Almost disappeared, bedbugs have made unwelcome returns over the past two decades, spreading homes and hotels around the world and bringing all kinds of health and comfort issues. While they are not proven to spread the disease, bed bugs can cause itchy skin, allergic reactions and psychological stress. The main reason for their revival is their increased resistance to commonly used pesticides, which makes them difficult to eliminate. Until recently, scientists had limited information on the genetic causes of this resistance, as the complete DNA of resistant bed bugs has not been studied.
Dr. Kouhei Toga and Professor Hidemasa Bono from Hiroshima University have made significant contributions in this field. Their study, published in the journal Insect, compares the full genetic information of the resistant and non-resistant strains of the common bed bug cimex lenticularius. Using advanced DNA sequencing tools, which enable researchers to read the complete genetic code of an organism, the team carefully mapped the types of genomes (full DNA instructions) and discovered specific genetic changes related to resistance.
One of their most striking findings is the extremely high resistance in the Hiroshima strain. This strain is more resistant to commonly used insecticides called permethrin than non-resistant strains. Such a huge difference points to a significant change in genetic levels. Fortunately, the quality of DNA sequences in both strains is equally high, making it easier for the team to compare them side by side.
Dr. Toga and Professor Bono have discovered hundreds of copies of genes called transcripts, which are messages replicated from DNA that can help the body produce proteins, and these changes are against changes unique to insects. Some of these involved genes are known to be associated with resistance, such as those involving control of neural signals or breaking down harmful chemicals. “These mutations can alter gene function and lead to pesticide resistance,” explains Professor Bono. They also discovered new mutations in genes that were previously not linked to resistance – these genes help repair damaged DNA, control how cells divide and manage how the body uses energy.
To explore what these changes might mean, the team looked at how these genomes work together in the body. They found that several key physical processes may play a role in resistance. These include how cells fix DNA damage, cell growth and division, how to process energy and how to process waste inside the cell. “DNA damage response, cell cycle regulation, insulin metabolism and lysosomes are associated with the development of pyrethroid resistance,” Dr. Toga notes. “DNA damage response refers to the way the body detects and repairs damaged genetic material. Cell cycle regulation controls when and how cells grow and reproduce. Insulin metabolism helps regulate energy use and storage, while lysosomes are the structure in which waste is broken down in cells. These findings suggest that insecticide resistance may be more complex than previously thought to be physical functions.
These findings have important practical implications. Not only can they help scientists better understand how resistance develops, they also open up new ways to test and resist resistance. Scientists can now use gene editing tools that allow DNA to make precise changes to study the exact role of these genetic changes, which may lead to smarter pest control strategies. Expanding the range of genes monitored in pest populations may also make resistance tests more accurate and informative.
Finally, Dr. Toga and Professor Bono’s research mark an important step in the fight against bed bugs. By identifying the genetic details that helped these pests survive pesticide treatments, scientists can now better show it. As resistant strains continue to spread, this knowledge is critical to establishing long-term, effective and scientifically based approaches to pest control.
Journal Reference
Toga K., Kimoto F., Fujii H., Bono H. “Genome searches for gene mutations may confer resistance to insecticides in the common bed bug cimex lenticularius.” Insect, 2024; 15 (737). doi:
About the Author
Dr. Kouhei Toga He is a researcher specializing in genomic informatics and molecular biology. He is affiliated with Hiroshima University, and his work focuses on the genetic mechanisms of insecticide resistance and genomic evolution. With expertise in advanced DNA sequencing and bioinformatics, Dr. Toga aims to better understand how small genetic changes lead to significant shifts in organisms’ behavior and survival strategies.
Professor Hidemasa Bono He is the main figure in genomic informatics and biodata analysis of Hiroshima University. He is responsible for the initiative of the Center for Genomic Editing Innovation, focusing on decoding complex biological data to drive innovation in health and agricultural sciences. Professor Bono’s work bridge has cutting-edge technology for real-world applications, using powerful computing tools to reveal the hidden role of genes in resilience, disease, and adaptability. Toga and Professor Bono have helped shape the future of pest management and genetic research.
