New U Guelph Research: Importing Queen Bees Won't Solve Canada's Beekeeping Challenges Due to Antibiotic Resistance

Canadian beekeepers face mounting pressures that threaten the sustainability of their operations and the crops reliant on honey bee pollination. From varroa mites ravaging colonies to harsh winters claiming thousands of hives, the industry grapples with multifaceted challenges. Recent university-led research underscores a critical vulnerability: the heavy reliance on imported queen bees, which fails to address core issues like antibiotic resistance and microbiome mismatches, potentially exacerbating colony losses.

Honey bees pollinate approximately one-third of Canada's food crops, contributing billions to the economy through fruits, nuts, oilseeds, and forage. Yet, annual winter losses averaging nearly 40 percent strain beekeepers, forcing them to rebuild colonies each spring. This cycle highlights the need for resilient, locally adapted stock, a focus of ongoing studies at institutions like the University of Guelph's Honey Bee Research Centre.

📊 Escalating Winter Losses Signal Systemic Issues

The Canadian Association of Professional Apiculturists (CAPA) annual surveys reveal stark trends. For the 2024-2025 winter, national losses reached 39.3 percent across 435,000 surveyed colonies, surpassing the long-term average of 27.7 percent. Provinces like New Brunswick (44.7 percent) and Saskatchewan (43.8 percent) fared worst, while Newfoundland and Labrador reported just 12.9 percent—attributable to the absence of varroa mites.

Ontario's 2025 survey echoed this, with total losses (winter plus in-season) at 39.3 percent, including 8.8 percent mid-season attrition. Smaller operations (<50 hives) lost 47.2 percent, compared to 37.4 percent for larger ones, pointing to scale-related management differences.

• Varroa destructor and associated viruses: Top cause in five provinces, driving immunosuppression and deformed wings.
• Poor queen quality: Cited in eight provinces, leading to supersedure or absconding.
• Weak fall colonies: Prevalent in eight regions, often from nutrition deficits.
• Weather extremes: Harsh in seven provinces, disrupting foraging and clustering.
• Starvation: Key in five areas, exacerbated by late flows.

These patterns persist into 2026, with preliminary data suggesting no relief, amid climate variability and pathogen evolution.

Varroa Mites: The Persistent Predator

Since invading Canada in the 2000s, Varroa destructor has become the arch-nemesis of honey bees. This parasitic mite feeds on fat bodies, transmitting viruses like deformed wing virus (DWV) that amplify mortality. CAPA identifies varroa as the primary winter loss factor in key provinces, with resistance to amitraz strips emerging—a global concern now documented in Canadian hives.

Beekeepers employ integrated pest management (IPM): alcohol washes for monitoring, treatments like formic or oxalic acid, and drone brood removal. Yet, late-season spikes overwhelm colonies, reducing overwintering success. University of Guelph researchers advocate genetic selection for varroa-resistant stock, integrating instrumental insemination for controlled breeding.

Queen Dependency: Imports Dominate Supply

A colony's queen dictates its fate—laying up to 2,000 eggs daily, emitting pheromones for cohesion, and shaping immunity. Canada produces insufficient queens during the April-September window, importing 260,000-300,000 annually from Hawaii, New Zealand, Australia, California, and Chile. These fill early-spring gaps but introduce risks: warmer-climate genetics poorly suit Canadian cold snaps, with imported queens 25 percent less likely to overwinter successfully.

Poor queens manifest as spotty brood, swarming, or collapse. CAPA surveys rank queen failure among top losses, compounded by shipping stress weakening vitality.

New U Guelph Research Exposes Antibiotic Pitfalls

A landmark Nature Sustainability study by University of Guelph's Brendan Daisley and colleagues analyzed CAPA data from 700,000+ colonies (2015-2023). Post-2018 regulations curbed antibiotics (oxytetracycline, tylosin, etc.) from 50 percent to 25 percent usage, aligning with WHO antimicrobial resistance (AMR) efforts. Paradoxically, overwintering mortality climbed from under 20 percent to over 40 percent.

This inverse correlation (r = -0.62) suggests dependency: antibiotics controlled diseases like American foulbrood (AFB, Paenibacillus larvae), but overuse bred resistance, now documented at nine percent in Alberta samples. Withdrawal without probiotics left microbiomes vulnerable, termed a 'microbial apocalypse.'

AFB spores persist decades; resistant strains spread via imports, robbing hives of brood. Canadian Food Inspection Agency (CFIA) screens queens, but microbiome disruptions persist.

Microbiome Mismatch in Imported Queens

Queens harbor distinct gut microbiomes influencing lifespan, fertility, and colony signals. Imported ones arrive with foreign communities, mismatched to Canadian forage, pathogens, and seasons—shaped by exporters' antibiotic histories. U Guelph's Canadian Bee Gut Project, co-led by Daisley and Emma Allen-Vercoe, maps these coast-to-coast, now prioritizing queens for overwintering biomarkers.

Early insights: disrupted microbiomes heighten Nosema, chalkbrood susceptibility. Probiotics emerge as alternatives, restoring balance without resistance risks.

Environmental Stressors Amplify Vulnerabilities

Beyond biology, nitrogen dioxide (NO₂) from diesel exhaust predicts 17.5 percent of mortality variance, degrading floral scents and starving foragers. Warmer winters (beneficial) contrast heavy snowfall (lethal). CAPA notes climate's role in seven provinces, delaying flows and treatment windows.

University-Led Breeding Initiatives

Canadian universities pioneer solutions. U Guelph's Honey Bee Research Centre advances queen banking, indoor rearing for climate-proof stock. UBC's $4.5 million project breeds nucleus colonies domestically. Université Laval and CRSAD select varroa-resistant genetics. U Manitoba's Honey Bee Lab tests stressors; Queen's West Campus Apiary models best practices.

Ontario Resistant Honey Bee Selection Program instruments insemination, yielding hygienic, mite-hardy lines.

Stakeholder Perspectives and IPM Strategies

Beekeepers via CAPA urge miticide rotation, monitoring thresholds under 3 percent varroa. Government funds surveillance; researchers push One Health—integrating human-animal-environmental factors. Probiotics, essential oils, breeding converge in IPM.

Photo by Richard Rivas on Unsplash

• Frequent monitoring: Alcohol washes, sticky boards.
• Nutrition boosts: Pollen patties, fall feeds.
• Wintering tech: Indoor storage, windbreaks.
• Microbial therapies: Targeted probiotics.

Future Outlook: Toward Self-Reliance

With losses unsustainable, domestic queen production must scale. U Guelph's microbiome tools promise resilient strains. Policy safeguards against import disruptions; investments in ag sci education ensure expertise. Balanced AMR mitigation with alternatives secures pollination, food security, and rural economies.

Collaborations like Food From Thought exemplify higher education's role, fostering innovations for thriving Canadian apiaries.