The harm of soybean aphids characteristics and comprehensive prevention and control measures

Soybean aphids mainly in soybean seedling stage, drought and little rain, continuous hot weather easily occur.It occurs, often be full of the soybean plant stem leaf, lead to poor its growth, podding reduction, big occurs yield decreased by 20% ~ 30%, serious more than 50%, seedling stage occurred serious when can make the whole plant death.Below small make up with all of you know about the characteristics of soybean aphids and comprehensive prevention and control measures, details are as follows:

1 aphids characteristics to the harm of soybean

1.1 direct damage

Soybean aphids in sucking mouthparts snorting of the plant leaf juice, leads to the formation of a blade, macular macular then gradually expanding, and brown.General years, soybean aphids more concentrated in the soybean plant leaves and tender stems;And serious, aphids is full of stem leaf, throughout the entire plant, cause plant small, stem leaves became brown and curled up, at the same time reduce the podding and branch number, the lower soybean production.Studies show that when by aphids damage after the soybean plant, the plant height, SPAD chlorophyll relative content per plant (), leaf area and aboveground dry weight were dropped.

1.2 indirect harm

Aphids not only directly harm the soybean after infection, but also a variety of plant viruses, such as alfalfa Mosaic virus (AMV), soybean Mosaic virus (SMV), tobacco ring spot virus (TRSV) and potato virus Y (PVY), etc.In addition, closely related to the ability to resist diseases and pests of soybean peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia enzyme (PAL) will change.POD and PPO activity between different strains to aphids after all have rise, and aphids inducing correlation;Aphids enroach on PAL activity were increased after the induction, aphid resistant strain performance is stable, PAL enzyme activity and soybean aphid resistance there is an obvious correlation.In addition, it says that the aphids soybean leaf tissues before and after the amino acids, flavonoids, alkaloids, phenols and other secondary metabolites is obvious changes have taken place.Aphids feeding on soybean isoflavone induced reaction has nothing to do with light, only related to whether plants were killed.

2 comprehensive prevention and control measures

2.1 breeding resistant varieties of diseases and pests

Cultivating aphid resistant varieties, is the most economic and effective way to solve the problem.Rely on the naturally occurring, ebb and flow, and the damage of the soybean aphid in soybean production field without human intervention, survey large DouYe aphids population, thus choosing aphid resistant materials as a parent to conventional breeding breeding aphid resistant varieties.Hilletal in soybean aphid choice experiment adopts the method of combining field experiment and greenhouse experiment, found "PI71506", "Jackson", "Dowling" and other varieties of soybean aphids occurred not significantly less than the resistance of soybean varieties (P = 0.05).Fan Yiheng affirmed the wild soybean resistance of soybean aphids, found that three performance is high, compared with the cultivation of soybean, the aphid resistance is higher, and is found in most aphid resistance materials.

2.2 control

One is the seed.Using soybean indicated coating, as well as the prevention and treatment of early aphids, and prevention and control of underground pests.Also can use efficient systemic pesticides, such as with 0.2% ~ 0.3% of the total seed 35% carbofuran seed dressing.The second is spraying.Prevention and treatment of soybean aphids, the key is early found early prevention and treatment.Soybean aphids discharge is honey ants very good food, so if you have ants in bean plants climb, will be found as early as possible.Slew at seedling stage with 35% v was 1.95 kg/hm2 spray, or acquaintances with 800 times liquid of phosphorus foliar spray, harmless to predators, and of soybean aphid control effect is remarkable.Soybean fields appeared some piece of harm, available synergistic pirimicarb agent 2000 times liquid, 40% omethoate ec 1000 times liquid spray, or choose 10% deltamethrin ec, live spirit was 5%, 5% decis was 225 ~ 300 ml/hm2, 600 ~ 600 l of water spray.Rotation should be paid attention to use a variety of pesticides, reduce aphid resistance, and protection of natural enemy.In view of the needs of the soybean aphid resistance and ecological environment protection, advocate high efficiency, low toxicity pesticides agent.To carry out rational drug use and protect the natural enemies for the principle.

2.3 agricultural measures

The weight of the soybean aphids occurred, closely associated with cultural forms, such as soybeans and corn in 8:2 interplanting of soybean aphid control effect is best, the peak amount of aphid than soybean farming and intercropping soybean and maize according to 8:8 fields, basic can effectively control the harm of soybean aphid [8].In addition, interplanting rape can effectively proliferation bean field number of natural enemies.

2.4 biological control

Soybean natural control for aphids is more, including the predatory ladybug, wasp, lacewing flies and food aphid fly, etc., in a number of natural enemies, can inhibit the increase of the number of the aphids.In soybean field release non-blue beetles, for example: after 10 d of soybean aphid control effect is as high as 90%.Bean field with bees for many consecutive years test showed that Japan bean aphid cocoon bees can make soybean aphid parasitic rate above 56%, and in the middle year rate of soybean leaf can be controlled under 1%.