A GLOBAL MAP OF INSECTICIDE USE, USING HONEY
Firstly, what are neonicotinoids?
They are a relatively new, water soluble insecticide chemically similar to nicotine.
Why are they popular?
It can be applied directly to soil, reducing the risk of drift away from the target area. Also, it has shown significantly lower toxicity rates for birds and small insect eating mammals.
So what’s the problem?
Initially neonicotinoids weres thought to be safe for pollinators, but new evidence shows it is responsible for Colony Collapse Disorder (CCD) in bees. Bees exposed to the insecticide have trouble returning to their hives. Exposed hives have a lower overwintering rate, and queens fed neonicotinoids have a lower reproductive rate. In the last 10 years, more than 40% of bee hives have been impacted by CCD, and we rely on bees to pollinate a significant portion of our food crops, especially fruit.
How widespread is the problem?
Well, until now, it’s been difficult to assess. Testing methods vary from lab to lab, approaches vary region to region. Do we use data based on where neonicotinoids are sold? How do we know if they were applied? Do we test soil? Bees? Hives? Honey? Recently, scientists from Universities in Canada and Switzerland put out a call for honey samples taken directly from hives through a citizen-science project. They received nearly 200 samples from six continents, and for the first time were able to apply standardized testing, and using the same protocol, to generate a worldwide map of neonicotinoid use.
What did the study find?
- 75% of the samples tested, some from populated areas, some from remote areas, tested positive for the insecticide
- Every continent except Antarctica has significant exposure to neonicotinoids
- Nearly half the samples contained neonicotinoid levels, on the basis of previous research, thought to impair bees’ brain function and slow the growth of their colony
- 45% of samples tested positive for more than one type of neonicotinoid
- Honey collected in North America had the highest proportion of samples containing at least one neonicotinoid, at 86%, with Asia (80%) and Europe (79%) close behind
- Contamination was discovered in honey even from remote places — including islands in the middle of the Pacific Ocean and off the coast of West Africa
- Bees the world over are exposed to neonicotinoids constantly over generations, which is concerning because their primary (only) food source is honey – it’s one thing to have one bad meal, and another entirely to have everything you eat be contaminated
Widespread presence of neonicotinoids is not surprising, since they are used on staple crops like wheat and canola, as well as in home gardens (residential gardens cover more acreage than agriculture in the U.S.), but the map helps quantify the problem by region.
So what now?
This study contributes to the discussion substantially, now we can monitor the change of neonicotinoid use over time, and assess how problematic low level exposures are to bees over a long period of time.