Roundup Weedkiller vs Honey Bee Populations

By - March 30, 2019
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Pound-for-pound, no creature contributes more to agriculture than the honey bee. Actually, that should probably be 0.00025 pound-for-0.00025 pound, since that’s the weight of a typical honey bee. A single bee colony can pollinate 300 million flowers each day, and bees are responsible for about 80% of pollination worldwide.

That’s why the still not-fully-understood massive die-off of bee populations, both wild and managed colonies, has sparked concern all over the globe. There are about 100 food crops that provide nearly all human nutrition, and bees pollinate 70% of those. Humans would, quite literally, starve without bees.

Several factors have been scientifically determined to at least be contributors to colony collapse, including:

  • Parasites
  • Pathogens
  • Habitat loss
  • Poor nutrition

But there’s one factor in particular that many environmental activists and researchers have increasingly grown to recognize as a major contributor — the widespread use of herbicide, pesticide and insecticide in major agricultural operations.

For about 10 years now, research has consistently found that agricultural chemical residue is present in honey bees, with one study finding such residue in two-thirds of the U.S. and Canadian bee populations surveyed. (Source)

More recently, a study has linked glyphosate, the active ingredient in the controversial Roundup weedkiller, to disease and death in bees. Two juries so far have ruled that glyphosate causes or contributes to non-Hodgkin lymphoma, a type of cancer.

What chemicals have been detected in bees, how do these substances impact the health of bees and what can be done to ensure the safety of these workhorses of nature?

What Researchers Have Found

For well over 10 years, scientific researchers have detected residue of dozens of agricultural chemicals in honey bees and/or the honey they produce, and many of those studies have linked the chemical residue to disease and death in bees.

Here’s a look at just some of the research that’s been done in this area:

Study 1

  • A 2019 French study found a Bayer-produced insecticide, flupyradifurone (known commercially as Sivanto), particularly when combined with the fungicide propiconazole, harms and kills honey bees. (Bayer also produces Roundup.)

Study 2

  • University of Texas researchers in 2018 found that glyphosate, the active ingredient in Roundup, disrupts the gut bacteria of honey bees.

Study 3

  • In 2017, a study found at least one neonicotinoid (imidacloprid, thiacloprid, acetamiprid, thiamethoxam and clothianidin) in 75% of honey samples, with the highest concentrations coming from North American samples.

Study 4

  • A 2018 study led by a Harvard professor finds that neonicotinoids disrupt normal, healthy bee behavior, including nursing and caretaking behaviors, threatening colony viability.

Study 5

  • A study in 2015 found that wild bees were exposed to nearly 20 agricultural chemicals, including neonicotinoids as well as the controversial insecticide chlorpyrifos and the herbicides atrazine and metolachlor.

Study 6

  • Glyphosate was determined to disrupt bees’ ability to navigate safely back to their hives, which threatens colonies’ populations in a 2015 study.

Study 7

  • Inactive ingredients in agricultural chemicals are particularly toxic, in many cases even more than the active ingredients, according to a 2015 study, which also found that these inactive ingredients rarely are studied or even listed.

Study 8

  • Agrochemicals, including glyphosate, were found in a 2010 study to cause midgut cell death in bee larvae.

Study 9

  • Exposure to chlorpyrifos reduced queen emergence in bee colonies in a 2012 study.

Study 10

  • A 2015 study found that more than 40 commonly used chemicals, including glyphosate, were found to kill foraging honey bees.

Bayer, Monsanto & Bees

Multiple studies have connected herbicides, specifically glyphosate, to negative health effects and death of bees, including disrupting gut bacteria and making the insects more susceptible to death and interfering with their natural ability to return to the hive.

In addition to first bringing glyphosate to the market, Monsanto (and its parent company Bayer AG) also produce several neonicotinoids (sometimes referred to as neonics), which are neuroactive insecticides that are chemically similar to nicotine. The most widely used of these insecticides is imidacloprid, which Bayer produces and which has been linked to disease and death of bees.

Members of the European Union have moved to nearly completely ban neonics, and until 2018 the use of these chemicals was not allowed in the handful of U.S. wildlife refuges where farming is permitted, but the Trump administration rolled back that bad in August 2018. Bayer has repeatedly said that neonicotinoids are safe for non-targeted insects when used according to the label instructions, but as we’ve already shown, there is overwhelming scientific evidence that this assertion simply isn’t true.

Similarly, Bayer and Monsanto have for years touted the safety of glyphosate, but the scientific, legal and regulatory chorus is growing against that dangerous chemical, too.

Glyphosate & Bees

Let’s take a closer look at the studies connecting glyphosate to disease and death in bees. Combatting the misinformation spread by deep-pocketed Bayer and Monsanto means being well-informed on what studies have found.

