Pests can make returning from a holiday a nightmare, especially when it comes to bed bugs. These parasites, which hide in beds and furniture and feed on human blood while sleeping, are extremely difficult to eradicate. A new study has finally shed light on one of the main reasons for this resistance.
A team of biologists from Hiroshima University published their findings in the journal Insectshas completed the sequencing of the genome of common bed bug (Cimex lectularius). This mapping, described as almost completely error-free, revealed specific genetic mutations that make bedbugs highly resistant to insecticides.
The researchers analyzed two strains of bedbugs: one sensitive to insecticides and the other resistant. The former derived from samples collected more than 60 years ago, while the latter came from a population infesting a hotel in 2010. This comparison allowed us to observe the genetic evolution of bedbugs over time, showing how much they have adapted to survive.
The results were surprising: using pyrethroids, a common insecticide, the researchers found that modern strains are 20,000 times more resistant compared to historical samples. Kouhei Toga, lead author of the study, explained: “We identified 729 gene transcripts with specific mutations associated with resistance.”
How bedbugs win the battle against insecticides
Bedbug resistance is a complex phenomenon. Genetic mutations can lead bedbugs to produce enzymes capable of neutralizing the insecticide or to develop thicker exoskeletons, which prevent the poison from penetrating. This evolutionary process contributed to their rebirth, after they were almost eliminated in the 20th century thanks to DDT, a pesticide banned in the 1970s.
In recent decades, bedbugs have started to proliferate again, equipped with a sort of “genetic armor”. As Chow-Yang Lee, a professor at the University of California, Riverside, explains: “You can dip them directly into the insecticide, and they will still survive.”
Preventing and fighting bed bugs: practical advice
Despite the resistance, an effective method against bedbugs remains heat treatment. Bringing the temperature of infested environments up to 57°C can kill both insects and their eggs. However, this approach is not foolproof: if the heat does not reach every infested area, some bedbugs may survive.
Prevention is therefore essential. When traveling, it is advisable keep luggage off the groundon special supports or even in the bathtub, to prevent bedbugs from entering. When you return home, it’s good practice to unpack in a garage or insulated room, wash your clothes immediately on high heat, and dry them on the hottest setting on your dryer.
