Bees!

Welcome to the Earth and Nature blog!

I've been kicking around the idea of starting this blog for sometime. I've spent a lot of my time over the last two years working on a book about species extinction and our role in the loss of Earth's biodiversity (if you want to check that out its called Extinction in a Human World, its available on Amazon). Naturally in my research I came upon an incredible amount of information regarding a wide range of environmental issues, current and historical. Not only was this way more information than a single book could contain, but I found that new information comes available so often, that any book is almost out of date the moment it is published. So this blog is an attempt to share that information.

There is really no topic relating to nature, environmental science, etc. that I consider off limits, so there will be a wide variety of posts covering a wide range of topics relating to the environment and the threats to it. Hopefully many that you will find interesting. 

So on to the first subject. To be perfectly honest I had a lot of trouble deciding what a wanted to write about first. It's not that there is a lack of subjects that could be addressed. Pollution, climate change, resource consumption, that cluster of a train wreck in Ohio, the debate on green energy, electric cars, are windmills really killing whales? Honestly, where do I even start?  With spring on the horizon, and with its coming, the first flowers of the season, I thought it fitting to talk about bees.

A bumblebee feeds on a blue false indigo plant.      ©  T. Thomas Rathe

Bees, and pollinators in general, are vital creatures in the environment. Worldwide, 75% of all of our food crops are pollinated by animals, not to mention the countless other wild plants that rely on these pollinators. Bees and flowering plants have had this close relationship for over 100 million years continually evolving together in ways that benefit one another. Today there are more than 20,000 species of bees around the world and more than 4,000 in the U.S. Almost 950 of these are native to my home state of Colorado. Of course, this number excludes the honeybee that is not native to North America. Honeybees were brought here from Europe in the 1600s. While there has been lots of focus on the decline of honeybee populations and the colony collapse disorder that has been devastating them, curiously less focus has been placed on wild bee populations. While honeybees are very useful pollinators themselves, not to mention their prodigious honey production, they are typically not as effective as their wild cousins in pollinating and despite the prevalence of their managed colonies, 80% of all flowering plants worldwide are still pollinated by wild bees according to the USGS. It is then very worrisome that stark declines in wild bee populations have been observed. 

A number of studies have shown declines in native North American bees. One of the most concerning studies found that the populations of four common bumblebee species (Bombus occidentalis, B. pensylvanicus, B. affinis, and B. terricola) in the United States has declined by 96% in the last 20 years and their geographic ranges have contracted between 23 and 87%. This drop has been confirmed in a study from New Hampshire looking at 150 years worth of records from the University of New Hampshire Insect Collection. Populations for B. affinis saw sharp declines in the last 70 years until eventually disappearing altogether from the state. The same was seen for B. terricola whose relative abundance dropped 96.4%, but at the present can still be found. B. affinis became the first bee federally (and still only) listed as endangered in 2017. Not just bumblebees are in decline. Another study, conducted from 2005-2012 in the mid-Atlantic states of the U.S. found that visitation to crop flowers by wild bees declined 58% during the study period. With bumblebees experiencing a 56% decline, and non-bumblebee species declining by 61%. In an analysis of available information of all of North America's bee species, the Center for Biological Diversity found that of the more than 1400 species for which sufficient information existed, more than half have seen declines in population. They estimate that of these 1 in 4 may be at risk of extinction. Unfortunately, like for many invertebrate species, the majority of species have not been assessed, leaving a huge gap in knowledge about the health of bees and so many other essential invertebrates. Of course these declines are not restricted to just North America and declines of native wild bees have been recorded all over the world. 

© T. Thomas Rathe

Over the years many of you may have noticed less bees visiting your flowers. Maybe you haven't really paid attention. If you haven't, I don't blame you. Insects are one of those things we often take for granted. We sort of just assume they'll always be around. But if you've noticed a decline where you live or not, less bees are a concern for all of us. So what might be causing this decline? Well certainly the loss of habitat is the biggest factor involved in biodiversity loss among all species. There is no doubt that in many of the worlds landscapes, bee friendly habitat as taken a severe hit. In North America, most of its vast prairies were long ago converted to agricultural fields, but few would realize that its grasslands are still being converted to crops. According to the WWF, 2.6 million acres of North American grassland was lost to the plow between 2018 and 2019. In the United States 400 million acres are now covered in crops. Likewise, urban expansion continues to encroach on wild spaces. Urban areas in the U.S. grow about 15% per year, and now cover nearly 70 million acres of the U.S. Added to the loss of wildlands in general, cattle grazing on remaining wildlands can degrade grasslands and alter species abundance of bee critical plants. This combines with the introduction invasive plants that can alter landscapes, impacting bees ill adapted to their presence.

However, many bee declines seem to be out pacing habitat loss, and while much less diverse than wild landscapes, agricultural lands do provide habitat for bees. The largest concern is that these declines may be due to the use of a particular class of insecticide the neonicotinoids. Use of these pesticides have skyrocketed in recent decades going from almost zero in 1992 to nearly 8 million pounds per year by 2014. Neonicotinoids are now the most used class if insecticides, and many of them are highly toxic to bees. The most used of the class, imidacloprid, will kill 50% of honeybees exposed to just .0035 µg or 3.5 billionths of a gram. Wild bees, such as bumble bees, can be even more susceptible to its effects. Other than the real possibility of bees dying from exposure to these pesticides, there are many sub-lethal effects to exposure. One study found that neonicotinoid exposure reduced the queen production of the buff-tailed bumble bee (B. terrestris) by 80%. Mason bees are also affected, with research finding that the reproductive output of Osmia bicornis by 50%. In response to the impacts of these pesticides on bees the European Union banned the use of many neonicotinoids outside of greenhouses particularly clothianidin, imidacloprid and thiamethoxam, which are the most toxic to bees. Unfortunately, these are still widely used here in the United States with imidacloprid in particular being the most used insecticide in the U.S. 

