This past weekend, the Atlantic Tech Transfer Team for Apiculture attended the 2026 Atlantic Bee Tour, hosted by the Prince Edward Island Beekeepers Association in Charlottetown, Prince Edward Island. With 50 attendees, the event brought together beekeepers, industry members and researchers from across the region. As in previous years, the Atlantic Bee Tour served as an important opportunity for beekeepers to network, learn, and share knowledge. This event included industry updates, hands-on demonstrations and visits to local businesses, all showing the essential role of honey bees in the Atlantic region.

Review of the Atlantic Bee Tour 2026

The first day of the tour consisted of presentations and educational learning about current challenges, industry updates and important information to help other beekeepers. Stephen Farmer, a local beekeeper from PEI and executive member of the PEIBA board, started off the event with an introduction and to say thank you to everyone involved. Cameron Menzies, PEI Provincial Apiarist, opened the morning with an update on the state of beekeeping in the province. He noted that PEI is home to roughly 5,000 commercial hives, used for honey production, pollination, or both, and that the province continues to face significant overwintering challenges. The 2025-2026 winter losses were driven primarily by weak colonies going into fall, harsh weather conditions, poor queens, and starvation. Despite these setbacks, Cameron shared encouraging results from the 2025 summer inspections, which showed low Varroa mite levels, no small hive beetle, and only low levels of European foulbrood. He also emphasized the importance of wild blueberry pollination in PEI, which relies on a 1:1 ratio of local hives to imported hives, showing how important local pollinators are for growers across the province.

Figure 1: Cameron Menzies Presenting (ATTTA ©, 2026)

Following Cameron’s update, attendees heard from Lauren Park of the Canadian Honey Council, who provided a national perspective on current industry priorities. She outlined topics the council focuses on, like miticide registration, pollination issues, and national policy discussions. Lauren also addressed concerns surrounding honey adulteration and importation issues. Lauren also highlighted upcoming industry events, including the 2027 Pollination Symposium in Quebec.

Figure 2: Lauren Park Receiving a gift on behalf of the PEIBA (ATTTA ©, 2026)

The Atlantic Tech Transfer Team for Apiculture shared updates on disease monitoring and research, including Varroa mite surveys, amitraz efficacy testing, and ongoing work related to emerging pathogens such as Vairimorpha (formerly Nosema) and Lotmaria passim. These updates offered attendees a clear picture of the scientific work underway to support evidence‑based management practices throughout the region.

Jeff Lee from Honey Bee Zen Apiaries discussed his own operation in British Columbia, sharing his knowledge of different forages and cover crops to improve forage density and pollinator pathways; this approach is used to strengthen both honey bee and wild pollinator health. Amanda Goodman Lee shared an engaging session on honey marketing, explaining why local honey remains a strong competitor in the market and how producers can communicate value to customers. Also, Jeff and Amanda both talked about tricks they have learned from their beekeeping experience.

The afternoon sessions shifted toward practical demonstrations and applied learning. Karen Thurlow led a microscopy display, showing participants how to prepare slides, identifying Vairimorph, and showed different types of pollen found in colonies. She also shared practical tips from her own operation, offering guidance on efficient equipment use and management strategies. The first day was filled with a balance of scientific and practical learning, providing attendees with lots of informational knowledge.

Figure 3: Fireweed Pollen Under a Microscope (ATTTA ©, 2026)

The second day of the Atlantic Bee Tour brought participants on a bus, showing diverse beekeeping and honey-related companies in PEI. The morning began at Ella’s Forest, where attendees toured the facility and learned about the dried wild blueberry products made. Then followed an in-hive demonstration for determining hygienic behaviour. From there, the group travelled to Red Island Cider for a behind-the-scenes tour of their production facility. The cidery even created a special honey-infused cider for the Bee Tour!

Figure 4: Products from Ella’s Forest (ATTTA ©, 2026)

Figure 5: In-Hive Demonstration of UBeeO® by Stephen Farmer (ATTTA ©, 2026)

After lunch at Founder’s Hall, the tour continued to Island Honey Wine Co. where participants sampled a variety of meads, learned about the business and had a chance to tour the area. This trip showed the diversity of how honey and in-hive products can be transformed into innovative products! The final destination of the tour was at a local beekeeper’s operation, Jason and Monica Campbell. Then the tour ended at New Glasgow for a delicious lobster supper!

