Is there a pollination crisis?

This is a delicate topic for me, as I study pollination services in agriculture and the answer to this question can directly impact the funding and interest in my research.  It’s also a very complex issue; the answer varies globally and even within countries.  This is a very US centric post because that is where I have researched bees and pollination services, but feel free to chime in below with a comment about pollination services in other countries!

I’m going to divide this issue into two chunks because there are two major groups of insects that contribute to crop pollination: domesticated bees (mainly the honeybee), and wild bees that already exist in the environment and provide “free” pollination services to agricultural crops.

Domesticated Bees

Humans have had a long association with the honeybees; there is evidence that they were domesticated over 4,000 years ago in ancient Egypt and they have followed humans ever since (Buchmann 2006).  The original purpose of their domestication was honey production, but modern agriculture relies more on the pollination services provided by the bees.  In the US alone, the pollination services of honeybees are valued at over 15 billion dollars a year (Morse and Calderone 2000) (19.3–40.3 billion US$ when adjusted for inflation in 2012).

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From “Letters from the Hive: An Intimate History of Bees, Honey, and Humankind”, Buchmann 2006

Widespread attention was brought to the honeybees after Colony Collapse Disorder was first reported in 2006 (vanEngelsdorp et al. 2006).  The case of the “disappearing bees” was alarming because we didn’t know what caused it and because we couldn’t study the dead bees…they simply never returned to the hive.

The result of this original scare was twofold.  First, a huge amount of research was funded to find the cause of Colony Collapse Disorder and to combat it (that’s a whole other post).  Second, we realized just how fragile depending on a single species for all of our pollination services could be.

Honeybee on Ohio Spiderwort

Honeybee on Ohio Spiderwort

Though bee keepers are still experiencing large losses every winter, there is convincing evidence to show that there are more honeybees than ever before (Aizen et al. 2008).  How can this be called a pollination crisis?  Actually, though the number of honeybees has increased, our dependence on them has outpaced their growth.  The number of pollinator dependent crops is increasing at a rapid rate (Aizen and Harder 2009).

Wild and Native Bees

This issue gets more complex.  Because of the threats to the honeybee, researchers started looking for alternative pollinators.  After all, there are more than 20,000 bee species worldwide!  We’ve learned so much about native bees just in the past few years, and the research community is buzzing*, so to speak, about their potential to provide all of the pollination services that crops require.

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I’m a pollinator!

Are those native and wild bees in decline?  We don’t really know (Ghazoul 2005).  There is some evidence to suggest that some groups of wild bees are declining (Bartomeus et al. 2013), but we really don’t know enough about their past abundance and distribution to say for sure.  We only started really studying them when the honeybees began to suffer!  As a result, we don’t have a baseline to judge.

We’re searching for species that can be domesticated (such as the mason bees (esp. Osmia spp.) and bumblebees (especially Bombus impatiens)) and ways to improve nesting habitat for mining bees.  Farmers have even begun to invest in floral provisioning strips to boost native bee abundance within their fields.

And we know that native and wild bees can provide all of the pollination services that agricultural crops require…IF they have enough habitat (Garibaldi et al 2013).

So that’s all great, right?  It sounds like we have resources we can rely on, spreading out our dependence to many species, and strategies for encouraging them are well on their way.

Threats to Pollination Services

But the elephant in the room is big agriculture.  The wild bees can’t survive in monocultures of almonds spanning hundreds of hectares in California (Klein et al. 2007).  And in the meantime the bees (and all other insects at the same time) are being pounded by pesticides.  And not just the insecticides made to kill insects, but fungicides and herbicides.  They are not only toxic themselves to the bees, but the herbicides also have a huge impact on non-crop floral resources on field edges.

Recent work by Chris Mullin shows that there are more than 98 different pesticides in honeybee pollen (Mullin et al. 2010).  And a recent paper that came out this year shows that most of the pollen in honeybee hives is from weedy field edges (Pettis et al. 2013).  Those edges are strongly impacted by pesticide use.

So what do you think?  Is there a pollination crisis?  Is it imminent?  We can’t say for sure, but there are plenty of reasons to invest in pollination services.  After all, we owe the diversity and colour of our diet to the pollination services provided by insects.  And that diversity and colour is directly linked to our health and longevity.

As I once heard May Berenbaum say, “If we lost bees, we wouldn’t starve**, but we’d all get scurvy pretty fast!”

*Pun intended
** Staples like wheat, rice, and corn do not require insect pollination.

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12 thoughts on “Is there a pollination crisis?

  1. Great post, I’ll include this in my local beekeeping association monthly e-newsletter.

    If legislation was passed requiring the almond growers to plant a certain amount of wild flowers amongst their trees that would probably help a lot. To me it would make economic sense if the growers did this, because then wild bees could survive all year round and they wouldn’t have to keep relying on beekeepers bringing bees in from distant parts of the country.

    • There is a lot of economic incentive to develop strategies for promoting pollination services from wild bees. Unfortunately, a lot of the growers out west are very set in their ways and big intensive agriculture is slow to change. The other challenge is that we are not that confident about what to plant or where to give the strongest boost to the bees.

  2. An interesting an concise post on a subject that is getting a lot of attention. I had never heard about the increase in crops requiring pollination. I think the problems are very specific to the geographic location and the crop so it is not a one solution fits all scenario.
    As you know I love the wild bees that visit my garden and I am systematically increasing pollen and nectar producing plants for them. If I were to keep a hive of honey bees would I reduce the number of native bees visiting my garden? I’d really like to have your opinion.

    • That is also a complicated issue…maybe I should dedicate a post to it as well! We’re not really sure about the impact that honeybees have on native bees. There have been mixed results in observational studies…some suggest that the honeybee has a competitive negative effect on native and wild bees, but others do not support that claim.

      As you suggest, it may depend on the geographic location for this as well.

      However, my intuition is that keeping honeybees would not negatively affect your wild bees. I guarantee that there are already honeybees somewhere in your area, and hopefully the abundance of flowers in your garden would prevent a competitive effect. I will try to read more about this issue to get you a better answer.

  3. The hysteria and hype over the pollination crisis seem to have subsided in the year since you wrote this piece. The sad thing is that people get shocked when the media makes a big deal of something and promptly lose interest and move on to the next acute crisis, be it Ebola or whatever. The main problem, loss of native pollinators, persists but hardly anybody confronts it adequately.

    The real pollination crisis must have started gradually a hundred years ago or longer with the growth of agriculture and our increased dependence on a single pollinator species. The Division of Bee Culture of the USDA published “The Dependence of Agriculture on the Beekeeping Industry—a Review” in 1942 (http://archive.org/stream/deperi00unit/deperi00unit_djvu.txt). They said among other things: “Wild bees are no longer adequate or dependable. . . In many places the depletion of wild pollinators is so acute that honeybees have to be brought in especially for pollination.” They presented some evidence of the loss of wild bees. See my blog piece “Bring Back the Native Pollinators” (http://nativeplantwildlifegarden.com/bring-back-the-native-pollinators-we-need-them-more-than-ever). It is obvious that our dependence on honey bees postponed and also contributed to the real pollination crisis.

    BTW, in addition to Bartomeus work on bee species decline, it is worth mentioning that of Burkle on loss of wild bee species since the 1800s in Carlinville, Illinois. (http://www.scientificamerican.com/article/where-the-wild-bees-are/)

  4. Pingback: Pollinators make an awesome study system | standingoutinmyfield

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