You have likely heard of a new beekeeper starting because they want to “Save the Bees.” Perhaps you are mentoring someone who started for that reason. Or you have had the discussion about honey bee colony losses and been asked the question, Are bees going extinct? As we start gearing up for a new spring start-up season, how should we respond to these inquiries and concerns?
Marla Spivak in the October ABJ discussed the “double-edged swords” beekeepers face. One was the conundrum of individuals starting beekeeping to save the bees but then not properly caring for their bees. Some simply don’t know how, but some also have the mistaken belief that by not treating or feeding colonies, bees will be hardier and build resistance to mites/disease. They didn’t really want to keep bees, just save them.
Our best response is to say No — honey bees are not going extinct. While we do have high annual colony losses, honey bees will not all die if we take proper care of them. We need to continue to rely on managed honey bee colonies for as much as a third of the food we eat.
Colonies suffering high mite numbers, the syndrome we call Parasitic Mite Syndrome (PMS) or Parasitic Mite Brood Syndrome (PMBS), may have died in the fall and more will die over winter. Such losses are the “new normal,” although losses are double or more what we expect. Individuals who have kept bees for a while, understand that the rate of colony loss in Europe and North America nearly tripled after the arrival of varroa in the 1970s and 1980s. (Ellis, J.D, Evans, J.D, and J. Pettis 2010. Colony losses, managed colony population decline, and Colony Collapse Disorder in the United States. J, Apic Res 49: 134–136.)
We realize it is not the mites per se but rather their transmission of viruses, primarily Deformed Wing Virus (DWV), that leads to the heavy loss of honey bee colonies. Without treatments for varroa, honey bee colonies almost always die within two or three years. (Fries I, Imdorf A, Rosenkranz P. (2006) Survival of mite infested (Varroa destructor) honey bee (Apis mellifera) colonies in a Nordic climate. Apidologie 37: 564–570.)
We may assume losses in the spring to be caused by starvation or too small a population, but both might actually be indirectly due to varroa mites the previous season. Splits and swarm capture losses, along with feral hive transfer losses, are close to 50%, despite our best efforts to properly start the new colonies. We lose more package- and nuc-established colonies during the winter than we do previously overwintered colonies. I document these percentage differences for the Pacific Northwest region in an annual survey (https://pnwhoneybeesurvey.com).
Langstroth in his first edition of the “Hive and the Honey Bee” mentioned the high losses by beekeepers over winter. Introducing his new hive, he advised beekeepers to take losses in the fall by combining weaker units and those with too little stored honey to survive. He said this was especially important with new colonies. Managing bees means heavily feeding newly-established colonies sugar syrup and protein supplements to improve chances of survival.
Colony Numbers are Growing
The number of bee colonies is actually growing in the U.S., fueled by the demand for colonies to pollinate almonds. That may change as water availability will lead to major changes in almond cultivation. Each tree needs water — a lot of water. It is estimated each almond takes 1.1 gallons of water; to grow a pound of almonds takes 1,900 gallons. Although almond water use has been singled out, other tree crops such as walnuts, hazelnuts, pistachios, and cashews all use roughly the same amount of water. Animal culture is similar. It is estimated that it takes 1700 gal/lb. of water to raise beef cattle.
We know our colonies have multiple stressors and bees are not as healthy as they need be. Beekeepers across the United States lost 45.5% of their managed honey bee colonies from April 2020 to April 2021, according to preliminary results of the 15th annual nationwide survey conducted by the nonprofit Bee Informed Partnership (BIP). Yet despite annual losses averaging over 30%, colony numbers are increasing in North America, Europe and worldwide.
In part colony loss statistics are related to what time frame you pick. The total number of managed honey bee colonies decreased from an estimated 5 million in the 1940s to a low of 2.4 million in 2006 when the term CCD (Colony collapse Disorder) was coined. Since that period, it has climbed to an estimated 2.71 million today, according to the most recent (2020) USDA-National Agricultural Statistics Service (NASS) survey (NASS, March 2021 Honey).
Statistics Canada reports the total national colony count of colonies in Canada has increased by 26.7% during the period 2007-2020. This is double the U.S. rate of increase. Total colony number currently is estimated at around 725,000 colonies. Globally the numbers of managed honey bee colonies have risen 85% since 1961, mainly with increases in honey bee colonies in Asia.
Loss of diversity in bees
While high seasonal honey bee losses are being replaced, of greater concern is an apparent loss of diversity in native (sometimes termed wild) populations of non-managed bees and other pollinators. We are justifiably concerned expanding the term “bees” to include native or wild bees. Studies of native bee species, their overall abundance and distribution in general, and their ecosystem service of pollination has in some instances documented bee populations that are not as healthy or robust as they once were. (Zattara, E.E. and Aizen , M.A. 2021. Worldwide occurrence records suggest a global decline in bee species richness. One Earth 4:114-123.)
One of the challenges in documenting loss of bee diversity is a lack of records of earlier abundance. The media have picked up on declines in insect abundance and coined the term “insect apocalypse” (https://www.nytimes.com/2018/11/27/magazine/insect-apocalypse.html). Some readers may recall that after CCD was identified, “bee apocalypse” was used for the plight of the honey bee. The declines appear genuine even if we can’t document them precisely.
There are approximately 4000 species of bees in the U.S. and some of these may be disappearing as flowering plants and habitat that they rely on are removed. This seems to be the situation with documented instances of decreasing populations of bumble bees, the next most common bee recognized after honey bees. Minnesota recently made the rusty patched bumble bee their State Bee to call attention to loss of bees. While once common over a large area, this species is no longer common. Other bumble bees are also apparently less common although some were never common to begin with.
Among other pollinators, the annual migration of monarch butterflies has been cited as evidence of habitat loss. Losses approaching 80% have put monarchs on the waiting list for Endangered Species Act listing. (Center for Biological Diversity: “Eastern Monarch Butterfly Population Falls Again,” February 2021.) To expand from overwintering sites in Mexico and along the California coast, successive generations of monarchs need certain types of milkweeds to grow another generation to move further northward before retreating back southward each fall. Species that have specific plant needs for food or reproduction, or to complete their life, have diminishing chances of continued survival with habitat loss. Honey bees are generalist feeders, although they need a variety of pollen and nectar sources to prosper. The vast majority of other pollinators, like monarch butterflies and native bees, are much more restricted in their diet.
Could our food supply be in danger? A recent survey identified a mere 66 species of insects that are or could be used in planned pollination. Eighty-seven of the 107 leading crops are dependent upon insect pollination. Included are seven species of bumble bees, mainly used for greenhouse production, although commercially-propagated bumble bees may be useful in some field-grown crops like blueberries. Eight species of wild bees are used in orchard and alfalfa production.
Worldwide the growth of pollination-dependent agriculture crops is increasing disproportionally to other non-insect-pollinated crop expansion. Most of the rest of the species listed as useful in agriculture are only identified as potentially useful. This accounting does not ….