Most pesticides today are chemical pesticides. These chemical pesticides have become a problem overseas due to soil pollution and adverse effects on ecosystems. Chemical pesticides are concerned about their impact on the environment and human body, and expensive lawsuits have been filed overseas. In addition, the number of pollen-carrying bees and butterflies is decreasing due to chemical pesticides, which has led to a problem of reduced crop yields. In the 2021 Food System Strategy, the Ministry of Agriculture, Forestry and Fisheries set a goal of “halving the use of chemical pesticides by 2050.” The pesticides expected to achieve this goal are RNA (ribonucleic acid) pesticides, which use substances that carry the genetic information of living organisms. RNA is designed to suppress the activity of insects and mold that harm crops, and these RNA pesticides are applied to the agricultural field.
Tokyo University of Agriculture and Technology and others are achieving results with RNA (ribonucleic acid) pesticides. Development of a dream pesticide that can eliminate only targeted pests and is easily decomposed after being spread on farmland is progressing. Professor Takeshi Suzuki of Tokyo University of Agriculture and Technology has developed a technology that uses RNA to increase the appetite of beneficial mites that eat pests on vegetables. The mechanism used in this technology is called RNA interference. RNA interference binds to targeted substances in cells and disables their function. When the mites were fed food containing RNA, they ingested it and the RNA acted as intended. Many of the raw materials for chemical pesticides are derived from petroleum, which makes them vulnerable to geopolitical influences. There is a risk that prices will rise and imports will be delayed. In the future, agricultural technologies with low environmental impact will be even more required. RNA pesticides seem to be playing a part in this.
RNA-based technology has been put to practical use for medical purposes as a vaccine for COVID-19. In the United States, a US bio venture put RNA pesticides to practical use for the first time in 2024. This pesticide targeted the “collado beetle,” which is resistant to existing chemical pesticides. Bacteria were used to create RNA that is given to eggplant leaf beetle larvae that eat eggplant leaves. When the larvae were fed the RNA, cell death occurred in various parts of their bodies, and damage to leaves was reduced. This venture is also developing RNA to eliminate mites that parasitize honeybees. There are challenges here too. To popularize it as a pesticide would require quantities on an order of magnitude greater than those required for vaccines. Mass production and manufacturing costs are issues. When there are challenges, companies emerge to take on the challenge. One such company is the Japanese company Ajinomoto. Ajinomoto has developed the basic technology for mass production using amino acid fermentation. It is our hope that such technology will become more widespread.
