Honey bee colony losses in the US have exceeded acceptable levels for at least a decade, leaving beekeepers in need of management practices to improve colony health and survival. Here, an empirical ...Best Management Practice (BMP) regimen was tested, comprised of the top four management practices associated with reduced colony mortality in backyard beekeeping operations according to Bee Informed Partnership Loss and Management survey results. Seven study locations were established across the US, and each location consisted of ten colonies treated according to empirical BMPs and ten according to average beekeeping practice. After 3 years, colonies treated according to empirical BMPs experienced reduced Varroa infestation, viral infection, and mortality compared to colonies managed with Average practices. In addition, BMP colonies produced more new colonies via splits. The colonies under Average practices were given chemical Varroa treatments only once per year, and thus spent more months above economic threshold of 3.0 mites/100 bees. Increased time spent above the economic threshold was significantly correlated to both increased viral infection and colony mortality. This study demonstrates the cumulative effects of management and colony health stressors over months and years, especially the dire importance of regular Varroa monitoring and management.
A metagenomic analysis of the virome of honey bees (
) from an apiary with high rates of unexplained colony losses identified a novel RNA virus. The virus, which was named
solinvivirus 1 (AmSV1), ...contains a 10.6 kb positive-strand genomic RNA with a single ORF coding for a polyprotein with the protease, helicase, and RNA-dependent RNA polymerase domains, as well as a single jelly-roll structural protein domain, showing highest similarity with viruses in the family
. The injection of honey bee pupae with AmSV1 preparation showed an increase in virus titer and the accumulation of the negative-strand of AmSV1 RNA 3 days after injection, indicating the replication of AmSV1. In the infected worker bees, AmSV1 was present in heads, thoraxes, and abdomens, indicating that this virus causes systemic infection. An analysis of the geographic and historic distribution of AmSV1, using over 900 apiary samples collected across the United States, showed AmSV1 presence since at least 2010. In the year 2021, AmSV1 was detected in 10.45% of apiaries (95%CI: 8.41-12.79%), mostly sampled in June and July in Northwestern and Northeastern United States. The diagnostic methods and information on the AmSV1 distribution will be used to investigate the connection of AmSV1 to honey bee colony losses.
This study records the fifth consecutive year that winter losses of managed honey bee (Apis mellifera) colonies in the USA have been around 30%. In April 2011, a total of 5,441 US beekeepers (an ...estimated 11% of total US beekeepers) responded to a survey conducted by the Bee Informed Partnership. Survey respondents reported that they had lost an average of 38.4% of their colonies, for a total US colony loss of 29.9% over the winter of 2010-11. One-third of respondents (all classified as backyard beekeepers, i.e. keeping fewer than 50 colonies) reported no winter loss. There was considerable variation in both the average and total loss by state. On average, beekeepers consider acceptable losses to be 13.2%, but 68% of all responding beekeepers suffered actual losses in excess of what they considered acceptable. Of beekeepers who reported losing at least one colony, manageable conditions, such as starvation and a weak condition in the fall, were the leading self-identified causes of mortality. Respondents who indicated that varroa mites (Varroa destructor), small hive beetles (Aethina tumida), poor wintering conditions, and/or Colony Collapse Disorder (CCD) conditions were a leading cause of mortality in their operations suffered a higher average loss than beekeepers who did not list any of these as potential causes. In a separate question, beekeepers who reported the symptom "no dead bees in hive or apiary" had significantly higher losses than those who did not report this symptom. In addition, commercial beekeepers were significantly more likely to indicate that colonies died with this symptom than either backyard or sideliner beekeepers.
