This summer’s heatwave could harm British bumblebees, according to a new analysis of long-dead bee collections kept in museums.
Bumblebees have endured stress for nearly a century, possibly due to the hotter, wetter conditions the study suggests, but new DNA techniques could help focus future conservation efforts.
Researchers from Imperial College London and the Natural History Museum teamed up with four other Scottish and British museums to analyze their bumblebee collections looking for variations in body shape.
When wasps are stressed, it has an impact on their developing offspring. Their bodies – specifically the wings – became asymmetrical. By comparing the degree of asymmetry in four species of wasp with climate records over the past 120 years, the researchers found that stress appears to be linked to climate conditions.
Dr Richard Gill of Imperial College London, who led the study, said: “When conditions are warm and relatively humid, stress is higher.
Climate change is already known to have an impact on the geographical distribution of some species of wasp, but this is the first study to show its potential impact on insects that lived in the past.
Dr Gill said: “The museum specimens are almost like little time machines that monitor that tension.
The researchers found that for the species they studied, stress levels were lowest around 1925. Since then, overall stress levels have increased – with higher levels found during wetter and warmer than average years.
According to the team, why things started to change around 1925 remains unclear. One possibility is that it is related to changes in agricultural practices and the use of pesticides known to be responsible for the decline of insects in the late 20th century.
That is pure speculation, Dr Gill insisted. However, a parallel study also published today could help identify threats to wasps and broader insect decline by extracting DNA from museum specimens.
Borrowing techniques used to study the ancient DNA of Neanderthals and woolly mammoths, Professor Ian Barnes of the Natural History Museum was able to retrieve genetic data from wasp collections dry, dusty drawing.
Taking just a single leg from about 100 bee samples, his team was able to reconstruct the genomes of long-dead bees – a valuable tool when compared to the species’ genetic code. bees live today.
Professor Barnes said: “A genome constitutes a vast amount of information about a past situation.
By matching historical data on things like climate, pesticide use and changes in land use with the genetics of bees at the time, researchers can see populations of how bees respond or determine whether particular species are more susceptible to change than others.
“We can look for changes in diversity or signals of adaptation,” says Dr. “It can reveal things we can’t see outside of a bee.”
According to the researchers, getting a picture of how bees have coped with stress in the past could help focus future conservation efforts.
The work also highlights the importance of museums for forward-looking research.
Dr Gill said: “These museums have all the secrets, just unlock them.