Creating Landscapes to "Save the Bees" and Save Ourselves
By. Katherine Burns
Though she looks like her bumblebee cousins, you can tell that she is a carpenter bee from the lack of hair on her abdomen - bumblebees are much fluffier. These bees make their homes by tunneling into wood, hence their name.
We live in an increasingly fragmented landscape. As humans, we prefer our world to be paved, mowed, and manicured. Every flower that blooms must do so with our permission. We are one of the most effective ecosystem engineers that this planet has ever seen, surpassing even the beaver, whose dams have the ability to modify entire river systems. In many ways, our engineering prowess has earned us many benefits, including our expansive agricultural systems, which currently grant us food security. However, these same modifications that grant us our modern conveniences and comforts are also the ones that may destroy the system entirely.
In order to feed the 7.5 billion people who call this planet home, about a third of Earth’s land has been devoted to agricultural activities, including the growing of food crops. About 75% of crop species need a little help to produce the seeds and fruits that we consume, usually in the form of a wildlife ménage à trois. These third-party partners, called pollinators, carry pollen from one flower to another so that the crop plant can reproduce. While the service of pollination is carried out by many species of animal, including bats and birds, the majority of pollinators are insects, such as bees, flies, moths, and beetles. These insects carry out pollination unknowingly, as they are usually visiting flowers in order to gather pollen and nectar to feed themselves or their offspring, but inevitably get pollen stuck to their bodies, which they then carry to other flowers. Unknowingly or not, however, these insects are essential for producing all of our favorite foods, like strawberries, blueberries, coffee, and chocolate.
Since the 1960s, the amount of land devoted to pollinator-dependent crops has increased more than 70% in the developed world, meaning that the need for healthy, active insect pollinator populations has also increased. Unfortunately, these expansions have occurred at the expense of natural areas, such as forests and prairies, where many insect pollinators live and raise their offspring. There is mounting evidence to show that insect pollinator populations are currently in decline and further evidence showing that agricultural practices, such as habitat fragmentation and pesticide use, pose threats to insect pollinator survival. In other words, the same system that requires these insects is also contributing to their decline.
While pollinators do feed on the pollen and nectar of many flowering food crops, the majority of these crops have a blooming period of only two weeks, which is shorter than the average pollinating insect lifespan. Most of these crop fields are aggressively managed through both mowing and chemical applications, which can reduce the number of wildflowers growing in the natural landscape and thus diminish pollinator food supply. If insects don’t have access to enough food, they may starve before they have a chance to reproduce or, in the case of bees, may not be able to gather enough food to feed their babies. Excessive mowing can also reduce the amount of long grasses and shrubs growing along field edges, which would otherwise serve as nesting habitat for some bee species. Additionally, insecticide and herbicide applications may kill or severely damage insects who attempt to visit the flowers of the crop. Therefore, crop landscapes are not generally hospitable environments for insect pollinators, despite the fact that pollinators are needed in order to produce high fruit yields. Pollinator decline poses the risk of losing up to $577 billion in annual global crop outputs and, already, we have seen nearly a 25% loss in cropland productivity, despite the increase in land area devoted to crops.
Hoverflies have protective coloration to mimic the patterns of either wasps or bees, depending on the species, to make themselves seem more formidable. However, this fly’s single pair of wings gives him away (wasps and bees have two pairs of wings).
One common solution to the double-edged sword of crop production is the use of managed honeybees, which do not depend on the availability of natural resources (i.e. food and nesting habitat) to survive. The European Honeybee (Apis mellifera) is a little golden insect that produces honey, lives in a hexagonal hive, and is the poster child of “Save the Bees” campaigns. When most people think about bees or pollinators, they usually think of this bee first. Honeybees have been domesticated for hundreds of years and were introduced to North America in the early 1600’s, where they are currently used widely for the production of honey and for crop pollination services. Honeybees are a favorable choice for supplementing crop pollination since their hives can be shipped all over the country to follow the blooming times of different crops, as opposed to wild pollinators that do not possess this level of human-aided mobility. However, while this bee species has long been regarded as the most important pollinator for crops, in reality, the honeybee is just the most convenient.
Different types of plants depend on different types of pollinators to pollinate them. Long, tubular flowers require pollinators with a very long tongue and tiny flowers need a pollinator with a very small body size. There are even some flowers that need to be buzzed at a specific frequency that only some bees can produce in order to release their pollen. Therefore, in order to effectively pollinate a huge diversity of crops, all differing in shape and size, a large diversity of pollinators is needed. As a result, honeybees are not always the most efficient pollinator of the flowers they visit and it has been shown that wild pollinators, including bumblebees, solitary bees, hoverflies, and moths, contribute to about 50% of global crop pollination. Additionally, while there has been a great deal of media coverage on honeybee decline, this is an issue that affects the livelihoods of beekeepers more than honeybee populations overall. Buying a honeybee hive to “Save the Bees” is the equivalent of buying chickens to “Save the Birds;” as a livestock species, it is very unlikely that these bees will go extinct. Wild pollinators, on the other hand, do not have keepers looking after them to provide them with housing and supplement their food supplies. Therefore, it is imperative that ample floral and nesting resources are available in the environment to support these species.
