A new study conducted by researchers from New Mexico State University and Virginia Tech reveals that bedbugs are getting stronger - in particular, they have developed resistance to the neonicotinoid insecticides, also known as neonics. Neonics are the most widely used type of insecticides today and this study suggests that alternative pesticides might need to be developed to effectively combat bedbugs in the future.
The team studied bedbugs gathered from homes in Cincinnati and Michigan and tested their ability to withstand four different neonics: acetamiprid, dinotefuran, imidacloprid, and thiamethoxam. Additionally, they applied these neonics to a bed bug colony that was housed by one of the researchers for more than 30 years with no exposure to insecticides as well as a pyrethroid-resistant population from New Jersey that had never been exposed to neonics.
The findings showed that the colony with no insecticide exposure died even when exposed to small amounts of neonics, while the New Jersey bugs held up slightly better. The team found that this resistance stemmed from their "detoxifying enzymes," which are used by bed bugs to fight insecticides and were more abundant in the New Jersey group.
"Elevated levels of detoxifying enzymes induced by other classes of insecticides might affect the performance of newer insecticides," Alvaro Romero, who participated in the research, said in a press release.
Furthermore, the bed bugs collected from Cincinnati and Michigan showed even higher levels of neonic resistance due to the fact that they lived during a time when pyrethroids and neonicotinoids were common in the U.S. market.
"Companies need to be vigilant for hints of declining performance of products that contain neonicotinoids," Romero said. "For example, bed bugs persisting on previously treated surfaces might be an indication of resistance. In these cases, laboratory confirmation of resistance is advised, and if resistance is detected, products with different modes of action need to be considered, along with the use of non-chemical methods."
The findings were published in the Jan. 28 issue of the Journal of Medical Entomology.
