There are more than 10 kinds of diseases and insect pests that can occur on soybeans, of which the bean root snake diving fly is a common pest in the soybean planting process, and the bean stalk black diving fly is "equally famous", which specifically endangers the roots of soybeans, causing plant stem necrosis, root cracking and underdevelopment, and finally dying, which is a more specific and harmful pest.
Especially in the summer of each year, this period is the peak of the harm of the bean root snake fly, if the early prevention work is not done in place, then the field will erupt, soybeans will suffer serious harm, so that farmers have a headache.
<h1 class="pgc-h-decimal" data-index="01" > Why is it that the "bean root snake diving fly" outbreak will cause farmers a headache? </h1>
First, the adult and larvae of the bean root snake diving fly can cause damage to soybeans, after its outbreak in the field, the adult worm will use the mouthpart to puncture and lick the young leaves of the seedling plant, causing the symptoms of dead spots on the leaves, affecting the normal photosynthesis of the leaves; the adult mates mating and laying eggs hatched larvae will drill into the roots of the seedlings for feeding, endangering the cortex and wood of the main root, causing strip scars, and eventually causing the root system of the plant to become thicker, brown, the skin layer cracked or deformed, the root system as a whole is weak, and the root rot is serious.
Second, due to the damage to the root of soybean root, the root system is weak and underdeveloped, which affects the growth of the aboveground part, so that the plant shows weak seedlings, small stems, stunted plants, yellowing and other deficiency phenomena, and finally the whole plant gradually withers.
Third, after the bean root snake fly endangers the roots of soybean seedlings, in addition to causing the root system to be underdeveloped, the wound cracks in the root system are conducive to the invasion of other soil-borne disease pathogens, resulting in difficult and complicated diseases that occur at the same time as insect diseases, so that farmers cannot feel the headache, can not be prevented and controlled by timely and accurate medication, and eventually cause serious losses.
<h1 class="pgc-h-decimal" data-index="02" > why do farmers find "bean root snake fly" difficult to fight? </h1>
Bean root snake fly is actually not difficult to fight, in terms of drug resistance, many drugs are very good control effects on it, but many farmers do not know the habits of bean root snake fly, or sometimes do not notice these control techniques.
1. The habits of the bean root snake diving fly itself
Bean root snake diving fly is a more specific pest, only eat damage to soybean plants, they in the form of pupae in the form of overwintering near the roots of the plant, pupal period is very long, after soybean sowing began to feather adults, after 2-3 days, adult insects choose to mate, breed, spawn during the day morning or evening, eggs can hatch after 3-5 days to hatch larvae, larval period is more than 20 days old, until late July to begin pupating;
The peak period of adult egg laying and the peak period of larval hatching are the best periods for the control of bean root snake diving flies, and farmers can only better control measures if they have mastered the life habits and occurrence rules of bean root snake fly diving flies.
2. The reason for external conditions
The degree of occurrence of bean root snake diving flies is also closely related to the external environmental conditions, especially temperature, they like to feed and mate between 20 ° C and 25 ° C, if the soil moisture in the field is high, it is more conducive to the feathering of adult insects. Of course, if the external environment becomes harsh, if there is a continuous drought or sudden cooling, they will also become unsuitable, and the insect population base will be reduced.
3. Defects in human prevention and control
There is no stubble rotation in the plots
Bean root snake diving fly is a pest that only harms soybean crops, to put it bluntly, it is only to eat soybeans, and will overwinter in the field soil in the form of pupae, if the same field is continuously planted with soybeans, then the egg base of the bean root snake diving fly will become larger and larger, which will lead to frequent occurrence of bean root snake diving flies.
Fertilization is not scientific and reasonable
Soybean growth and human body, the need to supplement a variety of nutrients, if the plant growth process is missing or excessive supplementation of a certain nutrient, it will lead to poor growth and development of soybean plants, weak seedlings, yellow leaves and other phenomena, so there are many disadvantages: one is easy to suffer from the harm of bean root snake diving flies, the second is poor recovery ability, that is, the pest is controlled, but it is difficult to restore the plant to a healthy state.
Lack of awareness of proactive prevention and control
Bean root snake diving fly is different from other insect pests, which from the seedling stage of soybeans began to harm, and is harmful to the roots of soybeans, if the farmer does not have the habit of seed mixing or early prevention, see the aboveground part of the plant lesions before starting to use drugs, then missed the best control period, resulting in serious occurrence of bean root snake diving flies.
The exact application time was not mastered
For the control of most pests, the general best control time is when the adults lay more eggs and when the larvae begin to hatch in large numbers, because the insects at that time are more concentrated, and the resistance of the hatching larvae is low, and the bean root snake fly is no exception, and the adult insects like to mate and lay eggs in the morning and evening, the peak period of egg laying is in mid-June, and then to the end of the month is the peak of larval hatching, these periods are the best time to apply the drug, but many farmers are not clear.
