2019 Season highlights

The Ministry of Agriculture, Food and Rural Affairs’ (OMAFRA) Apiary Program conducted regular and targeted inspections focused on assessing the presence of the small hive beetle (SHB), which was identified in 26 new bee yards in the province.

Effective March 14th, 2019, the Chief Veterinarian for Ontario revoked the SHB quarantine that was established in 2011 for Essex and part of the municipality of Chatham-Kent. The removal of the quarantine allowed beekeepers with colonies in the quarantine area to resume normal business and hive movement activities, subject to the requirements of the Bees Act.

As a result of the quarantine revocation, the Apiary Program removed all standing orders restricting the movement of bees from yards that had been found positive for SHB. The quarantine was intended to mitigate and slow the spread of SHB within Ontario allowing the industry time to adapt to this manageable pest. With SHB establishing itself outside of the quarantined area, including in the region of Niagara, OMAFRA has shifted its focus from regulatory action to a risk-based management strategy that includes monitoring, testing, mapping, and education.

Approximately 30,706 honey bee colonies were shipped outside of Ontario for the pollination of blueberry and cranberry crops in eastern Canada.

Ontario beekeepers reported an overall overwinter honey bee mortality of 23% for the winter of 2018–2019. This was much lower than the overwinter mortality reported in the previous year (46%).

Notable statistics about the 2019 Ontario beekeeping industry include:

  • number of registered beekeepers: 2,570
  • number of registered colonies: 91,953
  • average honey yield/colony: 40 kg (88 lb) per colony
  • total estimated honey crop: 3.6 million kg (8.0 million lb)
  • overwinter honey bee losses reported by commercial beekeepers: 23%

Pest and disease levels

During the 2019 beekeeping season, OMAFRA inspected a total of 621 bee yards. The presence of common apiary pests and diseases was assessed by ministry apiary inspectors through the brood nest inspection of 4,988 colonies. Inspectors checked for varroa mites in 1,561 of the colonies receiving brood nest inspections and checked for small hive beetle in an additional 7,608 colonies through top bar inspections.

The prevalence of the following diseases among inspected colonies were:

  • American foulbrood: 0.82%
  • European foulbrood: 0.03%
  • sacbrood virus: 0.14%

American foulbrood (Paenibacillus larvae)

American foulbrood (AFB), a bacterial disease of honey bees, was detected in 41 honey bee colonies or 0.82% of the colonies inspected in Ontario. The 2019 data represents a decrease in AFB from 2018 when AFB was observed in 1.77% of colonies.

Sample analysis confirmed that the strains of AFB circulating in Ontario remain susceptible to oxytetracycline. This is good news since antibiotic resistant strains of AFB have been detected in other jurisdictions across Canada. Antibiotics are not a cure for AFB, rather they are to be used prudently as a management option to reduce the chances of clinical (observable) AFB infection becoming established in a colony. When a colony has clinical AFB, antibiotics are not effective, and all infected colonies must be destroyed.

AFB remains a very serious disease of honey bees with the potential to cause economic loss within a beekeeping operation and at a population level. Beekeepers who observe symptoms of AFB should contact their local Apiary Inspector immediately.

Small hive beetle (Aethina tumida)

SHB is an insect pest of honey bees. A total of 26 apiaries, both commercial (operating 50 or more colonies) and small-scale (operating 49 or fewer colonies), tested positive for SHB in Ontario. This represents a decrease in new detections in 2019 when compared to 2018 (n=35). Due to the high rate of inspection of colonies in the Niagara region to allow for the movement of colonies for out of province pollination, colonies in this region make up a large proportion of apiary inspections.

SHB is capable of damaging colonies when conditions are ideal and when colonies are not managed properly. However, there have been very few reports of SHB creating damage under Ontario conditions. The presence of larvae, which is the main cause of SHB damage to colonies, is documented during apiary inspections. Although SHB larvae has been found in honey bee colonies in Ontario, they are typically at low, non-damaging levels of infestation. Any potential impact from SHB will depend on the beekeeper’s management practices and specific environmental conditions that may allow beetle larvae to increase. To date, the impact of this pest in Ontario has been limited.

The province is maintaining its SHB management strategy, which is consistent with other jurisdictions with SHB. The ministry has an online map showing the number of SHB-positive bee yards confirmed in each township. This map not only provides current data to other jurisdictions that import Ontario honey bees, but also informs beekeepers about where SHB has been detected in Ontario, which helps them to manage the risk to their beekeeping activities.

Varroa mites (Varroa destructor)

The presence of varroa mites, which are parasitic mites of honey bees, is widespread in North America and they are found in apiaries across the province. This pest has been identified as the main culprit for the death and reduced populations of overwintered honey bee colonies in Ontario. Monitoring varroa mite infestation throughout the season continues to be essential for beekeepers to confirm the degree of infestation at key times in the season, to determine if and when treatments are needed to reduce varroa levels, what type of treatment may be required, and to determine if mite control methods were successful.

Ministry apiary inspectors sampling for varroa mites during regular apiary inspections typically documented low levels of infestation throughout the beekeeping season. Across the province, 1,561 (1,110 commercial, 451 small-scale) colonies were inspected for varroa mites using a standard alcohol wash (a sample of approximately 300 bees collected from the brood nest, washed in alcohol and the varroa mites filtered and quantified).