Bumblebees are capable of “buzz pollination,” in which the bee uses its flight muscles to vibrate a flower’s anthers to release the pollen. Some flowering plants require buzz pollination to reproduce, such as tomatoes and blueberries.
Protecting and promoting native, wild pollinator diversity, is necessary for both the production of crops, as well as the pollination of over 85% of wild plant species. With the expansion of agricultural land and urban areas, the landscapes that surround us are becoming more fragmented and devoid of wildlife. Therefore, it is more important than ever to implement conservation based actions to preserve wild insect pollinators, as well as other species. Luckily, organizations such as the Xerces Society for Invertebrate Conservation, are already working to implement conservation initiatives for the protection of pollinators. This includes actively engaging with farmers to implement more pollinator-friendly practices, while also maintaining agricultural productivity, in order to create a more balanced system that benefits both pollinators and farmers.
We have been trained to crave order and tidiness, but this system does not benefit the creatures upon whom we depend. Embracing a messier, less managed landscape is the first step to protecting wildlife, including insect pollinators, and the services that they provide. There are plenty of ways to do this in your everyday life, many of which require doing less. One of the easiest ways to provide habitat for pollinators is to reduce lawn mowing and allow wildflowers (such as dandelions and clovers) and long grasses to flourish, providing food and habitat for insects. Another easy way to embrace a “messier” landscape is to leave Autumn leaves on the ground, which will provide bees, moths, and butterflies with a safe place to either hibernate or cocoon over the winter. For those with a green thumb, planting native nectar and pollen-rich plants at your home, school, church, or community center can also provide oases for hungry insect pollinators - even a window box can make a difference.
Male solitary bees do not live in nests and spend the majority of their lives actively searching for females to mate with, so you can often find them slowly warming up on flowers or leaves on chilly mornings. This bee is using one of my pollination experiments as his morning perch.
As innovative ecosystem engineers, we have the opportunity to use our talents to build landscapes that benefit humans, while also allowing other species to survive and thrive. We can find ways to feed the growing human population without stealing food from the mouths of other species. If we want to continue benefiting from the services of pollinators, we need to make a little more room for them.
If you are interested in becoming a pollinator protector, the Xerces Society is an excellent resource for regional native plant lists, as well as lots of other evidence-based materials to protect pollinators: www.xerces.org.
Katherine Burns is a PhD researcher and science communicator based at the School of Agriculture & Food Science at University College Dublin. She describes herself as a "joyful ecologist” with a passion for getting people excited about this amazing planet that we live on, especially all of the “little things that run the world.” Her main research interests are the public perceptions of pollinators, crop pollination, and interactions between managed and wild pollinators.
Katherine has participated in several science communication events, including the international competition, FameLab, and the Irish science comedy event, Bright Club. To watch her performances, in which she highlights the importance of bees (and the difference between managed and wild bees) check out the videos below:
Aizen, M. A., Garibaldi, L. A., Cunningham, S. A., & Klein, A. M. (2008). Long-term global trends in crop yield and production reveal no current pollination shortage but increasing pollinator dependency. Current Biology, 18(20), 1572-1575. doi:10.1016/j.cub.2008.08.066
Garibaldi, L. A., Steffan-Dewenter, I., Winfree, R., Aizen, M. A., Bommarco, R., Cunningham, S. A., . . . Klein, A. M. (2013). Wild pollinators enhance fruit set of crops regardless of honey bee abundance. Science, 339(6127), 1608-1611. doi:10.1126/science.1230200
Herbertsson, L., Lindstrom, S. A. M., Rundlof, M., Bornmarco, R., & Smith, H. G. (2016). Competition between managed honeybees and wild bumblebees depends on landscape context. Basic and Applied Ecology, 17(7), 609-616. doi:10.1016/j.baae.2016.05.001
IPBES. (2019). Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science- Policy Platform on Biodiversity and Ecosystem Services. Retrieved from https://ipbes.net/global-assessment
Klein, A. M., Vaissiere, B. E., Cane, J. H., Steffan-Dewenter, I., Cunningham, S. A., Kremen, C., & Tscharntke, T. (2007). Importance of pollinators in changing landscapes for world crops. Proceedings of the Royal Society B-Biological Sciences, 274(1608), 303-313.
Ollerton, J., Winfree, R., & Tarrant, S. (2011). How many flowering plants are pollinated by animals? Oikos, 120(3), 321-326. doi:10.1111/j.1600-0706.2010.18644.x
Potts, S. G., Biesmeijer, J. C., Kremen, C., Neumann, P., Schweiger, O., & Kunin, W. E. (2010). Global pollinator declines: trends, impacts and drivers. Trends in Ecology & Evolution, 25(6), 345-353. doi:10.1016/j.tree.2010.01.007
Rader, R., Bartomeus, I., Garibaldi, L. A., Garratt, M. P. D., Howlett, B. G., Winfree, R., . . . Woyciechowski, M. (2016). Non-bee insects are important contributors to global crop pollination. Proceedings of the National Academy of Sciences of the United States of America, 113(1), 146-151. doi:10.1073/pnas.1517092112