2018 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 35 bee yards in the province. The SHB quarantine area (Essex and part of Chatham-Kent) remains in place.

Approximately 21,620 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 46% for the winter of 2017–2018. This was much higher than the overwinter mortality reported in the previous year (27%).

Notable statistics about the 2018 Ontario beekeeping industry include:

  • number of registered beekeepers: 3,026
  • number of registered colonies: 100,413
  • average honey yield/colony: 37 kg (81 lb) per colony
  • total estimated honey crop: 3.7 million kg (8.2 million lb)
  • overwinter honey bee losses reported by commercial beekeepers: 46%

Pest and disease levels

During the 2018 beekeeping season, OMAFRA inspected a total of 749 bee yards. The presence of common apiary pests and diseases was assessed by ministry apiary inspectors through the brood nest inspection of 4,700 colonies. Inspectors checked for varroa mites in 2,256 of the colonies receiving brood nest inspections and checked for SHB in an additional 15,677 colonies through top bar inspections. The prevalence of the following diseases among inspected colonies were:

The prevalence of the following diseases among inspected colonies were:

  • American foulbrood: 1.77%
  • European foulbrood: 0.00%
  • sacbrood virus: 0.11%

American foulbrood (Paenibacillus larvae)

American foulbrood (AFB), a bacterial disease of honey bees, was detected in 83 honey bee colonies or 1.77% of the colonies inspected in Ontario. This does not include 6 colonies which were incorrectly documented, due to a data entry error, as being infected with AFB. The 2018 data represents an increase in AFB from 2017 when AFB was observed in 1.18% of inspected colonies.

Of further interest, the prevalence of AFB increased almost 4-fold from 2016 to 2018. This highlights the need for beekeeper vigilance on this serious disease of honey bee brood. The increase may or may not reflect the true prevalence in the population as the inspections are largely the result of beekeepers requesting inspections for permits or for the follow-up on disease risks identified to the Apiary Program.

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 35 apiaries, both commercial (operating 50 or more colonies) and small-scale (operating 49 or fewer colonies), tested positive for SHB in Ontario. This represents an increase in new detections in 2018 when compared to 2017 (n=18). Due to the high rate of inspection of colonies in the Niagara region to allow for the movement of colonies out of Ontario for pollination services, 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. Through a SHB working group (comprised of representatives from the beekeeping sector, technology transfer specialists and government representatives), OMAFRA is collaborating with industry specialists and other provinces on options to limit the spread of SHB and mitigate the economic impact of this pest on Ontario’s beekeeping industry.

The ministry has an online map showing the number of SHB-positive bee yards confirmed in each township. This map provides current data for other jurisdictions that import Ontario honey bees and 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, 2,256 (1,807 commercial, 449 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 2018.

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 2018.

Among commercial operations, the mean varroa mite infestation remained below treatment thresholds and ranged from a low of 0.05% in May to a high of 0.94% in September (Figure 1). The degree of varroa mite infestation among small-scale operations was variable, ranging from a low of 0.10% in May to a high of 3.53% in October. The mean varroa mite infestation for small-scale operations was above recommended treatment thresholds in August (Figure 2).

The data presented in Figures 1 and 2 represents the colonies inspected in 2018 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 April and October when 11 and 10 colonies sampled for varroa respectively. Small sample sizes may have contributed to the observed increase in mean varroa mite infestation for small-scale operations in April 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 may have access to additional registered treatments soon. Bayvarol® is a synthetic strip product which uses the active ingredient flumethrin and was registered for use in Canada in November 2016. This product was available for the 2018 beekeeping season. Another product, Hopguard2®, which uses hops extracts, has recently been submitted for registration in Canada.

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 30% of commercial beekeepers, representing 23,000 colonies across the province.

Based on the responses, the estimated average honey production in Ontario was 36.9 kg (81.4 lb) per colony. This is a major increase in honey production from 2017 (19.3 kg or 43.0 lb per colony) and above the previous 5-year average.

Pollination services

In recent years, the demand for pollination services for berry crops in eastern Canada (Quebec, New Brunswick, Nova Scotia and Prince Edward Island) had been trending upwards until 2017. The number of honey bee colonies leaving Ontario to pollinate crops in eastern Canada increased from 12,600 colonies in 2010, to 38,000 colonies in 2016. In 2017, a decrease in the market demand and price for wild blueberries contributed to a decrease in the demand for honey bee colonies being contracted from Ontario for pollination services, a trend which continued in 2018. Approximately 21,620 honey bee colonies were moved from Ontario to eastern Canada in 2018 for the purpose of pollination.

To ensure the demand for pollination services continued to be met, Ontario and the eastern Canadian provinces 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. Of particular concern for inspection requirements was the spread of SHB from regions in Ontario to eastern Canada.

Honey bee mortality

Overwinter honey bee mortality

During the spring of 2018, a survey was used to estimate overwinter honey bee colony losses. The survey was distributed to 186 registered commercial beekeepers. Responses were received from 63% of the beekeepers surveyed representing 63,236 colonies across the province. Based on the results of the survey, commercial beekeepers reported an approximate 46% overall honey bee colony loss during the 2017–2018 winter. This was a big increase from the 27% winter loss reported in the previous year (2016–2017).

In Canada, 15% is considered the maximum acceptable winter loss. Small-scale beekeepers also reported a 46% winter loss. See the full report on 2018 overwinter losses.

In-season honey bee mortality

From 2012 to 2016, in-season incidents were reported to Health Canada’s Pest Management Regulatory Agency. Starting in spring of 2017, Ontario beekeepers were encouraged to report in-season honey bee mortality incidents to OMAFRA’s Agricultural Information Contact Centre. Reported incidents are shared between OMAFRA, the Ministry of Environment, Conservation and Parks, and Health Canada.

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 2018, OMAFRA received 16 in-season honey bee mortality incident reports.

Antimicrobial use in the apiculture industry

The federal government implemented amendments to the Food and Drug Regulations and policies in 2018 to increase veterinary oversight of antimicrobials. One significant change has moved antimicrobials deemed important to human medicine to Health Canada’s prescription drug list, thereby requiring a veterinary prescription for purchase.

This change applies to all producers who purchase products containing medically important antimicrobials, including beekeepers. Enforcement began on December 1st, 2018. Beekeepers now 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). These prescription products will only be available for purchase from a veterinarian or pharmacist.

The Ontario government has worked with stakeholders, including the apiculture industry, to inform them of the changes and facilitate relationships and communication with the College of Veterinarians of Ontario as beekeepers navigate new rules around access to needed products and to foster veterinary access to apiary knowledge and expertise. To this end, the Ontario Beekeepers’ Association also led a working group with the College of Veterinarians, the Ontario Veterinary Medical Association, commercial beekeepers, veterinarians, researchers and government and non-government specialists. 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.