Categories: AgricultureAgriculture Myth Busting

Bees: How Many Colonies Does Agriculture Hurt?

Agriculture Myth Busting

Food is nothing without pollinators and, in Canada, bees are of particular importance. A third of all Canadian food is produced with the help of bees and some commodities (i.e. produce, nuts, seeds) are more reliant than others. Companies have thrived providing farmers with firsthand experience of pollinator benefits and subsequent apiculture training through hive rentals, ultimately building farm capacity for full-time bee colony involvement. Some businesses, in an effort to maintain honey quality and bee health, will rent hives for a limited list of crops and only for the (typical month-long) growing season before retaking possession – a common practice in some sectors known as migratory beekeeping. The California almond industry, for example, employs up to 80 billion bees for the two-week bloom period, emphasizing the incomparable worth of bees, which is valued at twenty times that of the honey produced by some species.In 2021, Canadian canola seed production generated approximately twelve billion dollars for the industry, of which, seven billion dollars could be directly attributed to the pollination work of bees. This figure does stand on the higher end of value estimates, but both the contribution and management costs of hives is dictated by the type of crops included in estimates. Independent of their value, bee populations have been variable across the last two decades, bringing up questions about the role of agriculture in exacerbating stressors and directly contributing to large drops in population. Whether or not agriculture is responsible for bee deaths, it is important to understand where these accusations are coming from and how much validity they hold.

While, historically, research and media spaces focused on major bee population declines in 2012-2016, the number of colonies in Canada has been increasing since, with 2021 cited as a record-high bee year for Canadians. Now, this latter statistic does not circumnavigate bee health and colony survivability concerns as a result of agricultural practices, but it is included so I can preface this blog’s discussion as follows: bees matter to farmers. What an obvious statement, but it is said because, regardless of what is responsible for bee deaths, farmers are only ever advantaged by pollinators in the field. The partnership between honeybees and Canadian canola fields is specifically referenced as economically advantageous (especially in Saskatchewan), and it costs farmers much less in recovery if the majority of their colonies stay alive. This is not said to bias the discussion, it is merely a punctuation that death is a consequence, not a malicious goal.

The Neonicotinoid Obsession

The conversation moving toward neonicotinoids seemed inevitable. The chemical group represents approximately a quarter of insecticides currently commercially available and is designed to selectively bind to and interrupt neuro-receptors in targeted pests. Neonicotinoids are frequently cited in media reports as the cause of bee mortality, except making that claim is difficult to back up. Neonicotinoids are not completely blameless, however, their inclusion in the discussion is attributable to their supposed full responsibility in past and present apiculturist mentions of the risk of “pesticides” to bee health (Table 1), despite 67% of pesticides used in Canada possessing a negligible risk to bees. Bee-pesticide incidents overall affect less than two percent of Canadian colonies although, notably, neonicotinoids affect more colonies than non-neonicotinoids. Overwhelming concern has led to increased guidelines for neonicotinoid use, including decreasing the number of applications allowed per season, decreasing the rates of applications, changing the list of allowable crops, and increasing buffer zones between treated and untreated rows.

Table 1. Summary of Canadian bee-pesticide incidents reported from 2007-2012 (Source)

When recollecting the onslaught of bee incidents a decade ago (partially shown in Table 1), the majority of deaths linked to the use of neonicotinoids occurred in Ontario and Quebec and were mainly attributable to weather complications rather than if neonicotinoids were present. Temperature (and season) specifically can influence the effects of neonicotinoids, with winter bees being much more metabolically sensitive to chemicals than spring/summer colonies. The differences in crop commodities between western and eastern provinces (i.e. canola vs. corn and soy) also partially contribute to neonicotinoid-related loss, but overall, it is not good enough to use trends in central-Canadian bees to make conclusions about prairie colonies, and vice versa. For instance, 95% of Canadian canola is seed-treated with neonicotinoids and yet, some recent reports no longer mention beekeepers’ use of pesticides, let alone neonicotinoids, as a top threat to prairie populations.Although there may not be much evidence linking declining bee populations to the use of neonicotinoids, the effects of neonicotinoid poisoning in bees can be very real. Exposure to chemicals designed to disrupt neuroreceptors can slow the rate at which bees learn foraging behaviours, making their ability to feed themselves and their queen incredibly difficult. The fear, beyond the impacts on bees, is that humans who interact with neonicotinoid-treated fields and pollinating songbirds who may be attracted to treated seeds, are at risk of unintended neurological consequences, although those effects are largely unexplored. It is important to note that the toxicity of agrochemicals is heavily dependent on exposure to those chemicals and, in many, many cases, field realities are not captured in lab simulations. To clarify, in order for researchers to observe negative effects on bee health as a result of neonicotinoids, colonies needed to be chronically exposed to chemical rates much higher than is real in agriculture. Data out of Mexico that was able to conclude a serious risk of neonicotinoids to bee health did so when nearly 88% of their neonicotinoid samples returned above sub-lethal doses; an increase in Canadian chemical-caused bee mortality was only observed when neonicotinoids were already interacting with fungicides and exposed to colonies at a concentrated rate 84 times that of environmentally realistic. Therefore, in the absence of field-realistic research, alternative causes of hive death beyond agrochemicals must also be assessed for their impacts.

