Cotton blind bug is a pest that seriously endangers the growth of cotton in our region, and its harm shows a trend of increasing year by year, which seriously affects the benefits of cotton planting and the development of cotton planting industry. This paper summarizes in detail the occurrence law and prevention and control countermeasures of cotton blind bugs for your reference.
First, the characteristics of harm
Cotton blind bugs are formed and nymphs suck the sap on the top buds, young leaves, flower buds and young bells of the cotton plant. The young shoots are victimized to form "male" cotton with only two thick cotyledons left; Leaf damage forms a large number of broken holes, wrinkled "leaf breaking madness"; Axillary buds and growth points are damaged, causing axillary buds to grow, and broken leaves are like broom seedlings; The young buds become yellow-brown and dry. Cotton bell victims black dots are covered with cloth, rigid and fall off; It causes the cotton bud bell to fall off, which seriously affects the cotton yield.
Second, the law of occurrence
Cotton blind bugs mainly include pasture blind bugs, alfalfa blind bugs, green blind bugs, medium black blind bugs and three-point blind bugs, and the hazards of green blind bugs in our area are mainly grass green blind bugs. Cotton blind bugs occur in 3 generations per year, and the eggs overwinter in the shell of the dead branches of cotton or in the stems, stubbles, fruit bark or broken branches, and soil of the cotton dead branches. In the first and middle of April of the following spring, the average temperature is higher than l0 °C or the average temperature reaches 11 °C for 5 consecutive days, the relative humidity is higher than 70%, and the eggs begin to hatch. Adults are highly flying, like to eat nectar, and begin to lay eggs 6 to 7 days after feathering.
Non-overwintering eggs are mostly scattered in the young leaves, stems, petioles, veins, young buds and other tissues of cotton and other plants, exposing the yellow egg cap, and the egg period is 7 to 9 days. In recent years, the cotton blind bugs have moved into the cotton fields earlier, they can move into the cotton fields in May, and from late May to mid-June, they enter the peak period of cotton field harm, that is, before and after the cotton buds. In mid-to-late August, the buds of the cotton field gradually moved out of the cotton field. Fruit trees suffer heavily in spring and autumn. The main predators are parasitic wasps, grasshoppers, predatory spiders, etc.
Cotton blind bugs like warm and wet, tender, flowering, adult insects to avoid strong light, before 9 a.m. or after 8 p.m., at the top of the cotton plant activities, nocturnal activities to feed, but rainy days can be active all day. The suitable temperature is 25 ~ 30 °C, and the relative humidity is more than 80%. In May, when the rainfall is heavy and heavy, the occurrence of blind bugs will be aggravated. Generally sown early, seedlings grow early, grow vigorously, and bud early in cotton fields, blind bugs enter early and are seriously harmful. Densely planted, tall and dense plants, growing young green cotton plants with high nitrogen content suffered heavily.
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