Decline of pollinators threatens our agricultural system

Bees pollinate more than three quarters of our most commonly-cultivated crops. [Andy Murray/Flickr]

Pollinating insects are facing threats on an unprecedented scale, but our need for them has never been greater. Our partner Journal de l’Environnement reports.

The newly-established Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), nicknamed the “IPCC of biodiversity”, has begun its work by addressing the issue of pollinators.

The knowledge that pollinators are in danger is nothing new, but the IPBES hopes that its first set of policy recommendations will help save global bee populations, whose decline could have catastrophic repercussions for mankind.

From the very beginning of its Summary for Policy-Makers, published on Friday (26 February) following the organisation’s fourth plenary session in Kuala Lumpur, the IPBES highlighted the importance of pollinators to agriculture: more than three quarters of the most-cultivated crop types depend on pollination by insects. These crops cover around one third of all farmland.

An estimated $235 to $577 billion per year of agricultural production relies on pollination. As a result of the growth in agricultural production, our dependence on pollinators has grown by more than 300% over the last five decades.

Global decline

With a booming global population, this is no time for our agricultural practices to push the pollinators into decline. But that is exactly what is happening. In Europe and North America, many wild species of bees and butterflies are coming under increasing pressure. The data for other continents is less reliable, but a number of local studies have shown declining populations to be a world-wide phenomenon.

For the IPBES, there are many reasons behind this phenomenon, including habitat deterioration, pesticides (primarily neonicotinoids), pathogens like varroa (a mite that infects honey bees), invasive species like the Asian hornet, or even climate change.

The IPBES also mentioned some less well-understood causes, for example the use of herbicides. By reducing the diversity of flowers and plants in a given area, these chemicals cut down on the amount of food available to the pollinators.

With the EU currently reconsidering its partial moratorium on three types of neonicotinoids, the association Pollinis has planned to submit its ‘StopNeonics!’ petition to the European Parliament in early March. Launched in May 2012 and signed by more than one million people, this petition calls for a definitive ban on all pesticides of this kind.

Pesticides pose risk to bees, EU watchdog says

Widely-used pesticides made by Bayer CropScience and Syngenta pose a risk to bees, the European Union’s food safety watchdog said yesterday (26 August), reinforcing previous research that led to EU restrictions.

The impact of GMOs

The effects of other factors on pollinator populations remain surprisingly poorly understood. According to the IPBES, it is likely that herbicide-resistant genetically modified plants could also negatively affect populations by encouraging the use of these chemical products.

But the issue is far from clear: some experts believe insect-resistant GMOs could be beneficial for pollinators, but there is not currently enough data to draw reliable conclusions on the subject.

Even without chemical products, mankind’s activities can harm pollinating insects. In its summary, the IPBES cited the case of North and South America, where bee populations have suffered as a result of parasites introduced along with the European species used by commercial bee-keepers. A study published in early February showed that the deformed wing virus (DWV) became a global problem due to the trade in European honey bees.

So, how can the decline be halted? According to the IPBES, by making some general changes to agricultural practices: supporting organic production systems, diversifying crops, cutting the use of pesticides and preventing pesticide drift, and planting fields with borders of flowering plants.

Are bees getting hooked on pesticides?

Like nicotine for humans, certain pesticides seem to hold an addictive attraction for bees, which seek out tainted food even if it may be bad for them, research showed Wednesday (22 April).

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