For the past six years in which overwintering mortality of honey bee colonies has been surveyed in the USA, estimates of colony loss have fluctuated around one-third of the national population. Here ...we report on the losses for the 2012-2013 seasons. We collected data from 6,482 US beekeepers (6,114 backyard, 233 sideline, and 135 commercial beekeepers) to document overwintering mortality rates of honey bee colonies for the USA. Responding beekeepers reported a total 30.6% (95% CI: 30.16-31.13%) loss of US colonies over the winter, with each beekeeper losing on average 44.8% (95% CI: 43.88-45.66%) of their colonies. Total winter losses varied across states (range: 11.0% to 54.7%). The self-reported level of acceptable winter loss was 14.6%, and 73.2% of the respondents had mortality rates greater than this level. The leading self-identified causes of overwintering mortality were different according to the operation type; backyard beekeepers generally self-identified "manageable" factors (e.g., starvation, weak colony in the fall), while commercial beekeepers generally identified non-manageable factors (e.g., queen failure, pesticides) as the main cause of losses. For the first time in this series of surveys, we estimated mortality during the summer (total loss = 25.3% (95% CI: 24.80-25.74%), average loss = 12.5% (95% CI: 11.92-13.06%)). The entire 12-months period between April 2012 and April 2013 yielded a total loss of 45.2% (95% CI: 44.58-45.75%), and an average loss of 49.4% (95% CI: 48.46-50.43%). While we found that commercial beekeepers lost fewer colonies than backyard beekeepers in the winter (30.2% (95% CI: 26.54-33.93% vs 45.4% (44.46-46.32%) respectively), the situation was reversed in the summer where commercial beekeepers reported higher average losses than backyard beekeepers (21.6% (95% CI: 18.4-24.79%) vs 12.1% (11.46-12.65%)). These findings demonstrate the ongoing difficulties of US beekeepers in maintaining overall colony heath and survival.
Little is known about the economics of small-scale beekeeping, due in part because many of these beekeepers are motivated by personal enjoyment and not profit. These beekeepers, however, represent ...more than 90% of US beekeeping population, so economic analysis of this majority group is warranted. Understanding how management practices impact colony profitability in small apiaries can inform beekeeper management decisions. Best management practices (BMPs) can increase colony productivity and survival, but often require additional labor and materials compared to less intensive beekeeping practices. Here, we investigate the impact of BMPs on the profitability of small-scale beekeeping. We found that BMPs required higher costs in labor and materials, but that they also produced higher revenue from honey and nucleus colony production. As a result, after three years, BMP apiaries were 8 times more profitable than less intensively managed apiaries. The increased profitability in BMP apiaries is largely attributed to improved colony health and survival due to more active Varroa management and reduced Varroa and viral loads. These results can inform small scale beekeeper budgeting and management, and also support extension efforts to increase BMP adoption.
Beekeepers in the United States have experienced high losses of managed honey bee (Apis mellifera) colonies for more than a decade. Long-term, multi-year monitoring efforts are crucial to provide a ...temporal and spatial context to these losses. To document and explain these losses, the Bee Informed Partnership has conducted national surveys on managed honey bee colonies since spring 2011, continuing the work of surveys first commissioned by the Apiary Inspectors of America in spring 2007. Here we present survey results from three years - 2017-18, 2018-19, and 2019-20. Each year, colony loss rates were estimated and compared among three loss periods - summer, winter, and annual - and three beekeeping operation types based on their number of colonies managed - backyard (≤50 colonies), sideline (51-500 colonies), and commercial (>500 colonies). At the national level, we recorded the highest winter colony loss rates (37.7%) in 2018-2019, while 2019 marked the year with the highest summer losses (32.1%). As documented in past surveys, we observed that smaller scale backyard beekeepers experienced the highest winter loss rates when compared to the larger operation types. Similarly, commercial beekeepers experienced higher loss rates during the summer compared to the other operation types. Overall, our results highlight the temporal variability, specifically among loss periods and years, of colony loss rates in the United States, and suggest a strong effect of beekeeping operation size.