Gut health

The most recent study published on the fatal connection between glyphosate and bees was the 2018 study by University of Texas researchers that found Roundup’s active ingredient caused honey bees to lose some of the beneficial bacteria in their guts, which made them more susceptible to disease and eventually death.

For years, Monsanto (and now Bayer, which recently purchased Monsanto) have said that only the plants treated glyphosate can be harmed because the chemical targets a specific enzyme that exists only in plants and not in animals or humans. But this enzyme is also found in the gut microbiome of most bee species, and the study found that exposing bees to glyphosate increases their risk of becoming sick and dying.

The study also concluded that the levels of glyphosate detectable in our current environment are enough create the gut health disruption researchers found in bees exposed to glyphosate. In other words, one need not reproduce lab conditions to see this effect in bees.

Separately, a 2010 study conducted using bee larvae found that several agrochemicals, including glyphosate, increased apoptosis, or cell death in the midgut of the larvae. Glyphosate killed nearly 70% of the midgut cells.

Foraging bees

A 2015 study determined that adult, foraging honey bees could be killed on contact with pesticides, herbicides and insecticides, including glyphosate, sprayed on crops or could survive but carry contaminated pollen back to their hives.

While glyphosate was determined to be one of the 42 chemicals toxic to bees, the study also included neonicotinoids, which are, of course, designed specifically to kill insects.


In 2015, researchers found that less-than-lethal doses of glyphosate residue impaired the cognitive capacity of honey bees. The study found concentrations of glyphosate equivalent to what’s typically found in farming settings impaired bees’ brains, limiting their ability to interpret the spatial information needed to safely return to their hives. Bees that were able to return took longer trips to get there, and some were unable to return at all.

Why We Need Bees

They might disrupt your picnic, but bees are crucial to the global ecosystem, and many species of bees are critical to agriculture. The bee’s centrality to farming will become even more critical as the population of our planet continues to grow and farmers are pressured to produce even more crops to feed all of those people.

While the likes of Monsanto and Bayer would surely tout their dangerous chemicals as the best tool for increasing crop yields, ensuring the health of pollinators is the more sustainable and safer way to feed everyone. In addition to impacting crop production, bees are crucial to the dairy and beef industries, since bees pollinate many of the crops that feed livestock, including hay and other forage crops.

Honey bees contribute more than $15 billion to the U.S. agricultural economy every year thanks to the diversity of crops they’re responsible for pollinating. Many crops rely almost entirely on bees for pollination, including almonds, 90% of which are pollinated by bees. In addition to managed bee colonies that pollinate farm crops, native bee populations provide a more than $9 billion impact.

How pollination works

Bees are not the natural world’s only pollinators, but they are the most prodigious. Many other animals and insects, including flies, butterflies, bats and birds, also help pollinate plants. So what is pollination? Pollination is the transfer of pollen from one plant to another to cause fertilization and seed production. This can happen naturally when the wind blows, but often an animal or insect will transfer the pollen.

In the case of bees, this can happen when the bee visits one plant to eat its nectar. In doing so, the bee gets some of the plant’s pollen on its legs. It will then move on to another nearby plant and deposit some of the pollen while it feeds on the second plant.

If plants aren’t pollinated, they don’t produce seeds and once the individual plant dies, there won’t be any to replace it.

We need more food

There is no one cause of colony losses and reduction of wild bee populations, which is why it’s so critical to study and understand all of the factors that contribute. But whatever the myriad causes, figuring out how to stabilize bee populations may well be critical to securing the success and safety of our species.

Food demand is projected to increase by as much as 90% through 2050, and experts have said that our planet will need to produce more food in the next 40 years than has been produced in the previous 10,000 combined.

Without pollination from bees, crop yields will fall at the very time we need them to increase.

What You Can Do

There’s no doubt the best way to stabilize bee populations is through action on the national level, but that doesn’t mean that an individual can’t have an impact. Here are a few steps a concerned individual can take:

  • Avoid non-organic pesticides, herbicides or insecticides in your yard, and (if you can) boycott products made with harmful chemicals.
  • Shop local and eat organic.
  • Plant flowers that bees love (sunflowers, lavender and daisies all are favored pollinator targets).
  • Allow part of your lawn to have dandelion and clover, which bees love. If you have nosy neighbors, this may be difficult, but there’s a reason you don’t see bees around golf courses — they don’t care about well-manicured lawns.
  • Pressure your local and state representatives to ban certain chemicals, including chemicals like glyphosate and neonicotinoids.
  • Encourage bees to be part of your property or buy a bumble bee house or plant a bee garden!
  • Sponsor a hive or become a bee ambassador
  • Support your local beekeeper


Despite Bayer and Monsanto would want consumers and lawmakers to believe, the evidence is substantial that glyphosate and other products the company makes are dangerous, not only to humans but to the natural world.


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