Indiscriminately using drugs to kill the natural enemy of the bean root snake fly
The natural enemy of the bean root snake diving fly is the bean root snake diving fly, which takes the bean root snake diving fly, the bean stalk black diving fly and other flies as food, if the bean root snake diving fly in the field insect mouth base is not large, the bean root snake diving fly can prey on the adult and larvae of the bean root snake diving fly, which can effectively control the occurrence base of the bean root snake diving fly, but the habit of using highly toxic broad-spectrum agents to kill insects, resulting in a small number of natural enemies are also implicated.
<h1 class="pgc-h-decimal" data-index="03" > are also flies, how to distinguish between "bean root snake diving fly" and "bean stem black diving fly" in the field? </h1>
Bean root snake diving fly and bean stalk black diving fly are important pests on soybeans, both of which can make the aboveground part of the plant show yellowing leaves, short plants, and finally die after both endanger soybeans, so learn to distinguish in order to prevent and control as soon as possible.
1. The difference in the body shape of the adult insect
Although the size of the bean root snake diver and the bean root snake diver fly are similar, a closer look will still find that they have differences: first, the body color of the bean root snake diver fly is all black, while the body color of the bean root snake diver fly is black and bright; secondly, the compound eye of the bean root snake diver is black brown, and the compound eye of the bean root snake diver is dark red; finally, the abdomen of the bean root snake diver has a yellow-green, metal-like luster, and the abdomen of the bean root snake diver is blue-green metallic.
2. Different parts of the hazard
The bean root snake diving fly mainly uses larvae to drill moths into the root system of soybean seedlings for feeding, causing the root system to appear cracked and thickened, causing the root system to weaken, while the bean stalk black diving fly mainly uses larvae to harm the stem of soybean, and the borer eats the inside of the stem to cause hollowness, causing the stem base to become brown and necrotic.
<h1 class="pgc-h-decimal" data-index="04" > "bean root snake fly" is actually not difficult to fight, the key is to be flexible and coordinated prevention</h1>
1, agricultural prevention and control is still "C position"
The field should be planted in a one-year-by-year manner: in addition to reducing the accumulation of bean root snake fly eggs, it also reduces the accumulation of other pathogens and insect eggs, reduces the occurrence of soybean diseases and insect pests and the difficulty of prevention and control, and achieves more in one fell swoop.
Appropriate early soybean sowing time: the occurrence of bean root snake diving fly and external climatic conditions have a close relationship, to put it bluntly, the occurrence and prevalence of bean root snake diving fly has formed a certain law, that is, when to feather, what time to mate and other time are relatively fixed, appropriate early sowing, can make soybean healthy growth, root system developed, so that the seedling stage and the bean root snake diving fly peak period staggered, reduce harm.
Scientific and reasonable fertilization: for the planting of soybeans need to be based on the fertilizer characteristics of its different growth stages for precise fertilization, especially the base fertilizer and seedling fertilizer should be applied sufficiently, enough, more use of organic fertilizer and microbial bacterial fertilizer can promote the growth of seedling roots, so that the root system is developed, and eventually grow into a robust plant, strong resistance to diseases and insects.
2, biological control is "auxiliary"
For the prevention and control of bean root snake fly, in addition to doing a good job in agricultural basic control measures, natural enemies can also be used for auxiliary control, and the main measures are 2 points:
The use of chemical agents with low toxicity to bees and high efficiency against pests, so as to avoid accidental injury to natural enemies in the field away from the jaw cocoon bees, and from then on, the control of bean root snake flies has one more helper;
In the early stages of the bean root snake fly, artificially raised cocooned bees can be released for control, and it should be noted that during the release of natural enemies, there is no need to use chemical agents for control, unless the pests cannot be controlled.
3. Chemical control is the last "line of defense" to protect soybeans
For the control of bean root snake fly, in the case of a serious outbreak of pests, the use of drug control is the last line of defense to keep soybeans, so it is necessary to prevent it in advance.
Soybeans before sowing
Soybeans can be stirred with a pound of seeds using 30% high-efficiency cyspermethrin and thiamethoxen microcapsulant suspension 20g before sowing, that is, seed mixing; or when furrowing, use 2% thiothiazine granules to spread, which can effectively control the harm of bean root snake flies to seedlings and protect the healthy growth of the root system.
Soybean growing season
In the growth period of soybeans, the main control is to prevent the feathered adults and newly hatched larvae from entering the roots of the plant, so it is necessary to grasp the appropriate control period and spraying time to prevent it efficiently.
Suitable period for control: mid-June to the end of June every year (peak period of adult egg laying, peak period of larval hatching)
Time for spraying: 8:00 a.m., 4:00 p.m
Recommended agents: Spirosamine wettable powder, cypermethrin emulsion, high-efficiency cypermethrin emulsion, avermectin emulsion, octylthion emulsion, Lesben emulsion, etc., reasonable rotation, continuous spray 2 times to achieve better prevention.
In short, the bean root snake fly is a harmful pest that needs to be actively controlled. Of course, there are many factors that cause the outbreak of bean root snake diving flies, and the majority of farmers need to improve their awareness of prevention and control, and need to combine the situation of their own fields and find out the causes, so as to reduce the occurrence of bean root snake diving flies.