2017 Ontario Apiculture Winter Loss Survey

Table of Contents


Introduction

Ontario's beekeeping industry is one of the most diverse in Canada. Ontario beekeepers are involved in honey production for a large domestic market, the production and sales of queens and nucleus colonies to satisfy an ever increasing demand for honey bees, in addition to providing bees to the fruit and vegetable sector for pollination.

In recent years, managed honey bee colonies have experienced variable overwinter mortality across many jurisdictions in both Canada and the United States. Since 2010, overwinter honey bee mortality in Ontario has been estimated to be as low as 12 per cent during the winter of 2011-2012 and peaked at 58 per cent during the winter of 2013-2014. During the winter of 2015-2016, overwinter mortality in Ontario was estimated to be 18 per cent followed by 27 per cent this year.

The beekeeping industry in Ontario is not static. The number of colonies and the amount of honey produced varies from year to year and is influenced by weather, management practices, pests, diseases and environmental stressors. The number of colonies operated by beekeepers also fluctuates throughout the year. After a decrease in colony numbers over the winter months, a beekeeper can build colony numbers during the summer months by splitting larger, healthy colonies into smaller nucleus colonies. As of December 31, 2016, Ontario beekeepers had registered 97,342 colonies which represents the number of registered colonies that were alive going into winter of 2016-2017.

Methodology

The Canadian Association of Professional Apiculturists (CAPA) National Winter Loss Survey Committee establishes the core questions which are asked by the provinces each year to estimate honey bee colony mortality during the winter. The CAPA coordinates how the overall winter loss is reported to ensure consistency across the provinces and survey years. For the purpose of the CAPA national report, the overwinter mortality in Ontario is calculated using responses from commercial beekeepers, those operating 50 or more colonies. Since 2007, CAPA has compiled data provided by each province, published an annual report on national honey bee colony losses, and provided an ongoing picture of the general health of apiculture in Canada.

During the spring of 2017, OMAFRA's Apiary Program surveyed Ontario beekeepers to estimate honey bee colony mortality during the winter of 2016-2017. The survey was distributed to 179 registered commercial beekeepers (defined as operating 50 colonies or greater) and 400 randomly selected small-scale beekeepers (defined as operating 49 colonies or fewer). Beekeepers had the option of responding electronically via online survey, by submitting a completed hard-copy or by phone. The survey responses represent a convenience sample, and the information provided is self-reported and voluntary. The responses to this survey provided by beekeepers, such as the number of colonies that died during the winter, are self-reported by beekeepers and have not been verified by OMAFRA or any other independent body.

Table 1. Number of commercial and small-scale beekeepers, by region, responding to the 2017 Ontario Apiculture Winter Loss Survey.

Region Commercial Beekeepers Small-scale Beekeepers
# of Respondents % of Respondents # of Respondents % of Respondents
Central
40 40.8 46 34.6
East
13 13.3 37 27.8
North
5 5.1 12 9.0
South
29 29.6 29 21.8
Southwest
11

11.2

9 6.8
Total
98 100 133 100

Table 2. The number of full sized honey bee colonies put into winter in the fall of 2016, the number of viable over-wintered colonies and the number of non-viable colonies as of May 15th, 2017 based on beekeeper responses to the 2017 Ontario Apiculture Winter Loss Survey.

Beekeeper Type Full sized colonies overwintered in Fall 2016 Viable overwintered colonies as of May 15th, 2017 Non-viable colonies as of May 15th, 2017 Overwinter Mortality (%)
Commercial
44,183 32,294 11,889 27
Small-scale
1,098 777 321 29

Using the number of colonies reported by beekeepers (Table 2), the provincial overwinter mortality is calculated using the following formula:

Overwinter Mortality (%) = (total # of reported dead & nonviable colonies as of May 15, 2017 ÷ total # of reported live colonies at the start of winter 2016) x 100

For the purpose of this survey, a honey bee colony is defined as a full-sized honey bee colony either in a single or double brood chamber, not including nucleus colonies (splits). A commercially viable colony is defined by CAPA as a colony which survived the winter and has a minimum of four frames with 75 per cent of the comb area covered with bees on both sides in a standard 10-frame hive. Dead colonies are included in the count of non-viable colonies.

