A new study conducted in the United Kingdom determined that climate change is linked to stress in bumblebees and other insect pollinators over the past 100 years. Facing decline in recent years, the study found that four UK bumblebee species showed signs of stress in increasingly hotter and wetter conditions caused by changes in climate.
While bumblebees do not convert nectar into honey like honeybees, the different species are “essential pollinators for many wildflowers and agricultural crops like sunflowers, cranberries, blueberries and tomatoes,” EcoWatch reported.
The study, which was published in the Journal of Animal Ecology, “used ancient DNA techniques to sequence bumblebee genomes dating back over 100 years and showed that “each bee species displayed a consistently higher proxy of stress in the latter half of the century,” according to a press release.
“With hotter and wetter conditions predicted to place bumblebees under higher stress, the fact these conditions will become more frequent under climate change means bumblebees may be in for a rough time over the 21st century,” Dr. Richard Gill, senior author from the Department of Life Sciences (Silwood Park) at Imperial, said.
Scientists from Imperial College London and the Natural History Museum published two concurrent papers that analyzed the morphology (body shapes) of UK bumblebee populations dating back to 1900 by using digital images to investigate “the asymmetry in bumblebee wings as an indicator of stress,” according to the study.
“High asymmetry (very differently shaped right and left wings) indicates the bees experienced stress during development—an external factor that affected their normal growth,” according to a press release. The results showed that UK bumblebee species were more stressed in the latter part of the century from its lowest point in 1925.
“By using a proxy of stress visible on the bee’s external anatomy and caused by stress during development just days or weeks before, we can look to more accurately track factors placing populations under pressure through historic space and time,” Aoife Cantwell-Jones, author from the Department of Life Sciences (Silwood Park) at Imperial, said.
Scientists from the Natural History Museum and the Earlham Institute will continue to study the new reference genome from the DNA preservation of a single bee leg from each of the bees studied to determine how the reported stress may lead to genetic diversity loss.
“One of the main problems with museum collections is that the quality of DNA can be very variable, making it difficult to predict which type of analyses we should do,” Professor Ian Barnes, senior author from the Natural History Museum, said. “We now have a much better idea about DNA preservation in insect collections, which is a massive boost to our ongoing work to understand the history and future of insect populations.”
From the study, researchers will now use this data to “study how bee genomes have changed over time, gaining an understanding of how whole populations have adapted—or not—to changing environments.”
“Our goal is to better understand responses to specific environmental factors and learn from the past to predict the future,” Dr Andres Arce, now at the University of Suffolk, said. We hope to be able to forecast where and when bumblebees will be most at risk and target effective conservation action.”