June 22, 2021

I, Science

The science magazine of Imperial College

Bee colonies are increasingly falling victim to colony collapse disorder. Its time we understood the causes and took action to protect this vital species.

Bees have been around for a long time, however, modern businesses, policies and food regulations are drastically threatening their existence. It is time we understood and addressed these threats to ensure the survival of this vital species.

Bees evolved alongside flowers roughly 150 million years ago1, in one of the most rapid developments of a species’ biodiversity in history – a progression that Charles Darwin called a “most perplexing phenomenon”.

Today these two classes of species cover much of the planet, found in jungles and grasslands alike. Around 80% of all flowers, or 250,000 species require bee pollination to breed2, this includes a large number of crops grown for human consumption; apples, blueberries, avocados, cashew nuts and chocolate are all plant varieties that rely on bee pollination.

Yet due to the appearance of colony collapse disorder (CCD), bees numbers are falling rapidly. CCD is characterised by the complete abandonment of a colony by adult bees, leaving larvae, food stores, cells and often the queen to decompose. CCD has claimed over 10 million hives in the last six years alone3, and led to the death of an estimated quarter of a trillion bees since the 90s, according to Dr Reese Halter, an expert on biological conservation in the US. Yet ten years on and the United States Department of Agriculture (USDA) concede that “there is no single factor or pattern of factors that have been proven to be ‘the cause’ of CCD”.

Finding a Cause

Some commentators have dismissed the impact of CCD, citing the apparent stability of commercial bee populations. Yet this is misleading, as the commercial bee population is only being kept ‘stable’ due to beekeepers working overtime to replenish their lost colonies in an attempt to preserve their livelihood. The reality is that beekeepers are losing hives at a rate of more than double that of twenty years ago. It is estimated that last year around 44.1% of beekeepers’ hives were lost in the US4.

honey bees

Lost colonies, an increasingly common sights for beekeepers. Image Petch.

Scientists have been attempting to determine the cause of CCD for several years, and have concluded, despite the USDA’s confusion, that falls in bee health are linked to insecticide use; In particular, neonicotinoids. These chemicals, also known as neonics, have carved out a one-billion-Dollar industry in their decade of popular use and are now a standard offering from the agrochem companies.

To make a plant insect resistant, neonics are applied to the seed before plantation; as the crop grows the chemicals distribute systemically through its vessels5. Insects are either affected by the airborne neonics around the plant, or by consuming its nectar or flesh. Even in tiny doses the chemical triggers neuronal and nerve responses, causing the insects to convulse and paralyse until death.

A plethora of studies have shown that neonicotinoids are directly harmful to bee health, reducing their life expectancy by over a third6, reducing foraging distance, and even causing bees to tremble excessively before perishing7.

More on Neonicotinoids

Anecdotal reports from farmers, who have observed the action of neonicotinoids, support these studies. In Ontario Canada for instance, 37 million bees dropped dead over the course of a week in 2014, when a new neonicotinoid treated GM corn crop was planted. Farmers have reported staggering losses near similarly treated crops. Farmer James Murray, who planted a neonic crop, lost seventeen hives and a million bees: “I thought that was odd. All the bees were shaking… This is why the beekeeping industry is dying…[The use of neonicotinoid-treated seeds] needs to be reduced”.

Fortunately neonics are heavily regulated in England, following an EU ban in 2013 after concerns about their ecological impact, particularly on pollinators. However, rapeseed oil crops in the UK do utilise neonic seed treatments. A large scale study investigating 1,818 surveys across more than 4,000 square kilometres of land found that bee populations associated with the crop fell considerably, some by over 30% in less than a decade8. An Imperial College study by biologist Richard Gill also found a direct link between diminished bee numbers in hives and neonicotinoid exposure.

Yet neonicotinoid usage in the US is growing, and could well do so in the UK too following Brexit, because the EU ban was originally opposed by the UK government.

To understand why the chemical is so prevalent, despite its demonstrated effect on bees, it’s necessary to consider the economic state of the insecticide and seed market.

The Industry

Three corporations manufacture most neonic treated seeds: Monsanto, Syngenta and Dupont. Between them they hold just under 50% of the world seed market, and almost all of the US seed market.

All three corporations deny that neonicotinoids impact bee health when used “responsibly”. What constitutes responsible use when around 10-9g (a billionth of a gram) doses of neonics have been shown to kill bees within a few hours is not entirely clear at present9. And sure enough no spokesperson from any of the three companies has conceded the relationship between their products and bee health, nor have they offered a methodology for safe use.

people protesting GMO's

Protestors march against Monsanto and Syngenta in Basel, May’16. Image lucarista.

There is little evidence to indicate that the big agrochem companies intend to roll back their neonic usage in light of dwindling bee numbers or scientific studies. Whether farmers will discontinue their use is hard to say, but in some cases farmers have no choice but to use seeds sold by the big three.

This is a fact Angelika Hilbeck, senior scientist at the Institute of Integrative Biology at ETH Zurich, unearthed in a study of worldwide seed catalogues and buying rights. She noticed that farmer choice was diminishing considerably in the US, where there are states in which 50% of farmers report having almost no choice of seed, apart from the GM variety offered by elite level agrochem companies.

Iowa farmer George Naylor says he has trouble finding non-GMO soybean seeds: “Some seed companies don’t offer any. One company’s soybean seed line-up is all Monsanto’s Roundup Ready (seeds).” Roundup Ready 2 being one of Monsanto’s highly successfully herbicides, for use with their GM seeds.

As neonic seeds become more prevalent their use may be as tied to the staple GM seeds as roundup and other herbicides/pesticides offered by the big three. Package deals are economical for both parties.

The neonic problem, and the question of tackling it, is proving far more complex than simply publishing science showcasing its negative effects. So long as they’re profitable neonics may be around for some time.

As for their usage in the UK, it’s entirely possible that neonics may become more widespread following Brexit. If so, bee-conscious consumers would do well to watch this class of insecticides, against which the only current defence is to buy organic food.

Zeb Mattey is studying for an MSc in Science Communication.

Banner Image: Bee pollinating flower, Lumppini