To save the bees, we’ve now seen a lot of communities planting more bee gardens, encouragement to eliminate pesticides, and maintain beehives.  

While those actions help, it’s not nearly enough, especially for threatened bees like the rusty patched bumblebee. 

However, science is trying to help yet again: researchers have acquired a detailed map of a North American bee species’ genome. This may help save the essential pollinator from extinction.   

The U.S. Department of Agriculture’s Agricultural Research Service (ARS) and the U.S. Fish and Wildlife Service have released the newly completed genome map of the rusty patched bumblebee, or Bombus affinis. 

With this, the researchers hope that analyzing bee genomes will provide new insight on how to save the bees, which consequently help develop resources for conservation. 

Entomologist Jonathan B. Uhaud Koch of the ARS said, “Having this high-quality genome will support the identification of genetic differences between rusty patched bumble bee populations that appear to be doing well versus where they are in decline.” 

Rusty patched bumblebee sequencing 

The genomic sequencing of the endangered bumblebee is a part of the Beenome 100 project which gives conservationists the tools they need to better preserve the pollinators. 

Beenome 100 itself is a collaboration between the ARS and the University of Illinois that aims to create a library of high-quality, detailed maps of 100 or more U.S. bee species as a conservation aid. 

In a statement, Koch said, “We used a small piece of abdominal tissue from a single male collected from a nest in Minnesota, which, given the endangered status of the rusty patched bumble bee, seemed like a very good idea. 

“It’s only with the most cutting-edge equipment that you could resolve an entire genome of 15,252 genes and 18 chromosomes from a tiny bit of one bumble bee.” 

The rusty patched bumblebee was federally listed as endangered in 2017 and received a finalized plan for recovery in 2021.  

Native to the eastern and upper Midwest of the U.S. and parts of southern Canada the bumblebee’s range has now been limited to isolated scatterings across only a couple U.S. states and Canadian provinces. 

Even though people regularly spot these bumblebees near Minnesota and Wisconsin, their populations have approximately declined by 87% from historical numbers. 

As we know, pollinators like these fluffy bees are essential to maintain biodiversity and sustain habitats for other endangered animals.  

At the same time, they help us humans too, as these bees are an important pollinator of crops like cranberries, apples, onions and alfalfa, along with wildflowers like milkweed and bergamot. 

 

 

Habitat getting more and more hostile 

Environmentalists have observed and documented the many threats that are facing the rusty patched bumblebee and other endangered bee species. 

Those threats include harmful chemicals used in modern agriculture, loss of habitat due to reduced biodiversity, exposure to pesticides, and disease and parasites. 

For the rusty patched bumblebee exclusively, they’ve also been under the threat of a fungal pathogen called Varimorpha bombi. The bees are particularly vulnerable to the pathogen, as it has significantly affected colony health and reproductive rates. 

According to researchers, 4.5% of the DNA sequenced came from the pathogen. 

“That’s a massive amount of genetic information from the bee tissue sample to be associated with Varimorpha bombi. It demonstrates how pervasive the pathogen is,” Koch said. 

Moreover, new research from Lund University in Sweden discovered that bumblebee queens in those areas have been affected by a warmer climate and a changing agricultural landscape. 

Bumblebees in Scandinavia take off earlier now 

The Lund University research found that in the arrival of spring, the queens are flying earlier in the year. 

Maria Blasi Romero at Lund University said, “We risk losing additional bumblebee species, and having less pollination of crops and wild plants” 

When the ground warms up as spring arrives, the queens, which are the only ones that survive winter, wake up from hibernation. After that, they spend a couple of weeks finding a place to nest, where they can lay eggs and start a colony. 

Unfortunately, warmer temperatures make them wake up earlier. In Sweden, according to the researchers, the first flight occurs on average five days earlier than twenty years ago. 

“Across Sweden, we see that the increased temperatures due to climate change clearly affect when the queens wake up and fly to find a new nest,” Romero said. 

As mentioned, the queens’ early take-offs are also the result of intensive farming. The researchers have used the Lund Biological Museum’s collection to examine bumblebee queens as far back as 117 years ago, in different areas of southern Sweden. 

The data shows that the first bumblebee flight in intensively farmed landscapes now takes place about fourteen days earlier than over a century ago. 

According to the Lund University researchers, the major change in the examined landscapes during the past century is the loss of grassland habitats, such as meadows and permanently grazed pastures. 

Today, large agricultural fields dominate and often only a few different crops are grown. This has led to a general decline of farmland biodiversity compared to the more diverse landscapes decades before. 

 

 

The thing about taking off earlier 

Some may ask, “What’s wrong with taking off just 5 to 10 days earlier?” 

Well, after researching ten bumblebee species, the researchers found that the species that already used to fly earliest in the season have become even earlier flyers, while the species that emerge later in the season have not changed their flight season. 

This can lead to a potential risk of a poor match between the activity periods of flowering plants and bumblebees, which makes the bumblebees not getting enough food. 

Also, with earlier take-offs and varying microclimatic conditions in today’s agricultural landscape, bumblebee queens don’t have enough food during the flight period after hibernation. That alone can increase the risk of local extinction. 

Another researcher at Lund University Anna S. Persson said, “This could also lead to a decline in the number of bumblebees overall and that would have consequences for the pollination of crops and the functioning of ecosystems. Bumblebees are important pollinators, especially in northern latitudes such as in Scandinavia.” 

Researcher Romain Carrié said, “Climate change and changing land use are two of the biggest threats to biological diversity. Different species respond differently to these changes, so it is important to know more about how and why that is. There are winners and there are losers among species.” 

Helping the bumblebees 

The Lund University researchers have highlighted and suggested several measures that could reduce the effects of climate warming on pollinators and increase their access to flowering plants. 

According to them, some of the ways are: preserving natural grasslands such as natural pastures, late season mowing at roadsides after flowering period, flower hedge designing that favors pollinators, and increasing the sow of clover-rich leys that are partly allowed to flower. 

As for the genome sequencing, well, the US research suggests that the identification of specific bees’ genome can help environmentalists prioritize conservation efforts to prevent further loss of the rusty patched bumblebee. 

Koch said, “This may give us a handle on identifying the genes that give the more capable population its flexibility to deal with its environment. We may also gain a better understanding of the genetic basis of bumble bee behavior, physiology and adaptation to changing environmental conditions.” 

Of course, we can only wait and see as to how the genome sequencing will play out. But the new research definitely gives us some hope for the endangered bumblebees. 

Meanwhile, we can do the things that the Lund University researchers have suggested and keep helping the bees in ways we can or already know. 

 

Sources

https://www.courthousenews.com/genomic-sequencing-could-pull-bees-back-from-brink/  

https://www.sciencedaily.com/releases/2023/03/230302093400.htm