Hive Stressors Shortlist

Prairie bees in their hive (Source)

Unfortunately, the 21^st-century trend of agricultural intensification has contributed to the variability of bee health, as there is a plethora of possible reasons that bees could be impacted beyond chemicals. Fundamental economic evolution to agriculture like decreased number of farms but increased farm size or the change to the Canadian honey market are large proponents of changing bee populations. Similarly, the more intense an operation, the more likely there exists a monoculture or a very limited rotation; by limiting the types of plants bees have access to, the abundance of bees is similarly limited as bees tend to move to fields with a greater foodstuffs diversity.A lack of suitable resources threatens the survivability of bees, especially through the winter. Of keepers who lost at least a quarter of their hives in 2020, starvation was the number one cause of bee mortality in Saskatchewan, Manitoba, and Prince Edward Island, although starvation has since become less of an immediate concern for beekeepers. Particular commodities that require migratory bees for pollination are frequently chastised for the stretches of famine bees experience during transport and it unfortunately appears to be an industry standard. Atlantic Canada and the blueberry market is similarly familiar with the acceptance of famine, where approximately 30% of bees die annually as a result of starvation and the lack of variety – 8% higher than the industry acceptable amount of colony loss. This reality of agriculture, coupled with how bees are expected to fit in a given operation and the state of apiculture reporting that leaves death responsibility largely uncertain, contribute to honey (or migratory beekeeping, in general) being an adversary for veganism and animal activists. Those bees that do survive winter are frequently ill-equipped to thrive in the spring, leaving room for disease and pests to affect the hive.Mites are another growing concern for apiculturists which reduce Canadian bee populations every year by about 50%; increasing global temperatures meant 2022 had the worst mite-related colony loss since the turn of the century. Diseases are frequently a concern of beekeepers – one recognized as requiring help from the government to address in both Ontario and the Maritimes – as declining health and strength can render the colony susceptible to other diseases and/or additional stressors. However, this is also a case for neonicotinoid use, in which their absence has been linked, in specific instances, to slightly higher cases of mites.Canada’s high correlation between bee deaths and contaminated agricultural dust is partially mitigated by 2014 legislation requiring dust-reducing agents on operations, which saw a subsequent 70% reduction in dust-associated deaths in the following years. However, the growing threat of climate change may exacerbate dryness and the production of planter dust. This includes seeing changes to seeding timing, so much so that additional efforts are required to prevent expected decimation. This is a concern shared by producers, as the government in 2022 improved AgriRecovery payments to prairie and Ontario beekeepers to compensate, among other reasons, for a particularly dry year. Without efforts to curb the impacts of climate change on bee health, the natural loss of upwards of 48% of colonies due to environmental stressors is likely to continue.

Concluding Remarks

Figure 1. Benefits of seed-treating with neonicotinoids instead of conventional spray (Source)

Despite recognition of alternative influences to bee health and improvements to agrochemical best practices, banning neonicotinoids is still touted as the best option for improving populations. While the incidental loss is certainly unnerving, the suggestion fails to acknowledge the consequences of widespread neonicotinoid substitution, or the indirect benefits of seed-treating (as opposed to spraying) for pests (Figure 1). The European Union, which has banned the use of neonicotinoids, has seen yields decline as a result. It is also reported that moving away from neonicotinoids will cause farmers to turn toward broader chemicals with potentially fewer application guidelines to ensure safety, and less targeted applications that may give rise to pests. However, much like the incidence of pesticide-related bee loss, strategies to maintain and/or improve health are farm specific.The hyper focus on correlating neonicotinoids to bee health has unfortunately limited the availability of information. Improving knowledge transfer and communication, especially when acknowledging the regionalism of bee incidents, can allow beekeepers to work together to determine and address current threats to colonies. Without detailed reporting on all aspects of agriculture and the subsequent impacts to bee populations, it is difficult to definitively conclude whether agriculture is deserving of its pollinator reputation. More disappointingly, though, the lack of detail in apicultural reports prevents farmers from properly responding to bee stressors and limits how effectively they can support themselves and others in the industry.

Interested in busting more myths?

Claire Williams

Claire is a research assistant at the University of Saskatchewan. In 2019, she completed her degree in animal science and her degree in agricultural and resource economics in 2020 from the U of S. She subsequently completed her Master's in Agriculture Economics under the supervision of Dr. Tristan Skolrud in 2023. As of the summer of 2022, Claire has joined Dr. Smyth's research team and is collaborating on SAIFood posts.

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