Control of green bug bug in planting jujube

Green bug bug, also known as forage bug bug, can harm a variety of fruit trees, vegetables, cotton, alfalfa and other cash crops. In 2001, green bug bug occurred in a large area in Cangzhou jujube area, and seriously damaged the fruit, which is rare in history. According to the investigation of 26 jujube orchards in Yangsi and Liuzhuangzi, Huangdipu Township, Cang County, from June 16 to 18 (the peak period of the second generation green bug bug), there were an average of 2688 jujube trees per tree, and the highest one reached 4032. Cang County, Xian County and other jujube areas are common, with an area of nearly 667000 square hectares.

1 characteristics of occurrence and damage

The green bug sucks the buds and leaves of jujube trees with nymphs and adults. The juice of buds and young fruits. The damaged leaf buds first showed green spots, and with the extension of the leaves, the dots gradually turned into irregular holes, commonly known as "broken leaf disease" and "broken skylight". After the bud is received, it stops developing, dies and falls off, and in heavy cases, almost all the flowers fall off. After the young fruit is injured, some appear black necrotic spot, some appear bulging blister, its pulp tissue is necrotic, most of the injured fruit fall off, seriously affect the yield.

This insect occurs for 5 generations in one year in this area. Overwintering with eggs in weeds, diseased bodies and shallow soil. From March to April of the following year, when the average temperature is more than 10 ℃ and the relative humidity is about 70%, the overwintering eggs begin to hatch. The peak period of the first generation is in early May, which harms jujube buds. The second generation occurred in mid-June, harming jujube flowers and young fruits, which was the most serious damage to jujube trees. The third, fourth and fifth generations occurred in mid-July, mid-August and mid-September, respectively. The phenomenon of generation overlap is serious. It mainly harms legumes, corn and other crops under the tree.

2 causes of outbreaks and disasters

The main results are as follows: 1) the parasitic range is wide. Green bug bug used to be a pest on forage grass and cotton in this area, but with the adjustment of agricultural structure, it transferred to fruit trees, vegetables and other cash crops. Jujube trees, beans, eggplant and melons in this region suffered heavily in 2001, and some plots were even out of production.

2) suitable climatic conditions. The occurrence of green bug bugs is closely related to climatic conditions. The temperature of 20: 30 ℃ and relative humidity of 80% to 90% are the most suitable for its occurrence. The average temperature in April 2001 was 21 ℃, and the rainfall on April 29th was 25.6mm. The temperature and humidity were very favorable for the hatching of overwintering eggs, which led to the peak of the damage of the first generation green bug bug in the first and middle of May. On the one hand, it directly affected the flower bud differentiation and bud development of jujube, on the other hand, it directly damaged the young buds, caused the bud to fall off, and affected the formation of flower buds in the future. This is one of the reasons for the lack of jujube buds in 2001. On June 13, 14 and 16, there was continuous rainfall of 35 mm in this area, coupled with the unsatisfactory control effect of the first generation green bug bugs and a large population base, which led to the outbreak of the second generation green bug bugs. According to statistics, the fruit drop rate is up to 40%, and the weight is as high as 70%, reducing the output of jujube by 30% and 60%.

3) the prevention and treatment is not timely. Green bug bug has been found in this area since 1986, but it has not been effectively controlled. On the one hand, because the adults often climb to the leaves and buds at night or early in the morning, they crawl quickly after being frightened, and because of their small size and similar body color to the leaves, it is not easy to be found. On the other hand, because over the years, the occurrence of irregular, small scale, does not constitute a disaster, thus causing attention in production. It was also not listed as the key control object in 2001. by the time it was found that it was seriously harmful to jujube fruit, the green bug bug had grown into an adult, had strong flying ability, missed the opportunity of spraying, and was difficult to control.

3 methods of prevention and control

1) Agricultural prevention and control. Green bug bugs overwinter with eggs in withered branches, weeds and rough skin cracks. Combined with clearing the garden in winter and scraping the bark in spring, the overwintering eggs can be reduced. Or in the middle or late March, combined with scraping bark and spraying Baume 3-5 °stone sulfur mixture, part of the overwintering eggs can be killed.

2) Chemical control. The hatching of green blind bug eggs needs more than 65% relative humidity, so it is necessary to spray in time in the nymph stage of each generation in early May, mid-June, mid-July and late July according to the weather conditions. The effect of mixed spraying with good contact ability and strong internal absorption is the best. For example, 4.5% cypermethrin EC 2500 × 3000 times solution and 5% acetamiprid (green garden 2 EC) 3000cm 3500 times solution are sprayed. Because green bug bugs generally lurk on weeds and inter-row crops under trees during the day and do harm to trees at night, spraying should focus on tree trunks, aboveground weeds and inter-row crops. So that the tree under the tree spray strict, spray all. Once adults occur, it is necessary to spray the whole village or even the whole township jujube farmers in the evening or morning to prevent the adults from flying and achieve the goal of eradication.