- Researchers shed light on the complex evolutionary past of bedbugs.
- Study finds bedbugs have been parasitic companions with other species
aside from humans for more than 100 million years, and were around at the
same time as dinosaurs.
- Experts discover bedbugs are 50 million years older than bats – a
mammal that people had previously believed to be their first host.
- Findings will help us better understand how bedbugs evolved the traits
that make them effective pests, something that may help us understand new
ways of controlling them.
Bedbugs – some of the most unwanted human bed-mates – have been parasitic
companions with other species aside from humans for more than 100 million
years, walking the earth at the same time as dinosaurs.
Work by an international team of scientists, including the University of
Sheffield, compared the DNA of dozens of bedbug species in order to understand
the evolutionary relationships within the group as well as their relationship
with humans.
The team discovered that bedbugs are older than bats – a mammal that people
had previously believed to be their first host 50-60 million years ago. Bedbugs
in fact evolved around 50 million years earlier.
Bedbugs rank high among the list of most unwanted human bedfellows but
until now, little was known about when they first originated.
Experts have now discovered that the evolutionary history of bed bugs is
far more complex than previously thought and the critters were actually in
existence during the time of dinosaurs. More research is needed to find out
what their host was at that time, although current understanding suggests it’s
unlikely they fed on the blood of dinosaurs. This is because bed bugs and all
their relatives feed on animals that have a “home” – such as a bird’s nest, an
owl’s burrow, a bat’s roost or a human’s bed – a mode of life that dinosaurs
don’t seem to have adopted.
The team spent 15 years collecting samples from wild sites and museums
around the world, dodging bats and buffaloes in African caves infected with
Ebola and climbing cliffs to collect from bird nests in South East Asia.
Professor Mike Siva-Jothy from the University of Sheffield’s Department of
Animal and Plant Sciences, who was part of the team, said: “To think that the
pests that live in our beds today evolved more than 100 million years ago and
were walking the earth side by side with dinosaurs, was a revelation. It shows
that the evolutionary history of bed bugs is far more complex than we
previously thought.”
Dr Steffen Roth from the University Museum Bergen in Norway, who led the
study, added: “The first big surprise we found was that bedbugs are much older
than bats, which everyone assumed to be their first host. It was also
unexpected to see that evolutionary older bedbugs were already specialised on a
single host type, even though we don’t know what the host was at the time
when T. rex walked the earth.”
The study also reveals that a new species of bedbug conquers humans about
every half a million years: moreover that when bedbugs changed hosts, they
didn’t always become specialised on that new host and maintained the ability to
jump back to their original host. This demonstrates that while some bedbugs
become specialised, some remain generalists, jumping from host to host.
Professor Klaus Reinhardt, a bedbug researcher from Dresden University in
Germany, who co-led the study, said: “These species are the ones we can
reasonably expect to be the next ones drinking our blood, and it may not even
take half a million years, given that many more humans, livestock and pets that
live on earth now provide lots more opportunities.”
The team also found that the two major bedbug pests of humans – the common
and the tropical bedbug – are much older than humans. This contrasts with other
evidence that the evolution of ancient humans caused the split of other human
parasites into new species.
Professor Mike Siva-Jothy from the University of Sheffield, added: “These
findings will help us better understand how bedbugs evolved the traits that
make them effective pests – that will also help us find new ways of controlling
them.”
The researchers hope the findings will help create an evolutionary history
of an important group of insects, allowing us to understand how other insects
become carriers of disease, how they evolve to use different hosts and how they
develop novel traits. The aim is to help control insects effectively and
prevent the transmission of insect-vectored disease.
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