On Dec. 17, 2024, scientists from Hiroshima University announced they had mapped near-gap-free and near-error-free genomes of a susceptible bed bug strain and a superstrain around 20,000 times more insecticide-resistant, offering the broadest look yet at the full scope of their resistance mutations.

The research team mapped genomes of susceptible and resistant bed bug strains from Japan to address this gap. They obtained susceptible strains descended from wild bed bugs (Cimex lectularius) collected 68 years ago in fields at Isahaya City, Nagasaki. Meanwhile, the resistant strains were bred from specimens collected from a Hiroshima City hotel in 2010. Their tests revealed that the resistant samples had 19,859-fold stronger resistance to pyrethroids — the most commonly used insecticide for bed bug control — exceeding levels seen in many previously identified superstrains.

Although there is no evidence that bed bugs transmit diseases to humans, their bites can cause itchy rashes and secondary skin infections. Widespread use of insecticides, including the now-banned DDT, nearly wiped out populations of these blood-sucking insects by the 1960s, making infestations rare. But over the past 20 years, the world has witnessed their resurgence, partly due to resistance mutations they developed against these insecticides. Their findings were published in the journal Insects.