2016 Ontario Apiculture Winter Loss Survey

Table of Contents


Introduction

In recent years, managed honey bee colonies have experienced high losses across many jurisdictions in both Canada and the United States. During the period of 2005 to 2015, the average estimated overwinter honey bee mortality was 31.5 per cent. In Ontario, winter loss peaked at 58 per cent during the winter of 2013-2014 and was estimated to be 38 per cent following the winter of 2014-2015. Recently, honey bee losses during the 2015-2016 winter were estimated to be 18 per cent.

It is important to note that 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 number 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, 2015, Ontario beekeepers registered 88,950 colonies for the 2016 beekeeping season (compared to 100,200 registered colonies in the previous year). This represents the number of registered colonies that were alive going into winter of 2015-2016.

Methodology

During the spring of 2016, OMAFRA's Apiary Program surveyed Ontario beekeepers to estimate honey bee colony losses over the winter of 2015-2016. The Canadian Association of Professional Apiculturists (CAPA) National Winter Loss Survey Committee establishes a core set of questions for inclusion in each provincial survey to improve the consistency and comparability of honey bee health across the country. The Ontario Apiary Program shares this standardized information with CAPA in an aggregated format. 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.

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 Ontario winter loss percentage is calculated using responses from commercial beekeepers only. However, this Ontario report includes responses provided by all beekeepers, both commercial and small-scale, collected through the 2016 Ontario Apiculture Winter Loss Survey. For the purpose of this report, commercial and small-scale beekeepers are viewed as two separate populations. The survey seeks the thoughts, impressions and opinions of Ontario's beekeepers and the information provided is voluntarily self-reported. The responses to this survey provided by beekeepers, such as the number of colonies that died during the winter, have not been verified by OMAFRA or any other independent body.

Using the number of colonies reported by beekeepers, the provincial overall winter loss is calculated using the following formula:

Winter loss (%) = ((total # of reported dead and nonviable colonies as of May 15,2016)/(total # of reported live colonies at the start of winter 2015))x 100

A dead colony is no longer commercially viable. A commercially viable colony is defined as having four frames or more being 75 per cent bee-covered on both sides in a standard 10-frame hive. This definition was harmonized by CAPA in 2015 to ensure that all provinces report in the same manner. Ontario has used the CAPA definition since 2010.

Data from commercial and small-scale beekeepers were analyzed separately. The survey was distributed to 203 registered commercial beekeepers (defined for this purpose as having 50 colonies or greater) and 400 randomly selected small-scale beekeepers (defined for this purpose as having 49 colonies or fewer). Beekeepers had the option of responding electronically via online survey, by submitting a completed hard-copy or by phone. Responses were received from 146 commercial beekeepers and 174 small-scale beekeepers which represents 53 per cent of beekeepers who received the survey.

By beekeeper type, responses were received from 72 per cent of commercial beekeepers representing 67,250 colonies and 44 per cent of small-scale beekeepers representing 1,884 colonies (Table 1). Combined, the responses represent 78 per cent of the total number of colonies registered in Ontario as of December 31, 2015. 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.

Table 1. Number of commercial and small-scale beekeepers, by region, responding to the 2016 Ontario Apiculture Winter Loss Survey.

Region Commercial Beekeepers1 Small-scale Beekeepers2
# of Respondents % of Respondents # of Respondents % of Respondents
Central
61 41.8 49 28.2
East
29 19.9 45 25.7
North
4 2.7 21 12.1
South
37 25.3 48 27.6
Southwest
15

10.3

11 6.3
Total
146 100 174 100

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

Results

The information in this report is a summary of the responses gathered from beekeepers who responded to the winter loss survey.

Honey Bee Colony Winter Loss

Ontario commercial beekeepers reported an estimated 18 per cent overall honey bee colony loss during the 2015-2016 winter (Table 2).

Table 2. The number of full sized honey bee colonies put into winter in the fall of 2015, the number of viable over-wintered colonies and the number of non-viable colonies as of May 15th, 2016 based on beekeeper responses to the 2016 Ontario Apiculture Winter Loss Survey.

Beekeeper Type Full sized colonies wintered in Fall 2015 Viable over-wintered colonies as of May 15th, 2016 Non-viable colonies as of May 15th, 2016 Winter Loss (%)
Commercial1
67,250 55,195 12,055 17.9
Small-scale2
1,884 1,435 449 23.8

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

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 2015).

The beekeeping industry has been divided into five distinct regions by provincial county based on geography, climate and weather patterns (Fig. 1).

Beekeeping regions of Ontario

Figure 1. Beekeeping regions of Ontario: North (green), East (red), Central (yellow), South (blue) and Southwest (orange).