This report includes responses provided by all beekeepers, both commercial and small-scale, collected through the 2017 Ontario Apiculture Winter Loss Survey. Data from commercial and small-scale beekeepers in Ontario were analyzed separately. Responses were received from 98 commercial beekeepers and 133 small-scale beekeepers which represents 40 per cent of beekeepers who received the survey.

By beekeeper type, responses were received from 55 per cent of commercial beekeepers representing 44,183 colonies and 33 per cent of small-scale beekeepers representing 1,098 colonies (Table 1). Combined, the responses represent 46.5 per cent of the total number of colonies registered in Ontario as of December 31, 2016. Although not reported to CAPA for inclusion in the national report on overwinter honey bee losses, responses from small-scale beekeeping operations will provide further insight into Ontario's beekeeping industry.

Results

Overwinter Honey Bee Colony Mortality

The information in this report is a summary of the responses gathered from beekeepers who responded to the winter loss survey. This information has not been verified by OMAFRA or any other independent body. Registered commercial and small-scale beekeepers in Ontario reported an approximate 27 per cent and 29 per cent overwinter mortality, respectively, during the winter of 2016-2017 (Table 2). In Canada, 15 per cent is the maximum level of overwinter losses considered to be acceptable and sustainable by the industry (Furgala and McCutcheon, 1992; CAPA, 2007 to 2016).

The beekeeping industry has been divided into five distinct regions based on geography, climate and weather patterns (Fig. 1). The survey was sent to beekeepers across the province and responses were received from all five beekeeping regions. Some beekeeping regions have greater beekeeping activity than others as shown when comparing the number of beekeepers in the Northern versus the Southern part of the province. The majority of commercial beekeepers who responded to the survey were from the Central and South beekeeping regions. These areas are known to have the greatest beekeeping activity. Responses from small-scale beekeeping operations were primarily from the Central, East and South beekeeping regions.

Ontario beekeeping regions: North (brown), East (orange), Central (yellow), South (red) and Southwest (green)

Figure 1. Ontario beekeeping regions: North (brown), East (orange), Central (yellow), South (red) and Southwest (green).

Text Equivalent to Figure 1

The estimated overwinter honey bee mortality and the number of respondents varied by beekeeping region (Table 3). Commercial beekeepers reported the greatest losses in the south region while small-scale beekeepers reported the highest losses in the eastern region. Overall, mortality during the 2016-2017 winter differed by approximately 2 per cent between commercial and small-scale beekeepers.

Table 3. Number of commercial and small-scale beekeeper survey respondents and the overwinter mortality (per cent) in 2017 for each beekeeping region in Ontario.

Beekeeping Region Commercial Beekeepers Small-scale Beekeepers
# of Respondents Overwinter Mortality (%) # of Respondents Overwinter Mortality (%)
Central
38 19 46 29
East
10 26 37 40
North
4 12 12 22
South
29 33 29 25
Southwest
11 20 9 18
Total
92* 27 133 29

*Responses were not received from 2 respondents from the central region, 3 from the east region and one from the north region.

When beekeepers were grouped by operation size (number of colonies managed) the honey bee mortality during the winter of 2016-2017 ranged from 15.4 to 35.1 per cent (Table 4). Beekeepers operating 501 to 1000 colonies reported fewer honey bee colony losses than other beekeepers (15.4 per cent).

Similar to previous years, the number of respondents in the 501 to 1000 colonies category was low and this apparent reduction in mortality among this group could be due to the small sample size. The greatest number of survey respondents had beekeeping operations with fewer than 10 colonies. As in previous years, operations with fewer than 10 colonies reported the greatest overwinter honey bee mortality (35 per cent). This group may be comprised of new beekeepers and persons who keep bees as a hobby. Therefore, this group may not have as much experience as commercial beekeepers which could contribute to the increased overwinter mortality.

Table 4. Overwinter honey bee mortality during the winter of 2016-2017 by size of beekeeping operation (number of colonies operated).