As varroa mites are widely distributed across the province, the prevalence of these mites is not as informative as the degree of infestation. Guzman et al. (2010) established treatment thresholds for varroa mite infestations. Colonies should be treated for varroa mites in:

  • May if the infestation is greater than 2%
  • August if the infestation is greater than 3%

The mean monthly varroa mite infestation of commercial honey bee operations.

Figure 1: Mean varroa mite infestation levels and treatment thresholds in Ontario commercial honey bee operations in 2019.

The mean monthly varroa mite infestation of small-scale honey bee operations.

Figure 2: Mean varroa mite infestation levels and treatment thresholds in Ontario small-scale honey bee operations in 2019.

Among commercial operations, the mean varroa mite infestation remained below treatment thresholds and ranged from a low of 0.04% in April to a high of 1.81% in October (Figure 1). The degree of varroa mite infestation among small-scale operations was variable, ranging from 0.07% in April to a high of 3.13% in October (Figure 2).

The data presented in Figures 1 and 2 represents the colonies inspected in 2019 and is not necessarily reflective of the beekeeping industry across the province. The low degree of infestation among commercial honey bee operations may confirm the success that some beekeepers have had with the management of varroa mites.

Some commercial operations, however, anecdotally reported high varroa mite infestations in late fall. While most of the colonies sampled (represented by mean) during inspection for varroa mites were below the treatment threshold in fall (3 varroa mites per 100 bees), there were colonies that were above the threshold. This demonstrates that some colonies were likely going into the winter with damaging levels of varroa mite infestation.

Compared to commercial beekeeping operations, fewer colonies operated by small-scale beekeepers were inspected. This resulted in smaller sample sizes, particularly for August, September and October when 32, 43 and 37 colonies were sampled for varroa respectively. Small sample sizes may have contributed to the observed increase in mean varroa mite infestation for small-scale operations in August, September and October.

This report highlights the importance of late season monitoring for varroa mites, both in September and in October, after varroa mite treatment has been applied, to ensure that the treatment was effective at lowering the level of infestation.

Treatments for varroa mites

Treatments for varroa mites and any other pest or disease must be legally registered in Canada for use, including the product, the active ingredients and the application method(s). For effective treatment of varroa mites and to reduce the development of resistant populations, beekeepers must follow label directions when using control products. For example, if the label says to use 1 strip of an acaricide per 5 frames of bees, then a double brood chamber needs 4 strips. The Treatment options for honey bee pests and diseases in Ontario lists the only methods that should be used.

Beekeepers have had access to Bayvarol®, a synthetic strip product which uses the active ingredient flumethrin, since 2018 and another product, Hopguard2®, which uses hops extracts, was registered in Canada in October 2019 and will be available to beekeepers for use in the 2020 beekeeping season.

Honey production

Honey survey questionnaires were mailed to registered Ontario commercial beekeepers to estimate the average honey production in the province. Responses were received from 20% of commercial beekeepers, representing 12,500 colonies across the province.

Based on the responses, the estimated average honey production in Ontario was 39.8 kg (87.7 lb) per colony. This is a slight increase in honey production from 2018 (36.9 kg or 81.4 lb per colony).

Pollination services

There is a demand for Ontario honey bee colonies for pollination services for berry crops in eastern Canada (Quebec, New Brunswick, Nova Scotia and Prince Edward Island). Approximately 30,706 honey bee colonies were moved from Ontario to eastern Canada in 2019 for the purpose of pollination. This number is up from the 21,620 honey bee colonies that left the province in 2018 for pollination services.

To ensure the demand for pollination services continued to be met, Ontario and the eastern Canadian provinces again worked collaboratively to develop additional pre-transportation inspection requirements before colonies were shipped across provincial borders, which allowed for the continued movement of Ontario honey bee colonies. The spread of SHB from regions in Ontario to eastern Canada remained a concern for inspection requirements in 2019.

Honey bee mortality

Overwinter honey bee mortality

During the spring of 2019, a survey was used to estimate overwinter honey bee colony losses. The survey was distributed to 218 registered commercial beekeepers. Responses were received from 40% of the beekeepers surveyed representing 48,418 colonies across the province. Based on the results of the survey, commercial beekeepers reported an approximate 23% overall honey bee colony loss during the 2018–2019 winter. This was a sizeable decrease from the 46% winter loss reported in the previous year (2017–2018).

In Canada, 15% is considered the maximum acceptable winter loss. Similarly, small-scale beekeepers reported a 26% winter loss. See the full report on 2019 overwinter losses.

In-season honey bee mortality

Starting in spring of 2017, Ontario beekeepers were encouraged to report in-season honey bee mortality incidents to OMAFRA’s Agricultural Information Contact Centre. A honey bee incident is defined as atypical effects characterized by bee mortality, or sub-lethal effects observed in a honey bee colony and suspected by a beekeeper to be related to pesticide exposure. In 2019, OMAFRA received 10 in-season honey bee mortality incident reports.

Antimicrobial use in the apiculture industry

As of December 1st, 2018, beekeepers need to obtain a veterinary prescription, which involves establishing a veterinarian-client-patient relationship, to purchase products including oxytetracycline and tylosin (both used to prevent AFB and European foulbrood) as such products are only available for legal purchase from a veterinarian or pharmacist.

For general information on antimicrobial use in agriculture visit the Antimicrobial Resistance in Agriculture webpage. For more specific information on antibiotics for beekeeping in Ontario refer to the Ontario Beekeepers’ Association’s Antibiotic Access Resources for Beekeepers.