Written by Orla O’Callaghan, Colorado Master Gardener and Colorado Native Plant Master
You have probably noticed that honey bees are in the news a lot of late with people raising the alarm over their declining numbers. So what is going on?
The number of European honey bees (Apis mellinfera) in the U.S. has been declining for decades; between 1947 and 2008 the numbers of honey bee colonies dropped by six-one percent. During the winter it is not uncommon to lose 15% of the bees in a colony, and have the colony bounce back in the spring and summer. But the bees were declining in much greater numbers.
There are re many reasons for these declines, including:
- Mites – Since the 1980s, the invasive bloodsucking Varroa mites (Varroa destructor) have caused bee colony declines. The mites weaken the bees and spread viruses.
- Viruses – The Israeli Acute Paralysis virus and the deformed wings virus are killing bees.
- Diseases – American Foulbrood (AFB) is an infectious bacterial disease that can spread quickly and kill the immature bees in their larvae stages.
- Parasites – The honey bee tracheal mite (Nosema ceranae) has been killing bees.
- Crop Pesticides – Pesticide poisoning, or sub-lethal negative effects due to chronic exposure to pesticides applied to seeds or crops has been linked to bee declines.
- Hive Pesticides – Pesticide poisoning, or sub-lethal negative effects due to chronic exposure to pesticides applied to control mites and other insects in the hive have also been linked to bee declines.
- Stress – Certain management practices, such as commercial beekeepers transporting their hives long distances multiple times in the year while providing pollination services, and splitting hives more often is placing stress on the bees. Transportation can also aid the spread of viruses and mites.
- Lack of Food – Inadequate forage, poor nutrition and starvation are factors in declining bee numbers. This is problem is becoming more of an issue with urban development, big farms with vast swaths of mono-cultures, and global warming.
- Suppression of the bee’s immune systems, which weakens its ability to deal with the above mentions threats.
- In the past, the retirement of commercial beekeepers has reduced the number of bee colonies in the United States. This factor is being countered by the increased popularity of beekeeping.
If honey bee numbers have been declining since the 1940s why are we just hearing about it in recent years?
Good question! During the winter of 2006-2007, bees made the news because something new was happening causing huge losses of bees. Bee keepers were experiencing drastic sudden losses of 30 to 90% of the bees in their colonies. Not only was the extent of the loss different than before, but so was the nature of the decline. Large numbers of worker bees were rapidly disappearing from the hives. They would leave the hive and not return. Unlike declines in the past, there were very few, if any dead bodies of worker bees in or around the hive. Remaining in the hive was the queen and some nurse bees with a capped brood, and plenty of food (pollen and nectar). Hives cannot survive without worker bees to sustain them. This new type of colony decline became known as Colony Collapse Disease (here after CCD)
In 2007, CCD was found in North and South American, Europe, and Asia. In the U.S., over the next six years’ annual winter bee colony losses increased from 15% to up to 43.7%. In 2008, roughly 60% of colony losses in the winter were due to CCD.
So what have scientists figured out about CCD so far?
The cause of CCD is unknown. Scientists cannot attribute a single cause of CCD. CCD is likely a result of a combination of the factors I listed above. Colonies affected by CCD show elevated levels of pathogens and pesticides are present in the wax and pollen. Scientists believe that pesticides, particularly neonicotinoids (active ingredients imidacloprid, clothianidin and thiametheoxam) have been shown to have a sub-lethal but long term effects on honeybees. Neonicotinoids are used on most corn, wheat, soy and cotton grown in the United States. The pesticides work their way up the plant and get into the pollen and nectar that the bees feed on.
The pesticides can remain in the soils for up to two years after application. Treated seed are covered in a talc, to help them disperse easily from the seeding machines. The pesticide gets into the talc and is dispersed into the environment. Continual exposure to the pesticides affects the bees foraging behavior, memory and ability to learn. It can lower the bee’s immune system making them vulnerable to mites, fungi and other pathogens. It can also cause the bees to become disoriented, which may cause them to become lost, preventing them from returning to the hive. Bees can exhibit tremors, uncoordinated movements or convulsions due to pesticide poisoning. The pesticides can also reduce the reproductive capacities of the queen reducing egg production. A study found that neonicotinoids become addictive to bee. Other studies suggest these pesticides are having a negative impact on birds, aquatic invertebrates and other wildlife. Neonicotinoids are also found in food humans eat, including honey and baby food.
In addition to pesticides leading to bee colony declines, a study by the University of Texas found that honey bees exposed to weed killers containing glyphosate, lose some beneficial gut bacteria making them more susceptible to infections.
What is being done to help the bees?
In response to CCD the U.S. established a task force to address CCD and passed several Farm Bills providing funding for bee conservation. In 2014, the Obama administration issued a blanket ban on the use of neonicotinoids. In 2016, seven yellow faced bee species, native to Hawaii, were placed on the Endangered Species List. In 2017, the Rusty-patched bumblebee (Bombus affinis) was added to the list. Unfortunately, in 2018, the Trump administration reversed the ban on neonicotinoids removing legal protections of bees. In 2018, Maryland and Connecticut had banned neonicotinoids in the state. In 2019, the Environmental Protection Agency (EPA) halted the approval of any new use of neonicotinoids, and banned twelve new neonicotinoid pesticides. Existing pesticides containing neonicotinoids were still legal to sell for currently licensed uses. In 2018, the European Union enacted a total ban the use of neonicotinoids, except in closed greenhouses. Canada has passed several regional bans.