# of Respondents # of Colonies Reported in the Fall of 2016 Average Overwinter Mortality (%)
97 <10 35.1
35 10-49 26.8
56 50-200 29.2
19 201-500 22.5
6 501-1000 15.4
9 >1000 29.1

Beekeepers were asked to report what they believed were the main factors contributing to overwinter honey bee mortality. These opinions may be based on observable symptoms, beekeeper experience and judgment, or speculation. Poor queens, starvation and weak colonies in the fall were the most commonly reported factors influencing overwinter mortality by commercial beekeepers. Small-scale beekeepers however, reported that weather and weak colonies in the fall were the main factors contributing to overwinter mortality (Table 5).

Table 5. The number of commercial and small-scale beekeepers reporting contributing factors to honey bee colony mortality during the winter of 2016-2017.

Suspected Cause of Colony Loss # of Commercial Beekeepers Reporting # of Small-Scale Beekeepers Reporting
Starvation
33 21
Poor Queens
40 15
Weather
26 28
Ineffective Varroa control
30 23
Nosema
9 2
Weak Colonies in the Fall
32 26
Other
23 25
Don't know
23 20

Management Practices for Pests and Diseases

There are many theories which aim to explain the observation of increased overwinter honey bee mortality in recent years. The scientific literature suggests that honey bee health is complex and that there are many factors that contribute to honey bee colony health. For example, colonies may be weakened or killed by pests and/or diseases, such as infestation by the parasitic mite, Varroa destructor. Poor management practices, including small cluster size, inadequate food stores and inadequate control of varroa mites may contribute to winter losses. Other factors such as severe weather, habitat loss and exposure to pesticides are environmental stressors which may potentially contribute to colony health.

While some factors contributing to colony mortality such as severe weather are not within the direct control of the beekeeper, monitoring for and the treatment of pests and diseases can be controlled by the beekeeper. For this reason, the 2017 winter loss survey focused on the surveillance, management and monitoring of three major threats to colony health: varroa, nosema and American foulbrood.

Varroa mites (Varroa destructor)

Varroa mites are relatively large external parasites that feed on the body fluids of adult and developing honey bees. Varroa mites cause physical damage, weaken bees and transmit a variety of pathogens, particularly viruses. In almost all cases, when varroa infestations are not effectively managed, the death of the honey bee colony will follow. Beekeepers were asked how they monitored for varroa infestations (Fig. 2) and which treatments were used at the beginning (spring) and the end (fall) of the 2016 beekeeping season (Table 6).

Type of varroa monitoring method used by commercial and small-scale beekeepers in 2016

Figure 2. Type of varroa monitoring method used by commercial and small-scale beekeepers in 2016. Survey respondents could reply with more than one answer.

Text Equivalent to Figure 2

Of the beekeepers who responded to this question, 89 per cent of commercial beekeepers and 65 per cent of small-scale beekeepers advised that they monitor for varroa infestation in their colonies. Of those, a number of methods were used, the most common being either an alcohol wash or a sticky board. Some beekeepers used more than one method to monitor for varroa. Most commonly, when the response "other" was selected, the beekeeper reported that they visually check their colonies for varroa or use the sugar shake method which are not recommended methods for monitoring varroa.

Ontario beekeepers use a variety of options to manage varroa mites. In spring and fall of 2016, the most common method of varroa mite treatment reported by commercial beekeepers was Apivar®. Commercial beekeepers also reported using 65 per cent liquid formic acid (40 ml multiple application), mite away quick strips and Apistan®. Small-scale beekeepers indicated a preference for mite away quick strips over other forms of mite control options. Although there has been documented resistance to some mite control products such as Apistan® and Checkmite+™, there have been no documented cases of Apivar®-resistant varroa mites in Ontario to date.

The two least commonly used treatments by both commercial and small-scale beekeepers were Check- mite+™ and Thymovar. To slow the development of resistance to chemical treatments, Ontario beekeepers are advised to rotate varroa mite treatments as part of an integrated pest management (IPM) strategy.

