For over 60,000 years, bed bugs have had a unique relationship with humans, which is unlike their ancestors that remained on bats. Researchers at Virginia Tech have compared the genome of two distinct lineages of bed bugs and found that the human-associated lineage has thrived in cities, following a demographic pattern similar to humans.
The study, published in Biology Letters, suggests that this lineage may be the first true urban pest. The researchers analyzed changes in effective population size, which indicates the number of breeding individuals contributing to the next generation. They found that the historical and evolutionary symbiotic relationship between humans and bed bugs can inform models predicting the spread of pests and diseases under urban expansion.
The team discovered that the human-associated lineage recovered and its effective population increased after large human settlements expanded into cities around 12,000 years ago. This growth is attributed to the early establishment of modern human populations in caves and their subsequent move into cities. The researchers are now focusing on studying the evolutionary alterations of this lineage compared to its bat-associated counterpart.
The team also found that bed bugs were nearly eradicated by DDT, but they started reappearing within five years due to pesticide resistance. Further research is being conducted to investigate a gene mutation contributing to this resistance and its relevance to the genomic evolution of bed bugs.
This study provides insights into the co-evolution of humans and pests during urban expansion and may help identify traits that contributed to the emergence of urban pests like bed bugs.
Source: https://www.futurity.org/bed-bugs-genome-3282962