2018 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 as well as the production and sale of queens and nucleus colonies to satisfy an ever increasing demand for honey bees for activities such as pollination services for the fruit and vegetable sector.

Over the 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 was estimated to be as low as 12 per cent during the winter of 2011-2012 and as high as 58 per cent during the winter of 2013-2014. During the previous winter of 2016-2017, overwinter mortality in Ontario was estimated to be 27 per cent followed by 46 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, 2017, Ontario beekeepers had registered 105,244 colonies which represents the number of registered colonies that were alive going into the winter of 2017-2018.

Methodology

The Canadian Association of Professional Apiculturists (CAPA) National Winter Loss Survey Committee establishes the core questions which are asked of the provinces each year to estimate honey bee colony mortality during the winter. 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 only. Since 2007, CAPA has compiled data provided by each province, published an annual report on national honey bee colony losses, and provides an ongoing picture of the general health of apiculture across Canada.

During the spring of 2018, the Ontario Ministry of Agriculture, Food and Rural Affairs' (OMAFRA) Apiary Program surveyed Ontario beekeepers to estimate honey bee colony mortality during the winter of 2017-2018. The survey was distributed to 186 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 an online survey, by submitting a completed hard-copy, or by phone. The survey is voluntary and the survey responses, such as the number of colonies that died during the winter, are self-reported by beekeepers and are not verified by OMAFRA or any other independent body.

Table 1. Number of beekeepers, by region, responding to the 2018 Ontario Apiculture Winter Loss Survey.

Beekeeping Regions
Commercial Beekeepers
Small-Scale Beekeepers
# of Respondents
% of Respondents
# of Respondents
% of Respondents
Central
41
35.0
29
24.6
East
23
19.7
36
30.5
North
5
4.3
17
14.4
South
36
30.8
27
22.9
Southwest
12
10.3
9
7.6
Total
117
63
118
30

Table 2. Overwinter Mortality for 2017-2018.

Beekeeper Type
# of Full-Sized Colonies put into Winter in Fall 2017
# of Viable Overwintered Colonies as of May 15, 2018
# of Non-viable colonies as of May 15th, 2018
Overwinter Mortality (%)
Commercial
63,236
34,327
28,909
45.7
Small-scale
1,287
702
585
45.5

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 & non-viable colonies as of May 15, 2018 ÷ total # of reported live colonies at the start of winter 2017) 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 considers all responses provided by beekeepers, both commercial and small-scale, collected through the 2018 Ontario Apiculture Winter Loss Survey. The data from commercial and small-scale beekeepers in Ontario was analyzed separately. Responses were received from 117 commercial beekeepers and 118 small-scale beekeepers which represents 40 per cent of beekeepers who received the survey.

By beekeeper type, responses were received from 63 per cent of commercial beekeepers representing 63,236 colonies and 30 per cent of small-scale beekeepers representing 1,287 colonies (Table 1 and Table 2). Combined, the responses represent 61 per cent of the total number of colonies registered in Ontario as of December 31, 2017. Although not reported to CAPA for inclusion in their 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. Both registered commercial and small-scale beekeepers in Ontario reported an approximate 46 per cent overwinter mortality during the winter of 2017-2018 (Table 2). In Canada, 15 per cent is the maximum level of overwinter loss 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 (Figure 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 largely 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 East region while small-scale beekeepers reported the highest losses in the Southern region. Overall, mortality during the 2017-2018 winter differed by approximately 0.2 per cent between commercial and small-scale beekeepers (Table 2).

Table 3. Number of commercial and small-scale beekeeper survey respondents and the overwinter mortality (per cent) in 2018 for each beekeeping region in Ontario.

Beekeeping Region
Commercial Beekeepers
Small-Scale Beekeepers
# of Respondents
Overwinter Mortality (%)
# of Respondents
Overwinter Mortality (%)
Central
41
52.8
29
44.2
East
23
56.2
36
45.1
North
5
42.0
17
45.3
South
36
43.6
27
50.7
Southwest
12
32.7
9
25.4
Total
117
45.7
118
45.5

When respondents were grouped by operation size (number of colonies managed), the honey bee mortality during the winter of 2017-2018 ranged from 41.6 to 46.8 per cent (Table 4). Beekeepers operating 201 to 500 colonies reported fewer honey bee colony losses (41.6 per cent) than other beekeepers. Similar to previous years, the number of respondents in the 501 to 1000 colonies category remained low, however the percent in overwinter mortality reported in this group tripled. The greatest number of survey respondents had beekeeping operations with fewer than 10 colonies and this group reported an overwinter honey bee mortality of 43 per cent. Unlike previous years, operations with greater than 1000 colonies reported the greatest overwinter honey bee mortality (~47 per cent).

Table 4. Overwinter honey bee mortality during the winter of 2017-2018 by size of beekeeping operation (number of colonies operated).