Table 6. Treatments reported by commercial and small-scale beekeepers used to control varroa mites in the spring and fall of 2016. Survey respondents could respond with more than one answer.

Varroa Treatment Spring 2016 Fall 2016
Commercial1 Beekeepers (#) Small-scale2 Beekeepers (#) Commercial Beekeepers (#) Small-scale Beekeepers (#)
Apistan® (fluvalinate)
7 7 14 15
CheckMite+™ (coumaphos)
1 1 1 2
Apivar® (amitraz)
23 7 46 19
Thymovar (thymol)
1 3 3 3
65% formic acid (40 ml multiple application)
16 20 15 20
65% formic acid (250 ml single application)
4 6 6 3
Mite Away Quick Strips (formic acid)
13 26 21 36
Oxalic acid
6 5 30 19
Other
3 7 1 4
None
32 57 7 28

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2016

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2016

Nosema spp.

Nosema (N. ceranae and N. apis) is a fungal pathogen that infects the digestive system of honey bees. Nosema may be an added stress to honey bee colonies, depending on the time of year. A relationship between nosema infection and colony loss during the winter months has not been identified (Guzman et al. 2010; Emsen et al. 2016).

The majority of Ontario beekeepers did not treat for nosema during 2016 (Table 7). Seventy three per cent of beekeepers (both commercial and small-scale) who responded to this survey question indicated that nosema treatment was not applied in the spring and 71 per cent of respondents did not treat for the disease in the fall of 2016.

Table 7. Treatments reported by commercial and small-scale beekeepers used to control nosema in the spring and fall of 2016.

Nosema Treatment Spring 2016 Fall 2016
Commercial1 Beekeepers (#) Small-scale2 Beekeepers (#) Commercial beekeepers (#) Small-scale Beekeepers (#)
Fumagillin
16 35 21 34
Other
0 3 0 3
None
76 92 72 92

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2016

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2016

American Foulbrood (Paenibacillus larvae)

American foulbrood (AFB) is caused by a spore forming bacteria, Paenibacillus larvae. The clinical symptoms of diseased honey bee larvae can be visually identified in the field, while the spores are only visible under a high power microscope. Honey bee larvae can become infected by ingesting P. larvae spores present in their food. These spores germinate in the gut of the larva, and may eventually kill the infected larvae.

The majority of commercial beekeepers (78 per cent) who responded to this survey question treated for AFB during 2016 and the most common treatment reported was oxytetracycline (Table 8). Forty one per cent of small-scale beekeepers reported treating for AFB in the spring and 44 per cent of small-scale beekeepers used AFB treatments in the fall (Table 8). Although oxytetracycline-resistant AFB has been detected in other jurisdictions such as the USA, there have not been any documented cases of resistant forms in Ontario.

Table 8. Treatments reported by commercial and small-scale beekeepers used to control American foulbrood in the spring and fall of 2016.

American Foulbrood Treatment Spring 2016 Fall 2016
Commercial Beekeepers (#) Small-scale Beekeepers (#) Commercial Beekeepers (#) Small-scale Beekeepers (#)
Oxytetracycline
71 52 70 51
Tylosin
1 0 1 0
Other
1 1 2 1
None
22 79 23 75

General Comments and Discussion

The Ontario Apiculture Winter Loss Survey is a valuable tool for gathering information on colony mortality and the management practices used by beekeepers to monitor and control diseases. Honey bee colony mortality differs from year to year, among different beekeeping regions and individual beekeeping operations. This survey alone cannot paint a complete picture of honey bee health. Honey bee health is complex and it is difficult to attribute overwinter losses to a single cause. The main stress factors influencing declines in the number of pollinators in Ontario have been identified as:

  • extreme weather and climate change,
  • disease, pests and genetics,
  • reduced habitat and poor nutrition, and
  • exposure to pesticides

That's why Ontario's Pollinator Health Action Plan was developed to help address several of the key stressors on pollinator health. Implementation of the action plan is ongoing, and includes:

  • investing $1 million in innovative pollinator health research,
  • working to restore and protect one million acres of pollinator habitat across the province, and
  • developing and delivering a suite of activities and programs designed to enhance beekeeper knowledge of emerging issues and research, best management and integrated pest management practices.

