Ellen Phiddian
Cosmos science journalist
Bed bugs are notoriously difficult to remove once they’ve moved in – and they’re getting more difficult, thanks to their evolving resistance to insecticides.
A team of researchers has mapped the genomes of bed bug strains, aiming to find out why a “superstrain” has become 20,000 times more resistant to treatment.
The study is published in Insects.
Bed bugs (Cimex lectularius and Cimex hemipterus) have spread rapidly around the world in the past 20 years. While there’s no evidence they transmit disease, the bug bites can be extremely irritating and cause secondary infections.
In this study, researchers collected DNA from 2 bed bug sources. One population, judged vulnerable to pesticides, had been originally collected from fields in Nagasaki, Japan, but maintained in a lab for 68 years. The other population was collected from a hotel in Hiroshima, Japan, in 2010.
The Hiroshima population was 19,859 times stronger at resisting pyrethoids, which are most commonly used to control bed bug populations.
The researchers looked at the genomes of each population, to spot mutations and differences.
“By comparing the amino acid sequences between the susceptible and resistant bed bugs, we identified 729 transcripts with resistance-specific mutations,” says first author Dr Kouhei Toga, a postdoctoral researcher at the Laboratory of Genome Informatics from Hiroshima University, Japan.
“These included genes related to DNA damage response, cell cycle regulation, insulin metabolism, and lysosome functions.
“This suggests these molecular pathways may play a role in the development of pyrethroid resistance in bed bugs.”
The genetic information could be used to develop more effective pest control measures, according to the researchers.
They could also help to monitor wild populations for signs of insecticide resistance.
“We identified a large number of genes likely involved in insecticide resistance, many of which have not been previously reported as being associated with resistance in bedbugs,” says Toga.
“Genome editing of these genes could provide valuable insights into the evolution and mechanisms of insecticide resistance.”