# of Respondents
# of Colonies Reported in the Fall of 2017
Average Overwinter Mortality (%)
75
<10
43.4
43
10-49
45.9
71
50-200
42.5
20
201-500
41.6
8
501-1000
45.3
18
>1000
46.8

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

Table 5. Number of commercial and small-scale beekeepers reporting contributing factors to honey bee colony mortality during the winter of 2017-2018.

Suspected Cause of Colony Loss
# of Commercial Beekeepers Reporting
# of Small-Scale Beekeepers Reporting
Starvation
30
21
Poor Queens
50
16
Weather
74
46
Ineffective Varroa control
34
14
Nosema
22
10
Weak Colonies in the Fall
36
30
Other
46
25
Don't know
24
27

Management Practices for Pests and Disease

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 2018 winter loss survey focused on the surveillance, management and monitoring of three major pest and disease 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 (Figure 2) and which treatments were used at the beginning (spring) and the end (fall) of the 2017 beekeeping season (Table 6).

Type of varroa monitoring method used by commercial and small-scale beekeepers in 2017. Survey respondents could reply with more than one answer.

Figure 2. Type of varroa monitoring method used by commercial and small-scale beekeepers in 2017. Survey respondents could reply with more than one answer.

Text Equivalent to Figure 2

Of the beekeepers who responded to the question regarding varroa monitoring, 84 per cent of commercial beekeepers and 75 per cent of small-scale beekeepers stated that they monitor for varroa infestation in their colonies. Of those, a number of monitoring 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. When the response "other" was selected, the beekeeper commonly reported that they visually check their colonies for varroa or use the sugar shake method, neither of which is recommended methods for monitoring varroa.

Ontario beekeepers use a variety of treatment options to manage varroa mites. In spring and fall of 2017, 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 oxalic acid. 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 bee- keepers 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 2017. Survey respondents could respond with more than one answer.

Varroa Treatment
Spring 2017
Fall 2017
# of Commercial Beekeepers
# of Small-Scale Beekeepers
# of Commercial Beekeepers
# of Small-Scale Beekeepers
Apistan® (fluvalinate)
5
5
15
5
CheckMite+™ (coumaphos)
0
1
0
0
Apivar® (amitraz)
33
11
57
17
Thymovar (thymol)
3
4
5
2
65% formic acid (40 ml multiple application)
29
9
29
12
65% formic acid (250 ml single application)
7
6
11
5
Mite Away Quick Strips (formic acid)
17
27
24
37
Oxalic acid
14
3
47
23
Other
11
7
3
6
None
25
47
4
29

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 survey respondents did not treat for nosema during 2017 (Table 7). Eighty one 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 80 per cent of respondents did not treat for the disease in the fall of 2017.

Table 7. Treatments reported by commercial and small-scale beekeepers used to control nosema in the spring and fall of 2017.

Nosema Treatment
Spring 2017
Fall 2017
# of Commercial Beekeepers
# of Small-Scale Beekepers
# of Commercial Beekeepers
# of Small-Scale Beekeepers
Fumagillin
20
17
21
22
Other
1
5
0
2
None
94
94
90
90

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 (74 per cent) who responded to this survey question treated for AFB during 2017 and the most common treatment reported was oxytetracycline (Table 8). Thirty one per cent of small-scale beekeepers reported treating for AFB in the spring and 40 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 to date 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 2017.

American Foulbrood Treatment
Spring 2017
Fall 2017
# of Commercial Beekeepers
# of Small-Scale Beekeepers
# of Commercial Beekeepers
# of Small-Scale Beekeepers
Oxytetracycline
80
35
75
43
Tylosin
0
0
0
0
Other
0
0
0
1
None
34
78
40
66

General Comments and Discussion

The annual 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 pests and diseases. Honey bee colony mortality differs from year to year, among different beekeeping regions as well as between individual beekeeping operations. This survey alone cannot paint a complete picture of honey bee health as honey bee health is complex and it is difficult to attribute overwinter losses to any 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

A number of actions have been taken by the provincial government, with ongoing efforts to support the sector including:

  • investing $1 million in innovative pollinator health research,
  • working to restore and protect 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 and best management and integrated pest management practices.

Additionally, commercial beekeepers have access to a production insurance plan to help them manage financial loss from overwinter bee colony damage or loss. 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. OMAFRA 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.

Ontario is also working collaboratively at the national level coordinating the winter loss survey with all other provinces and the Canadian Association of Professional Apiculturists. This has the advantage of leveraging consistent and accurate methods in gathering data, assessing pest, disease and management issues across Canada, while allowing for each province to focus on their own unique areas of interest and coordinate with existing programs. 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 mortalities higher than the national average (Figure 3).

Overwinter mortality (%) reported by beekeepers in Ontario (blue) and Canada (grey) from 2006-2007 to present.

Figure 3. Overwinter mortality (%) reported by beekeepers in Ontario (blue) and Canada (grey) from 2006-2007 to present.

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 an increase to 27 per cent and 46 per cent overwinter mortality in 2016-2017 and 2017-2018 respectively.

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 ontario.ca/beekeeping.

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.

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.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA
Creation Date: 17 August 2017
Last Reviewed: 18 December 2018