Honey Bee Colony Losses 2018-2019: Preliminary Results

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JUNE 19TH, 2019

Note: This is a preliminary analysis. Sample sizes and estimates are likely to change. A more detailed state-specific report, as well as a manuscript for submission to a peer-reviewed scientific journal, will follow at a later date. 

The Bee Informed Partnership (BIP; http://beeinformed.org) recently conducted the 13th annual survey of managed honey bee colony losses in the United States. This past year, 4,696 beekeepers collectively managing 319,787 colonies as of October 2018 provided validated colony loss survey responses. The number of colonies managed by surveyed respondents represents 11.9% of the estimated 2.69 million managed honey-producing colonies in the nation (USDA, 2018).

During the 2018-2019 winter (1 October 2018 – 1 April 2019), an estimated 37.7% of managed honey bee colonies in the United States were lost (Fig. 1). This loss represents an increase of 7 percentage points compared to last year (30.7%), and an increase of 8.9 percentage points compared to the 13-year average winter colony loss rate of 28.8%. This year’s estimate is the highest level of winter losses reported since the survey began in 2006-2007.

Similar to previous years, backyard beekeepers lost more colonies over the winter (39.8%) compared to sideline (36.5%) and commercial (37.5%) beekeepers. Backyard, sideline, and commercial beekeepers are defined as those managing 50 or fewer colonies, 51 to 500 colonies, and 501 or more colonies, respectively.

Our survey also asked what level of winter loss would be acceptable by beekeepers. Interestingly, this revealed an increase from 20.6% last year to 22.2% this year, which is much greater than the 11-year average of 17%. This increased acceptable loss may indicate that beekeepers are more realistic or pragmatic in their expectations of colony losses. Even with a higher acceptable loss, sixty-two percent of responding beekeepers lost more colonies than the level deemed acceptable.

During the summer 2018 season (1 April 2018 – 1 October 2018), an estimated 20.5% of managed colonies were lost in the U.S. This level is slightly higher (3.4 percentage points) than the previous summer’s colony loss estimate of 17.1%, but is on par with the summer loss average reported by beekeepers since 2010-2011 (20.5%), when summer losses were first recorded by the BIP.

For the entire survey period (1 April 2018 – 1 April 2019), beekeepers in the U.S. lost an estimated 40.7% of their managed honey bee colonies. This is similar to last year’s annual loss estimate of 40.1%, but slightly higher (2.9 percentage points) than the average annual rate of loss reported by beekeepers since 2010-11 (37.8%).

We note that loss rate for each period was estimated by identifying the total number of at-risk-colonies that died, and that annual loss rate was not estimated by summing the individual summer and winter loss rates. This year’s state-specific loss rates will be added to previous years’ results on the BIP website shortly (https://bip2.beeinformed.org/loss-map/).

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Fig 1. Total winter colony loss rate in the United States across years of the Bee Informed Partnership’s National Honey Bee Colony Loss Survey (yellow bars; 1 October – 1 April)1. Total annual loss estimates (orange bars) include total winter and summer (1 April – 1 October) losses; the latter has been estimated since 2010-2011 only. The acceptable winter loss rate (grey bars) is the average percentage of acceptable winter colony loss declared by the survey participants in each year of the survey.

 1Previous survey results estimated total winter colony loss values of 31% in the winter of 2017-18, 21% in 2016-17, 27% in 2015-16, 22% in 2014-15, 24% in 2013-14, 30% in 2012-13, 22% in 2011-12, 30% in 2010-11, 32% in 2009-10, 29% in 2008-09, 36% in 2007-08, and 32% in 2006-07 (see reference list).

https://beeinformed.org/results/2018-2019/

More Bad Buzz For Bees: Record Number Of Honeybee Colonies Died Last Winter

NPR The Salt By Susie Nielsen June 19, 2019

Honeybee hives stand on a field at the Central Maryland Research and Education Center in Beltsville, Maryland. An annual survey of U.S. beekeepers shows the rate of colony death last winter — nearly 40% — was the highest reported since the survey began 13 years ago.  Olivia Falcigno/NPR

Honeybee hives stand on a field at the Central Maryland Research and Education Center in Beltsville, Maryland. An annual survey of U.S. beekeepers shows the rate of colony death last winter — nearly 40% — was the highest reported since the survey began 13 years ago. Olivia Falcigno/NPR

It's a sweltering morning in Beltsville, Md., and I'm face-to-face with bee doom. Mark Dykes, a "Bee Squad coordinator" at the University of Maryland, shakes a Mason jar filled with buzzing honeybees that are coated with powdered sugar. The sugar loosens the grip of tiny Varroa mites, a parasite that plagues bees; as he sifts the powder into a bowl, they poke out like hairy pebbles in snow.

"Right now there [are] three mites per hundred [bees]," says Dennis vanEngelsdorp, associate professor of entomology at the University of Maryland and president of the Bee Informed Partnership, which studies bee survival rates. That's a high rate of mites, vanEngelsdorp says: "If this were September and you were seeing that number, you'd expect the hive to die" during the lean months of winter.

Varroa  mites, tiny pests that can weaken and destroy honeybee colonies, are on display in a small jar.  Olivia Falcigno/NPR

Varroa mites, tiny pests that can weaken and destroy honeybee colonies, are on display in a small jar. Olivia Falcigno/NPR

Bee colony death continues to rise. According to the Bee Informed Partnership's latest survey, released this week, U.S. beekeepers lost nearly 40% of their honeybee colonies last winter — the greatest reported winter hive loss since the partnership started its surveys 13 years ago. The total annual loss was slightly above average.

