The decline of native pollinators as a result of agriculture and beekeeping practices

Many problems facing bees of all sorts can be directly linked to agriculture as well as beekeeping practices themselves. Most problematic, is the use of neonicotinoid pesticides on bee pollinated plants, but a number of factors compound to create health problems that can spread to wild bees.

For: Prof. Juha Helenius
Professor of Agroecology
University of Helsinki

Originally for Kari Koivulehto – Mehiläistalous (MAAT224) – Spring 2013


The domesticated honeybee Apis mellifera L. is popularly recognised for its significant economic contributions to food production, especially their pollination services on which a third of all crops depend (Gallai 2009). There has been a great deal of concern in recent years about their ability to meet the demand for animal pollinated produce which has increased by 300% in the last half-century, whereas the number of commercial bee hives has increased by only about 45% (Aizen 2009). Though economic factors surely play a role, they have also faced significant health issues, in particular Colony Collapse Disorder (CCD), a phenomenon observed since 2006 in which hives succumb to purportedly unknown factors. In actuality, their decline can rather convincingly be attributed to a number of conditions that compound to reduce the vitality of individual colonies to a varying degree. Despite this, the number of hives in production is about as high as ever.

Native bees species on the other hand are affected by the same environmental challenges and additionally have to compete with farmed bees for pollen and nectar. In most regions of the planet the domestic honeybee could be considered an invasive species, one that wouldn’t survive without supplemental food in the form of sugar water through the winter. They are also generalists who often rob nectar and pollen from plants without actually triggering the mechanisms that specialist pollinators are adapted for. Considering that there are thousands of species performing animal pollination, it seems very anthropocentric to focus only on our one pet species at the expense of all other native bees and the ecosystems for which they are integral.

“Plight of the Bumblebee”

Some factors affecting the health of bees might be fairly inconspicuous, like the potential for climate change to affect seasonal patterns. This could disrupt the sensitive timing of flower-pollinator relationships, especially in the early spring when resources are scarce. Air pollution has also been shown to hamper the bees’ ability to discover food sources (McFrederick 2008).

Many problems facing bees of all sorts can however be directly linked to agricultural practices themselves. Land conversion contributes to the fragmentation and loss of natural habitat, reducing the diversity of forage. Even more problematic, is the use of neonicotinoid pesticides. Food crops like canola and fruit trees might be sprayed even during pollination activity. Even in small quantities, this neurotoxin reduces the bees’ ability to return to the hive, especially when in unfamiliar territory (van der Sluijs et al. 2013).

In the case of farmed bees, CCD is also correlated with increased viral activity (Chejanovsky 2014, Hou 2014). The long-distance transportation of hives for use in pollination could promote the exchange of parasites and diseases. In the U.S.A. for example, hives are shipped thousands of miles from New England to California to pollinate almonds, during which time they’ll be in contact with bees from all over the country. There is evidence that many of these pathogens can transfer between bee species. Outbreaks in captive honeybee populations could conceivably spread to wild populations, for example Nosema sp. Zander has been shown to transfer from honeybees to bumblebees Bombus sp. Latreille through common host flowers (Graystock 2015).

The Forgotten Pollinators

The Forgotten Pollinators

In his book, “The Forgotten Pollinators”, Stephen Buchmann (1996) offers great insight into the huge diversity of animal pollinators and the essential work that they perform. Bees in all of their varieties are still only one group among others big and small: butterflies, moths, bats, birds, flies and even tiny insects like thrips Thysanoptera Haliday. These all suffer the same hardships as a result of widespread industrialised agriculture and land fragmentation, even more so when they are highly specialised. Leaf-cutter bees suffer especially from pesticides as their residues remain on leaf-cuttings used to build their brood cells. Monarch butterflies Danaus plexippus L. migrate huge distances from Mexico to Canada every year and rely on a corridor of nectar sources and larval host plants that is increasingly discontinuous. Honeybees, as an invasive species, can disrupt highly co-evolved symbiotic relationships. As if that human meddling isn’t enough, Africanized hybrid bees, originally introduced to Brazil in order to increase honey production have spread all the way to the southern United States.


There is a certain sense of rural-romanticism that beekeeping appeals to, but the task of keeping bees healthy is not to be taken lightly. Some people seem to assume that establishing a beehive is generally good for nature. I myself have observed bumblebees at work pollinating apple trees at my cottage and decided that it would be unfair to disrupt the balance by farming my own bees, though the honey would certainly be desirable!

When one does engage in the practice, a thorough knowledge of sanitation and care practices would help to mitigate any potential risks. There might in any case be good reason to recommend insect hotels over production hives, in order to accommodate a more diverse range of inhabitants. It may be that there is enough net nectar for all, but whether it is available when and where it is needed and without the risk of contamination is another question. Both agriculture and beekeeping practices could definitely become more sustainable by designing them with consideration for the ecology of all the hard-working pollinators.


Aizen, M. A. 2009. The Global Stock of Domesticated Honey Bees Is Growing Slower Than Agricultural Demand for Pollination. CURRENT BIOLOGY 19: 915-918.

Buchmann, S. L. 1996. The Forgotten Pollinators. Washington, DC: Island Press.

Chejanovsky, N. 2014. Characterization of viral siRNA populations in honey bee colony collapse disorder. Virology 454: 176-183.

Gallai, N. 2009. Economic valuation of the vulnerability of world agriculture confronted with pollinator decline. Ecological Economics 68: 810-821.

Graystock P. 2015. Parasites in bloom: Flowers aid dispersal and transmission of pollinator parasites within and between bee species. Proceedings of the Royal Society B: Biological Sciences 282.

Hou, C. 2014. Dynamics of the Presence of Israeli Acute Paralysis Virus in Honey Bee Colonies with Colony Collapse Disorder. VIRUSES-BASEL 6: 2012-2027.

McFrederick Q. 2008. Air pollution modifies floral scent trails. Atmospheric Environment 42: 2336-2348.

van der Sluijs, J. P., Simon-Delso, N., Goulson, D., Maxim, L., Bonmatin, J. & Belzunces, L. P. 2013. Neonicotinoids, bee disorders and the sustainability of pollinator services. Current Opinion in Environmental Sustainability 5: 293-305.