Honey bees Apis mellifera forage in a wide radius around their colony, bringing back contaminated food resources that can function as terrestrial bioindicators of environmental pesticide exposure. ...Evaluating pesticide exposure risk to pollinators is an ongoing problem. Here we apply five metrics for pesticide exposure risk (prevalence, diversity, concentration, significant pesticide prevalence, and hazard quotient (HQ)) to a nation-wide field study of honey bees, Apis mellifera in the United States. We examined samples from 1055 apiaries over seven years for 218 different pesticide residues and metabolites, determining that bees were exposed to 120 different pesticide products with a mean of 2.78 per sample. Pesticides in pollen were highly prevalent and variable across states. While pesticide diversity increased over time, most detections occurred at levels predicted to be of low risk to colonies. Varroacides contributed most to concentration, followed by fungicides, while insecticides contributed most to diversity above a toxicity threshold. High risk samples contained one of 12 different insecticides or varroacides. Exposures predicted to be low-risk were nevertheless associated with colony morbidity, and low-level fungicide exposures were tied to queen loss, Nosema infection, and brood diseases.
Display omitted
•A US national survey of pesticide residues in bee pollen found only 18% of samples were pesticide free. .•In our 1055 samples we made 2933 pesticide detections, predominantly at low risk levels. .•However, some low risk residues like fungicides were linked to increased colony morbidity. .•Neonicotinoids were rarely detected (2.0%), but contributed significant risk when found. .
The US National Honey Bee Disease Survey sampled colony pests and diseases from 2009 to 2014. We verified the absence of
Tropilaelaps
spp., the Asian honey bee (
Apis cerana
), and slow bee paralysis ...virus. Endemic health threats were quantified, including
Varroa destructor
,
Nosema
spp., and eight honey bee viruses.
Varroa
loads varied across years, with annual fall peaks;
Nosema
peaked January to April. Migratory beekeepers had significantly lower
Varroa
prevalence (84.9 vs. 97.0 %) and loads (3.65 ± 0.28 vs. 5.99 ± 0.22) than stationary operations, while
Nosema
was more prevalent (59.9 vs. 46.7 %) in migratory colonies. Since 2010, chronic bee paralysis virus prevalence doubled annually. We detected strong positive relationships between
V. destructor
and
Varroa
-transmitted viruses, between
Nosema
and Lake Sinai virus 2, and a positive relationship across several viral pathogens of bees. The results provide a disease baseline to help identify drivers of poor bee health.
Managed honey bee colony losses are of concern in the USA and globally. This survey, which documents the rate of colony loss in the USA during the 2015-2016 season, is the tenth report of winter ...losses, and the fifth of summer and annual losses. Our results summarize the responses of 5725 valid survey respondents, who collectively managed 427,652 colonies on 1 October 2015, an estimated 16.1% of all managed colonies in the USA. Responding beekeepers reported a total annual colony loss of 40.5% 95% CI 39.8-41.1% between 1 April 2015 and 1 April 2016. Total winter colony loss was 26.9% 95% CI 26.4-27.4% while total summer colony loss was 23.6% 95% CI 23.0-24.1%, making this the third consecutive year when summer losses have approximated to winter losses. Across all operation types, 32.3% of responding beekeepers reported no winter losses. Whilst the loss rate in the winter of 2015-2016 was amongst the lowest winter losses recorded over the ten years this survey has been conducted, 59.0% (n = 3378) of responding beekeepers had higher losses than they deemed acceptable.
Honey bee colony losses are a major concern in the USA and across the globe. Long-term data on losses are critical for putting yearly losses in context. US colony loss surveys have been conducted ...yearly since the winter of 2006–2007. Here, we report the results from the eighth annual survey on winter losses and the second annual survey of summer and annual losses. There were 7425 valid respondents (7123 backyard, 190 sideline, and 112 commercial beekeepers) managing 497,855 colonies, 19 % of the total US colonies. Total losses reported were 19.8 % 95 % CI 19.3–20.3 % over the summer, 23.7 % 95 % CI 23.3–24.1 % over the winter, and 34.1 % 95 % CI 33.6–34.6 % for the whole year. Average losses were 15.1 % 95 % CI 14.5–15.7 % over the summer, 44.8 % 95 % CI 43.9–45.7 % over the winter, and 51.1 % 95 % CI 50.2–51.6 % for the whole year. While total winter loss was one of the lowest reported in 8 years, 66 % of all beekeepers had higher losses than they deemed acceptable.
PDF