The survey included responses from nearly 4,700 beekeepers managing almost 320,000 hives, making up about 12% of total managed honey-producing colonies in the United States.

Bee decline has many causes, including decreasing crop diversity, poor beekeeping practices and loss of habitat. Pesticides weaken bees' immune systems and can kill them. Varroa mites (full, ominous species name: Varroa destructor) latch onto honeybees and suck their "fat body" tissue, stunting and weakening them and potentially causing entire colonies to collapse.

Honeybees crawl through a modern-day hive. This past winter saw the most dramatic losses of managed honeybee colonies in 13 years, according to researchers.  Olivia Falcigno/NPR

Honeybees crawl through a modern-day hive. This past winter saw the most dramatic losses of managed honeybee colonies in 13 years, according to researchers. Olivia Falcigno/NPR

"Beekeepers are trying their best to keep [mites] in check, but it's really an arms race," says Nathalie Steinhauer, science coordinator for the Bee Informed Partnership and co-author of the report (vanEngelsdorp is also an author). "That's concerning, because we know arms races don't usually end well."

Steinhauer says Varroa mites are the "number one concern" around wintertime. They've become harder to control, she says, because some of the tools that beekeepers have been using — chemical strips that attract and kill mites, essential oils and organic acids — are losing their efficacy.

Pollinators are responsible for one of every three bites of food we take, according to the U.S. Agriculture Department. Most of these pollinators are domesticated honeybees. They have become essential for many flowering crops, including blueberries, almonds and cherries. Wild insects can't be relied on to pollinate hundreds of acres of these crops, so fruit and nut producers call in commercial honeybee colonies instead.

Beekeepers use this device, called a smoker, to calm honeybees.  Olivia Falcigno/NPR

Beekeepers use this device, called a smoker, to calm honeybees. Olivia Falcigno/NPR

Beekeeping has thus become an essential cog in the machine of American industrial farming. But it's a tough industry. Commercial beekeepers are so migratory that it's difficult to track how many live in each state, and all that moving around is expensive and stressful. Beekeepers have to monitor thousands of hives for sickness and pests.

These winter losses have made business even tougher, says vanEngelsdorp.

"We're not worried about honeybees going extinct. What we're worried about is commercial beekeepers going extinct," he says. When hives die, beekeepers can split healthy hives to replace their numbers — but it's costly to do so. "The question is, how long can they do that and stay economically viable?"

If the beekeeping industry shrinks, he says, crop production will suffer. "If we want to continue to have a food supply that has the variety that we want, we need a movable pollination supply, and those are honeybees," he says. "If we don't have commercial beekeepers managing those, then we won't be able to meet that demand."

Dennis vanEngelsdorp pulls out a frame from a hive. Managed honeybee hives are usually made of stackable, separable components so that beekeepers can closely monitor the colony's health.  Olivia Falcigno/NPR

Dennis vanEngelsdorp pulls out a frame from a hive. Managed honeybee hives are usually made of stackable, separable components so that beekeepers can closely monitor the colony's health. Olivia Falcigno/NPR

Maryann Frazier, a retired senior extension associate for the College of Agricultural Sciences at Pennsylvania State University, who was not involved with the survey, says its results are limited by the fact that they rely on self-reported data from beekeepers. Beekeepers who've lost a lot of bees may be more likely to contribute to the survey, she says.

Still, she says the results are troubling, if unsurprising. Stressed, sick bees in close proximity are likely to die during the winter months. And bees face increasing levels of stress. Until all parties work together to address the sources of that stress, she says, steep winter die-offs will continue.

"I don't expect to see a change in losses over time for this reason. There's been no significant effort to correct what's causing the decline," she says.

Take pesticides, she says. "There's a huge amount of data [and] research showing pesticides are a significant player in the decline of honeybees and other insect species. And yet there's been so little done to make a change on that front," she says. "The EPA has been incredibly ineffective."

She says that pesticide industry leaders often try to shift blame for bee declines solely onto Varroa mites and viruses when in fact, she says, "there is so much evidence that pesticides are a major player in the decline of honeybees."

"And these things are synergistic," she adds. Pesticides can compromise immune systems, so when a mite or other pest hits "a bee compromised by pesticides, it's a downward spiral." Other sources of stress, like changing landscapes, have not been corrected.

Bees crawl over larvae and capped honey cells on a hive frame. Larvae are especially vulnerable to pests like  Varroa  mites.  Olivia Falcigno/NPR

Bees crawl over larvae and capped honey cells on a hive frame. Larvae are especially vulnerable to pests like Varroa mites. Olivia Falcigno/NPR

Honeybees are a "sentinel species," Frazier says, meaning that their losses may warn humans of the larger trend of insect decline worldwide, including the decline of other pollinators like beetles and wild bees. "The picture is well beyond honeybees," she says. "The whole system is crashing."

https://www.npr.org/sections/thesalt/2019/06/19/733761393/more-bad-buzz-for-bees-record-numbers-of-honey-bee-colonies-died-last-winter

[NOTE: The beekeepers in this story are working the bees in short sleeves and without protective clothing. They are located in the state of Maryland. They do not have the danger of Africanized Honey Bees. If you are in areas such as Southern California, which have AHB, we advise that you DO NOT work your bees without protective clothing.]