An accidental laboratory discovery has revealed that bedbugs are averse to water and moisture, a finding that could lead to new strategies for controlling the spread of these invasive insects. The study, published in the Journal of Ethology, highlights a previously unknown behaviour that may help in developing more effective pest control methods.
Bedbugs, scientifically known as Cimex lectularius, are blood-sucking insects that can quickly establish themselves in homes and are notoriously difficult to eliminate. Their global resurgence over the past 20 years, largely due to resistance to chemical pesticides, has prompted researchers to study their behaviour in search of alternative control measures.
The discovery was made by accident during routine lab work. Researchers at the University of California, Riverside were maintaining bedbug colonies in small vials with an artificial feeder filled with blood. When a membrane holding the blood was slightly damaged, blood soaked into a piece of paper inside the vial. Lead author Dong Hwan Choe observed that the bedbugs actively avoided the wet areas of the paper, even though they would normally feed on blood.
Further experiments showed that all bedbugs, regardless of age or sex, avoided wet surfaces. They often performed rapid U-turns to retreat from moist areas. The researchers believe this behaviour is linked to the insects' physical structure: their flat bodies and small breathing openings (spiracles) can become blocked if they come into contact with water, which poses a danger due to water's adhesive power.
Dr Choe suggested a simple solution for those who suspect bedbugs on their person: taking a bath. However, he noted that infestations in rooms or on beds require different approaches. The findings could inform new strategies for controlling bedbug infestations, potentially using moisture barriers or other water-based deterrents.
