-June, damaging wheat and sucking juice at the base of wheat stems. The second generation took place from mid-June to early August, damaging summer corn. The seedling corn had poor resistance and was the most affected. The third generation of corn or sorghum infestation from early August to mid-September has little effect on its yield.
Third, prevention and control measures
1. Fall down. The wheat and corn two-birth system provides favorable conditions for the spread of corn cultivars, such as sunflower mealybugs. Therefore, the heavy land masses should be dumped, and the summer sowing cotton or other dicotyledons should be planted to reduce the source of insects.
2. Chemical control. After the second instar nymphs attach wax powder on the body surface and are not easy to kill. Therefore, they should be used before the 2nd instar nymph, generally from late June to early July. Imidacloprid and pyrethroid pesticides can be used to remove sprinkler heads from the base of the corn stems by 1000 to 1500 times, so that the liquid flows down the soil to kill pests.
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