Why should we care about declining honey bee numbers?
Do you like to eat food?
Honey bees pollinate over 250,000 species of flowering plants, including around 100 cash crops in the United States. The following foods are pollinated by bees:
Fruits: Apples, Mangos, Kiwi, Plums, Peaches, Nectarines, Guava, Cherries, Pomegranates, Pears, Apricots, Passion Fruit, Lychees, Figs, Watermelon, Cantaloupe, Quince, Star fruit, Grapes, Persimmons, Papaya, Citrus Fruits (Lemons, Limes, Tangelo, Tangerines) and Rose Hips.
Berries: Black and Red Currants, Strawberries, Raspberries, Elderberries, Boysenberries, Cranberries, and Blackberries.
Grains, Grasses and forage: Alfalfa, Buckwheat, and Clover.
Vegetables: Okra, Onions, Prickly Pear, Broccoli, Cauliflower, Cabbage, Brussels Sprouts, Bok Choy, Avocados, Cucumber, Celery, Carrots, Beets, Turnips, Eggplant, Black Eyed Peas, Tomatoes, pumpkins, squash, broccoli, and peppers (Chili peppers, Red Peppers, Bell Peppers, Green Peppers) and many types of Beans (including Lima, Kidney and Green).
Nuts: Cashews, Walnut, Macadamia, Almonds, Hazelnut, Brazil, Chestnut and Coconut.
Sources of Oils: Sunflower Oil, Palm Oil, Rapeseed, and Sesame
Herbs and Spices: Fennel, Coriander, Caraway, Mustard Seed, and Tamarind
Other: Cotton, Safflower, Cocoa, and Vanilla
While I could live without Okra and Bok Choy, I would miss most of the rest of the flowers and foods. Loss of honey bees would lead to food insecurity and worst case scenario mass extinction.
Before these worst case scenarios, declining bee numbers mean higher food prices. As the costs of commercial beekeepers’ rise, they have to charge producers more for their pollination services, and that cost is passed onto consumers.
Do you like a strong U.S. Economy, wear make-up, burn candles, or take medicine?
Honey bees are money makers for U.S. Agriculture, providing 15 billion in added crop value. Honey bees produce the following products:
- Commercial Pollination Services – In 2017, commercial pollinators collectively earned an annual income of $435 million.
- Honey – In 2016, honey bees produced around 163 million pounds of honey valued around $339 million dollars.
- Bees wax – Bees wax is used in candles, cosmetics, art supplies, leather and wood polishes, and as binding agents and time-release mechanism in medicines. In 2017, the global market value of bees wax was $470 million. It is forecasted to reach $620 million by 2025.
- Pollen – Bee pollen is used medicinally.
- Royal jelly – Royal Jelly is a secretion from nurse bees used to feed the bee larvae and the queen. It is used in cosmetics and medicinally.
- Propolis – Propolis is a resinous substance worker bees collect from tree buds. They use it to fill crevices in the hive and to seal the honeycomb chambers. Humans use it in cosmetics and medicinally.
- Venom – Bee venom has been used to de-sensitive people who are highly sensitive to bee stings. It has also been used in cosmetics and medicinally.
What can you do to help the honey bee?
Buy organic produce and breads. Don’t use pesticides with neonicotinoids or herbicides with glyphosate. Plant with bees in mind; do organic gardening. Increase the diversity of plants in your garden and neighborhood. Plant flowers that bees like that bloom early and late when food is scarce, plants such as yellow current, rabbit brush, golden rod, and common and Maximillian sunflowers and asters. For a more extensive list of plants for bees, see Extension fact sheet 5.615 Attracting Native Bees to your Landscape and 5.616 Creating a Pollinator Habitat or see list at www.magicvalletbeekeepers.org.
Leave your untreated dandelion blooms in your yard. Manually remove the heads before the seeds disperse. Dandelions are an important early source of forage for bees. Help plant community gardens to create a food corridor for bees. Get involved in a local beekeepers group, get educated, and become a beekeeper yourself. In Pueblo, check out the Pueblo County Beekeepers Association. Talk to your politicians about protecting bees and vote.
Are we all going to die because of disappearing honey bees?
We will probably survive. Despite CCD, the number of honey bee colonies in the U.S. has remained relatively stable, namely because there are more people keeping bees, and commercial beekeepers are splitting their hives more often (in the spring and summer) and buying bees from other countries. These are only stopgap measures for now.
The European Honey bee is the most common pollinator, but there are other bees that could be used to pollinate crops if need be. Beekeepers are looking into utilizing other bee species to pollinate crops: Bumble bees (Bombus sp.), Alfalfa Leafcutting bees (Megachile rotundata), Alkali bees (Nomia melarideri) and Blue Orchard/Mason bees (Osmia sp.). Use of these bee species are more costly and would increase food prices.
Scientists are working on robotic bees to pollinate plants. Wal-Mart even took out a patent for a robotic bee. Yes, as crazy as this all sounds, it is true. They have not perfected these robotic bees yet.
I am hopeful that laws will be re-enacted to protect honey bees and other pollinators before they are gone and we have to rely on robo-bees.