Additionally, commercial beekeepers now have access to a production insurance plan to help them manage financial loss from overwinter bee colony damage. The Bee Mortality Production Insurance Plan gives participating beekeepers the confidence and security to reinvest in their operations, encouraging greater innovation, profitability and job creation and provides them with the same financial support that beekeepers in other provinces receive.

The government is working to strengthen the apiculture industry. The government is committed to working with farmers, beekeepers and other stakeholders to implement long-term, sustainable initiatives to improve the health of bees and other pollinators.

CAPA has compiled overwinter mortality data provided by each province and published an annual report on national honey bee colony losses since 2007. Ontario beekeepers have frequently reported overwinter mortality higher than the national average (Fig. 3).

Overwinter mortality (%) reported by beekeepers in Ontario and Canada with linear trends from 2006-2007 to present.

Figure 3. Overwinter mortality (%) reported by beekeepers in Ontario (blue) and Canada (grey) with linear trend lines from 2006-2007 to present. Note that the national overwinter mortality is not yet available for 2016-2017.

Text Equivalent to Figure 3

Since 2010, Ontario beekeepers have reported annual overwinter honey bee colony losses of 15 per cent or greater in all years except 2012 (12 per cent). In Canada, 15 per cent is the maximum of overwinter losses considered to be acceptable and sustainable by the apiculture industry (Furgala and McCutcheon, 1992; CAPA, 2007 to 2016). During the winter of 2013-2014, Ontario beekeepers reported a record 58 per cent overwinter mortality. In 2014-2015 and 2015-2016, the estimated overwinter mortality declined to 38 per cent and 18 per cent, respectively. This was followed by a 27 per cent overwinter mortality in 2016-2017. While Ontario beekeepers have reported overwinter mortality higher than the national average in recent years, colony losses are lower compared to reported losses for beekeepers in the United States. American beekeepers reported 40.5 per cent losses in 2015-2016 followed by 33 per cent overwinter mortality in 2016-2017 (Steinhauer et al. 2017).

For More Information

For more information about Ontario's Apiculture Industry, or to access resources and services available from the Ontario Ministry of Agriculture, Food and Rural Affairs' Apiary Program, including treatment recommendations and best management practices for biosecurity, high risk pests, diseases and overwintering, please visit www.ontario.ca/beekeeping.

To learn more about Ontario's commitment to Pollinator Health, including our government's actions to improve the health and reduce the loss of Ontario's wild pollinators and managed bees, please visit www.ontario.ca/pollinators.

For more information on the Bee Mortality Production Insurance Plan, please visit www.agricorp.com.

References

Canadian Association of Professional Apiculturists (CAPA) Statement on honey bee losses in Canada. 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 and 2016. www.capabees.com

Emsen, B., Guzman-Novoa, E., Hamiduzzaman, M., Eccles L., Lacey, B., Ruiz-Pérez, R., Nasr, M. 2016. Higher prevalence and levels of Nosema ceranae than Nosema apis infections in Canadian honey bee colonies. Parasitology Research, 115:175-181

Furgala B. and McCutcheon, D.M. 1992. Wintering productive colonies. In Graham J M (Ed). The hive and the honey bee (revised edition). Dadant and Sons; Hamilton, IL, USA pp. 829-868

Guzman-Novoa, E., Eccles L., Calvete, Y., McGowan, J., Kelly, P. and Correa-Benitez, A. 2010. Varroa destructor is the main culprit for death and reduced populations of overwintered honey bees in Ontario, Canada. Apidologie, 4 (4) 443-451

Steinhauer, a. Rennich, K. Caron, D.M. Ellis, J.D. et al. 2017. Honey Bee Colony Losses 2016-2017: Preliminary Results. The Bee Informed Partnership. beeinformed.org


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: Marcia Chiasson - OMAFRA /Issues Coordinator
Creation Date: 17 August 2017
Last Reviewed: 17 August 2017