A beige predator mite less than a tenth the size of a sesame can prey on a red spider that is two or three times larger than itself; 2500 predatory mites in a small bag can make red spiders, yellow spiders and other pests on a citrus tree disappear...
At the National Citrus Engineering Research Center of Southwest University, researcher Ran Chun, inventor of the drug-resistant predatory mite, is reviewing the artificial breeding of a new batch of predatory mites. This kind of predator mite, which is almost invisible to the naked eye, can prey on important citrus pests - red and yellow spiders, Ran Chun through more than ten years of research, selected and bred 3 new strains of resistant predator mites, created a factory efficient breeding and field release technology of resistant predator mites, and took the lead in realizing the industrial application of resistant predator mites in the world.
A type of predatory mite - Chilean mite (source network)
Let the citrus no longer use pesticides to deworm
Citrus is the most important cash crop in the world and the fruit with the largest cultivation area and yield in China. However, due to the fruit hanging period of citrus for more than 7 months, there are many kinds of diseases and insect pests that harm young leaves, young branches and young fruits, especially red spiders, yellow spiders and other pests, which will greatly reduce the yield and quality of fruits. Therefore, chemical pesticides need to be used in production for high-frequency spraying to eliminate insect pests, which often leads to excessive pesticide residues in orange fruit.
Citrus red spider
The biological control method of killing pests by using the attributes of insect natural enemies is a green environmental protection method advocated by the world's agricultural field. After research, it has been found that there are more than 120 species of natural enemies of the citrus pest red spider, of which more than 45 species of predator mites, and the promotion and use of artificially bred and obvious predatory mites can be effectively used to control citrus pests, thereby reducing the application of pesticides.
However, this predatory mite, which can prey on pests, also has a fatal weakness - it is easily killed by chemical pesticides, which has become the number one difficulty in the large-scale promotion of predatory mites. To this end, since 2008, Ran Chun undertook the National Agricultural Science and Technology Achievement Transformation Fund Project "Artificial Breeding and Production of Resistant Predatory Mites and Demonstration Application of Orange Orchards", and carried out in-depth research around drug-resistant predatory mites.
"Ordinary predatory mites (pasteurized neo-small mites) are almost not chemically resistant, and fruit growers will cause a large number of deaths when spraying pesticides on citrus to control other pests, and how to breed new varieties with drug resistance and mass production are all problems, and they have not been solved internationally." Ran Chun said that in order to be able to breed resistant predatory mites, he led the team to finally breed 3 new strains of pasteurized new small mites with a resistance multiple of more than 500 times.
Pasteuris neo-sycamore (source network)
Realize the industrialization of resistant predatory mites
In the production workshop of resistant predatory mites in the National Citrus Engineering and Technology Research Center, there is no rumbling machine sound, no assembly line, and white plastic boxes are neatly placed on the shelves, like a warehouse. However, the box contains a feed recipe for cultivating predator mites, and a single box can produce 100 bags of resistant predator mites per day. This is the first time in the world that the industrialization of resistant predator mites has been realized.
It is not easy to realize the industrialization of research results, because "mites" are organisms, and there are more difficulties that need to be broken. Ran Chun led the team to establish a drug-resistant molecular labeling technology, and found that the drug-resistant predator mites did not have a decrease in reproductive rate and predatory capacity with the increase of resistance, and could be commercially produced and applied in a large area.
Ran Chun introduced that through the research, they clarified the most suitable temperature and humidity for the growth and development of predatory mites, optimized the large-scale breeding process of drug-resistant predatory mites, established an efficient breeding technology for resistant predatory mites, and formed production technical regulations. At the same time, in accordance with the requirements of the achievement transformation project, they built a pilot line for the production of predator mites, with a production workshop of 3,000 square meters and an annual production capacity of 30 million bags.
It is understood that although other countries are also studying predatory mites, it is rare to breed high-resistance predatory mites, let alone industrialized. Ran Chun's team took the lead in the international realization of the industrialization of resistant predatory mites, which greatly improved the effect of this green environmental protection pest control and was promoted on a large scale in China's citrus industry.
Rapid plant construction and conversion in different regions
Ran Chun said that the release of predator mites only needs once a year to achieve the control of red and yellow spiders throughout the year, which only needs 50-60 yuan an acre, not only has no problem of pesticide residues, but also the cost is much lower than the use of chemical pesticides for control. These advantages also provide a good basic condition for the large-scale transformation and application of this achievement.
Ran Chun led the project team to establish a field release technology for predatory mites that adapts to different citrus varieties, different geographical conditions, and different pest bases. Established a production and promotion model according to the order, "because the survival period of mites is very short, can not be stocked for a long time, so we are producing according to the order, at the same time, through the transfer of technology, we can quickly build factories in different regions for production, provide products nearby, and meet the requirements of a short time." Ran Chun explained.
At present, more than 20 core demonstration bases have been established in the main citrus producing areas of Sichuan, Chongqing, Yunnan and other provinces and cities, with a demonstration area of 10,000 mu, a cumulative promotion of 10 million mu, farmers' income increased by more than 20 billion yuan, reduced the amount of chemical pesticides applied in citrus orchards by more than 50%, improved the quality of citrus fruits, and more than 100 cooperatives have achieved green food certification through this biological control method.
Source: Science and Technology Daily