North: Manitoulin, Parry Sound, Nipissing, Sudbury, Algoma, Temiskaming, Cochrane, Thunder Bay, Rainy River, and Kenora counties.

East: Hastings, Renfrew, Lennox & Addington, Prince Edward, Frontenac, Leeds & Grenville, Lanark, Ottawa, Stormont, Dundas & Glengarry, and Prescott & Russell counties.

Central: Muskoka, Bruce, Grey, Simcoe, Peel, York, Toronto, Durham, Dufferin, Kawartha Lakes, Haliburton, Peterborough, and Northumberland counties.

South: Wellington, Huron, Perth, Oxford, Norfolk, Brant, Waterloo, Hamilton, Halton, Haldimand, and Niagara counties.

Southwest: Middlesex, Elgin, Lambton, Chatham-Kent, and Essex counties.

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. Small-scale beekeeping operations had a similar response rate (ranging from 45 - 49 respondents) from the central, east and south beekeeping regions.

The estimated winter losses and the number of respondents varied by region (Table 3). Commercial beekeepers reported the greatest losses in the eastern region while small-scale beekeepers reported the highest losses in the south and eastern region. Overall, colony losses during the 2015-2016 winter differed by approximately 6 per cent between commercial and small-scale beekeepers. The ministry has been tracking overwinter losses of commercial beekeepers for several years. We began tracking those reported by small-scale beekeepers in 2014, making it possible to compare the two groups. Since 2014, this is the first occurrence of a difference between the overwinter losses estimated for commercial and small-scale beekeeping groups.

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

Beekeeping Region Commercial Beekeepers1 Small-scale Beekeepers2
# of Respondents Overall Winter Loss (%) # of Respondents Overall Winter Loss (%)
Central
61 18.3 49 20.3
East
29 26.3 45 26.2
North
4 20.6 21 21.0
South
37 15.9 48 27.4
Southwest
15 16.5 11 20.8
Total
146 17.9 174 23.8

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

When beekeepers were grouped by operation size (number of colonies managed) the honey bee colony loss during the 2015-2016 winter was similar among most groups (Table 4) with the exception of beekeepers operating fewer than 10 colonies and operations of 501 to 1000 colonies. Beekeepers operating 501 to 1000 colonies reported fewer honey bee colony losses than other beekeepers (9.7 per cent). However, the number of respondents in this category was low (sample size of eight) 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 (Table 4) and these operations reported the greatest overwinter honey bee colony losses.

Table 4. Overwinter honey bee colony losses during the winter of 2015-2016 by size of beekeeping operation (number of colonies operated).

# of Respondents # of Colonies Reported in the Fall of 2015 Average Winter Loss (%)
115 <102 31.1
59 10-492 20.7
85 50-2001 21.2
37 201-5001 20.4
8 501-10001 9.7
16 >10001 17.7

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

Beekeepers were asked to report on what they believed were the main attributing factors for their colony loss during the winter of 2015-2016. These opinions may have been based on symptoms, beekeeper experience and judgment, or speculation. Starvation, poor queens and weak colonies in the fall were the most commonly reported factors influencing winter losses by both commercial and small-scale beekeepers (Table 5).

Table 5. The number of commercial and small-scale beekeepers reporting contributing factors to honey bee colony losses during the winter of 2015-2016.

Suspected Cause of Colony Loss # of Commercial1 Beekeepers Reporting # of Small-Scale2 Beekeepers Reporting
Starvation
57 25
Poor queens
66 34
Weather
20 21
Ineffective Varroa control
28 15
Nosema
10 6
Weak colonies in the fall
56 45
Other3
31 21
Don't know
37 52

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

3When respondents selected "Other", the most commonly reported factors were suspected pesticide damage (responses from 15 commercial and 10 small-scale beekeepers) and wildlife damage (responses from 4 commercial and 3 small-scale beekeepers)

Management Practices for Pests and Diseases

There are many theories for the increase in honey bee colony mortality in recent years and a number of factors that contribute to colony health. Colonies may be weakened or killed by pests and/or diseases, such as infestation by varroa mites. Management practices, including small cluster size and inadequate food stores, 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 control of the beekeeper, monitoring for and the treatment of pests and diseases can be managed. For this reason, the 2016 winter loss survey focused on the surveillance, management and monitoring of three major threats to colony health: varroa, nosema and American foulbrood.

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 2015 beekeeping season (Table 6).

Type of varroa monitoring method used by commercial and small-scale beekeepers in 2015.

Figure 2. Type of varroa monitoring method used by commercial and small-scale beekeepers in 2015.

