The desert locust strikes again, how to deal with it? According to media reports, in May 2020, when countries around the world are busy responding to the threat of coronavirus, East African countries are facing a new problem—a large scale locust attack again. The scale of the locust plague was 20 times the first disaster in early 2020. . Desert locusts swept Africa, West Asia, and South Asia. The Food and Agriculture Organization of the United Nations once again released information that the second wave of locust plagues has caused about 20 million people in six East African countries (Ethiopia, Kenya, Somalia, South Sudan, Uganda and Tanzania) to fall into a severe food crisis. In addition, Yemen has also been attacked by locusts, and 15 million people in the country face the same situation. Large-scale locust disasters have occurred in many countries again. In this fight against pests, in addition to traditional chemical pesticides and other pest control measures, biological pesticides are gradually becoming a rising star in the insecticide industry. So, what technologies are used in the design of biological pesticides, and how do these pesticides eliminate locusts? Biological pesticides refer to living organisms and their metabolites, including microbial pesticides, botanical pesticides, natural enemies, etc. Among the biological pesticides used to control locusts, there are more microbial pesticides that are harmless to the environment, including fungi, bacteria, viruses, and protozoa. These microorganisms are derived from nature. For example, the commonly used Metarhizium anisopliae, which is an important entomogenous fungus, is extracted from the body of locusts that have the “flu”. Compared with chemical pesticides, many biological pesticides have a slower effect. Generally, it takes 1 to 2 weeks to start acting on pests. In order to improve the speed and effectiveness of the prevention and control of these agents, researchers use aerospace mutagenesis, genetic engineering, molecular breeding and other technologies to improve their virulence against locusts. After locusts eat or come into contact with these fungi, they get "influenza", and this "flu" will continue, reducing the reproduction rate, attack power and lifespan of locusts. Judging from the current statistical data, the control effect of this control method can reach up to 8 to 10 years. No single technology can solve the problem of locust plague. Therefore, it is necessary to combine biological control, chemical control, and ecological management to achieve long-term control of pest populations. Especially in medium and high-density areas, continuous prevention and control measures based on biological pesticides can be used to make these microorganisms form a disease epidemic in dense locust populations, and through migration and carrying each other, the continuous control of locusts can be achieved, so that disasters are no longer spread.
In addition to anti-locust insecticides such as fungi and bacteria, there are many types of biological insecticides on the market, such as Bacillus thuringiensis, viruses, and plant-derived insecticides. Among them, Bacillus thuringiensis insecticide, also known as Bt insecticide, is currently the most successful insecticide for biopesticide research and development and application, accounting for more than 90% of the total amount of biopesticides, which can control more than 150 lepidopteran pests. In comparison, biological pesticides have three major advantages. One is a long validity period. Compared with chemical pesticides, biological pesticides are less toxic or non-toxic and have a long duration of action. Biological pesticides also have a major advantage, that is, they have good targets and strong selectivity. They are only effective against one or one type of pests, and have no effect on nontarget pests. At the same time, they are harmless to humans, birds, fish, and silkworms. In addition, it has no residue and is environmentally friendly, which is also one of the advantages of biological pesticides. The dosage of biological pesticides is relatively small, and pests are not easy to develop resistance. There is no report on the development of resistance of pests after the use of biological pesticides. And they come from soil, plants or insects in nature, so they can avoid environmental pollution caused by chemical pesticides.