An assessment of the buildup of pesticides on agricultural lands found "The toxicity loading of insecticides on agricultural land and surrounding areas has increased by approximately 50-fold over the last two decades producing both direct and indirect effects on associated ecosystems.", the vast majority of this toxic loading is coming from neonicotinoids.

While neonicotinoids are the pesticides of most concern regarding bees. The most used pesticide in the world, glyphosate, may also be harming bees. Found in the common weedkiller Roundup, and used extensively in agriculture worldwide, more than 1.8 billion pounds of glyphosate is used each year around the world. Multiple studies have found negative impacts on bees exposed to glyphosate including gut disruption and effects on larval development in honeybees, and disruption of the ability of bumble bees to thermoregulate their hives. The effect of glyphosate on bees has only recently been studied and its likely other detrimental effects will be found. It is clear that glyphosate is less toxic to bees than neonicotinoids, but its massive use is of huge concern.  

Steve Knight cc-by-2.0.  

Things you can do to help bees. 

There are lots of ways you can help pollinators. One of the easiest ways to do this is to have a flower garden. Whether something elaborate or just a simple window box, planting pollinator friendly plants can go a long way in increasing the available habitat for bees. In a sea of manicured lawns, your house can become a vital oasis for hungry bees. Bees need more than just flowers. Make sure your yard has places for them to live too. Different bees have different needs. Some are ground nesters that need an undisturbed patch of land to make their burrows. Some will seek out wood and hollow stems to lay their eggs. Consider building a bee hotel. Check out this handy link from Michigan State University:

 Building and Managing Bee Hotels for Wild Bees.

Certainly one of the ways is to cut your own pesticide use. Limit the amount of pesticides of all types you use around your home. Pull weeds instead of spraying them, or better yet replace turf grass with native plant species. Many communities in the West are paying people to do just that in an effort to save water. The result is a much more attractive yard that uses less water, fertilizers and pesticides and is cheaper and easier to maintain. No more mowing! The other major thing you can to to cut pesticide use is to buy organic. 

The debate rages on on whether organic foods are actually healthier than their conventional counterparts. According to government testing the vast majority of conventionally grown foods have pesticide residue levels below EPA guidelines. Whether these guidelines constitute a safe level of consumption is another debate entirely, but one aspect of going organic can't be argued. That's that organically produced foods and goods such as organic cotton and hemp products prevent a huge amount of pesticides from being used in their production. Buying organic is probably (and I believe likely) beneficial to your health, but most certainly better for the environment and for bees. 

Lastly, lobby your government at the local, state, and national level to reduce or eliminate the use of neonicotinoids. Many communities and some states have already restricted their use, but the EPA seems reluctant to curb widespread use nationwide. This will likely continue unless public pressure changes this.

References:

Colla, S. R., & Packer, L. (2008). Evidence for decline in eastern North American bumblebees (Hymenoptera: Apidae), with special focus on Bombus affinis Cresson. Biodiversity and Conservation, 17, 1379-1391.

Cameron, S. A., Lozier, J. D., Strange, J. P., Koch, J. B., Cordes, N., Solter, L. F., & Griswold, T. L. (2011). Patterns of widespread decline in North American bumble bees. Proceedings of the National Academy of Sciences, 108(2), 662-667.

Jacobson, M. M., Tucker, E. M., Mathiasson, M. E., & Rehan, S. M. (2018). Decline of bumble bees in northeastern North America, with special focus on Bombus terricola. Biological Conservation, 217, 437-445.

Aldercotte, A. H., Simpson, D. T., & Winfree, R. (2022). Crop visitation by wild bees declines over an 8‐year time series: A dramatic trend, or just dramatic between‐year variation?. Insect Conservation and Diversity, 15(5), 522-533.

https://www.biologicaldiversity.org/campaigns/native_pollinators/pdfs/Pollinators_in_Peril.pdf

https://files.worldwildlife.org/wwfcmsprod/files/Publication/file/5yrd3g00ig_PlowprintReport_2021_Final_HiRes_b.pdf?_ga=2.7065650.1451756164.1677188443-1178640786.1677188442

Li, Y., Miao, R., & Khanna, M. (2020). Neonicotinoids and decline in bird biodiversity in the United States. Nature Sustainability, 3(12), 1027-1035.

Woodcock, B. A., Isaac, N. J., Bullock, J. M., Roy, D. B., Garthwaite, D. G., Crowe, A., & Pywell, R. F. (2016). Impacts of neonicotinoid use on long-term population changes in wild bees in England. Nature Communications, 7(1), 12459.

DiBartolomeis, M., Kegley, S., Mineau, P., Radford, R., & Klein, K. (2019). An assessment of acute insecticide toxicity loading (AITL) of chemical pesticides used on agricultural land in the United States. PloS one, 14(8), e0220029.

Motta, E. V., Raymann, K., & Moran, N. A. (2018). Glyphosate perturbs the gut microbiota of honey bees. Proceedings of the National Academy of Sciences, 115(41), 10305-10310.

Vázquez, D. E., Ilina, N., Pagano, E. A., Zavala, J. A., & Farina, W. M. (2018). Glyphosate affects the larval development of honey bees depending on the susceptibility of colonies. PloS one, 13(10), e0205074.

Crall, J. (2022). Glyphosate impairs bee thermoregulation. Science, 376(6597), 1051-1052.