Text Equivalent to Figure 2

Of the beekeepers who responded to this question, 78 per cent of commercial beekeepers and 64 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. More information on the degree of varroa infestation observed in Ontario honey bee colonies can be found in the 2015 Provincial Apiarist Report, available online at www.ontario.ca/beekeeping.

Table 6. Treatments reported by commercial and small-scale beekeepers used to control varroa mites in the spring and fall of 2015.

Varroa Treatment Spring 2015 Fall 2015
Commercial1 Beekeepers Small-scale2 Beekeepers Commercial Beekeepers Small-scale Beekeepers
Apistan® (fluvalinate)
7 14 11 16
CheckMite+™ (coumaphos)
0 0 1 4
Apivar® (amitraz)
37 14 66 37
Thymovar (thymol)
2 9 6 14
65% formic acid (40 ml multiple application)
43 16 41 11
65% formic acid (250 ml single application)
13 20 13 19
Mite Away Quick Strips (formic acid)
21 30 26 32
Oxalic acid
7 6 40 24
Other3
7 9 3 7
None
31 61 7 30

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

3When respondents selected "Other", the most commonly reported factors were interrupting brood cycle and drone comb removal

Ontario beekeepers use a variety of options to manage varroa mites. In spring and fall 2015, the two most common methods of varroa mite treatment reported by commercial beekeepers were Apivar® and 65% liquid formic acid (40 ml multiple application), which is consistent with the results of the 2014-2015 survey. To date, there have been no documented cases of Apivar®-resistant varroa mites in Ontario.

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

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. To date, a relationship between nosema infection and colony loss during the winter months has not been identified (Guzman et al. 2010).

The majority of Ontario beekeepers did not treat for nosema during 2015 (Table 7). Seventy eight per cent of beekeepers who responded to this survey question indicated that nosema treatment was not applied in the spring and 75 per cent of respondents did not treat for the disease in the fall of 2015.

Table 7. Treatments reported by commercial and small-scale beekeepers used to control nosema in the spring and fall of 2015.

Nosema Treatment Spring 2015 Fall 2015
Commercial1 Beekeepers Small-scale2 Beekeepers Commercial beekeepers Small-scale Beekeepers
Fumagillin
21 41 31 40
Other
4 2 4 1
None
116 120 105 121

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

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 Ontario beekeepers who responded to this survey question treated for AFB during 2015 and the most common treatment reported was oxytetracycline (ranging from 57 per cent in the spring to 55 per cent 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 2015.

American Foulbrood Treatment Spring 2015 Fall 2015
Commercial1 Beekeepers Small-scale2 Beekeepers Commercial Beekeepers Small-scale Beekeepers
Oxytetracycline
102 64 94 66
Tylosin
2 0 2 1
Other
3 3 4 1
None
35 97 40 98

1Commercial beekeepers reporting 50 or greater colonies in the fall of 2015

2Small-scale beekeepers reporting 49 or fewer colonies in the fall of 2015

General Comments and Discussion

The Ontario Apiculture Winter Loss Survey is a valuable tool for gathering information on colony mortality, the type of management practices utilized and the concerns of Ontario beekeepers. This survey alone cannot paint a complete picture of honey bee health. For a comprehensive understanding of the state of honey bee health in Ontario, the results of this survey must be evaluated with data gathered in the field, in-season inspection reports, and monitoring projects. We know bee health is a complex issue and that is why the government's Pollinator Health Action Plan focuses on strengthening pollinator health to ensure healthy ecosystems, a productive agricultural sector and a strong economy.

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 2015). During the 2013-2014 winter, Ontario beekeepers reported the highest ever honey bee colony winter loss. For the past two winters, (2014-2015 and 2015-2016), the estimated overwinter colony loss has been in decline. Although this is good news for the industry, caution is indicated as overwinter losses vary from year to year and must be studied over a period of time before drawing conclusions.

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

The strategy for improving honey bee health in Ontario requires a comprehensive approach that addresses all of the above stress factors and includes the continued implementation of integrated pest management practices by beekeepers and crop growers, an increase in pollinator-friendly forage areas and additional research on honey bee health.

Since 2015, Ontario beekeepers have had access to a production insurance plan that will help beekeepers 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. For more information on the Bee Mortality Production Insurance Plan, please visit www.agricorp.com.

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.

References

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

Currie R., Guzman E. and Pernal, S. 2010. Honey bee colony losses in Canada. Journal of Apicultural Research. 49 (1): 104-106.

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.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: Wael Haddad - OMAFRA / Apiary Data Coordinator
Creation Date: 25 July 2016
Last Reviewed: 13 December 2016