Bed bugs found in homes in Cincinnati and throughout Michigan were recently found to be highly resistant to neonicotinoid insecticides, which are widely used to tamp down infestations.
According to Richard Pollack, an entomologist and instructor at Harvard T.H. Chan School of Public Health who was not involved in the study, it’s not unexpected for the bugs to develop resistance to a particular insecticide. In a February 23, 2016 Forbes article, he said that insecticides can be incredibly effective for decades at a time, but that bed bugs have a workaround—if even a small percentage of them are resistant, those bugs will survive and reproduce, eventually supplanting the more vulnerable bugs.
Figuring out ways to get rid of bed bugs is “a constant arms race,” Pollack said. “We find something new, it works, and then they use Mother Nature’s laboratory to come up with ways to get around it.” However, he added that even if one insecticide stops working, there’s usually another one that will help.