Figure 6: Photos from the Island Honey Wine Co. (ATTTA ©, 2026)

The Atlantic Bee Tour was a great event for beekeepers across the region, offering valuable opportunities for learning and meeting members of the industry. The ATTTA team extends sincere thanks to the PEI Beekeeper’s Association for hosting this amazing event. We will look forward to the next Atlantic Bee Tour in 2028.

 Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email attta@perennia.ca

Wax is one of the most important structural components of a honey bee colony. It is the footing of what goes on inside the hive, from storing pollen and nectar to allowing bees to complete their life cycle. As comb ages through repeated brood cycles, its physical properties change. Comb darkens due to the accumulation of debris, and older comb (typically 4-5 years old) can retain substances that affect colony health. Regular comb replacement is an important management practice for maintaining healthy colonies. 

Wax and Comb as Reservoirs for Accumulation of Agrichemicals, Pests, and Disease

Beeswax is a lipid-based material composed primarily of fatty acid esters, hydrocarbons and free fatty acids ¹. Wax allows lipophilic, fat‑soluble compounds, to bind to it ². Wax also has a porous structure that allows residues to adsorb and persist within the comb ¹. Contaminants such as spores, debris and agrochemical residue can become trapped in comb and remain there for long periods ^3,4.  Once built, honey bees do not readily remove or metabolize wax, so contaminants accumulate over time.

Figure 1: Frame being pulled out of a hive (ATTTA ©, 2021)

Several honey bee diseases can persist in wax and brood comb. European foulbrood (EFB), caused by Melissococcus plutonius, remains viable in comb for several years ⁵.  The bacterium has also been shown to be present in symptomless colonies due to its persistence in wax debris, indicating ongoing contamination within a colony ⁶.  Experimental work has demonstrated that adult bees become colonized after ingesting approximately 10,000 bacterial cells per bee, meaning that even moderate contamination of wax debris can cause infection ¹⁰.

American foulbrood (AFB), caused by the spore-forming bacterium Paenibacillus larvae, is another disease that can persist in comb. This is because the spore stage of this bacterium is extremely resilient to the environment, surviving in wax, propolis and honey for up to 80 years ⁷. Honey bee larvae can become infected after ingesting as few as ten spores, so even trace contamination of brood comb can initiate disease ¹¹. 

Chalkbrood caused by the fungus Ascosphaera apis also leaves long-lasting spores. These spores remain in hive material for up to 15 years ⁷. Spores present in comb can infect developing brood due to the durability of the spores. Experimental work has shown that approximately 1000 spores per larva are enough to establish infection, meaning that contaminated wax can easily maintain the disease when environmental conditions favour growth of the fungus ¹².  

Vairimorpha (formerly Nosema) spp. also interact with hive materials. Vairimorpha spores can remain viable for up to a year in honey and fecal material, even at freezing temperatures ^7,8. A study has shown that the minimum dose capable of causing a detectable infection can be as low as 1.28 spores per bee, with a median infective dose of 149 spores per bee ¹³. Adult bees defecate inside the hive during cold weather, so Vairimorpha spores can accumulate on comb surfaces and be ingested by other bees over time.

Figure 2: Dark comb (ATTTA ©, 2021)

Recent research has shown that wax from dead colonies can contain detectable levels of honey bee viruses, including Deformed Wing Virus and Black Queen Cell Virus for at least 30 days ⁹.  Freezing does not reduce viral load, and only high-dose electron beam irradiation (35-45kGy) has been shown to decrease virus levels ⁹. This research is still developing, and it is unknown how significant this is for transmission inside hives, but important for beekeepers to be aware of. 

Wax can also absorb agrochemicals used inside and outside of the hive. Residues from Varroa mite treatments, as well as other insecticides, fungicides and herbicides, have all been detected in comb ⁴. Some compounds have been found to occur at high concentrations,  including amitraz residue, a product applied by beekeepers for treating Varroa mites, ranging from 5 to 464 µg/kg, and insecticides ranging from 1 to 464 µg/kg, brought in by foragers ⁴. Even when agrochemicals degrade, their metabolites can remain in wax. Chronic, low-level exposure may contribute to sublethal effects on honey bee health and allow pests to develop resistance.

Comb older than 4-5 years can accumulate pathogens, viral particles and agrochemical residue because honey bees never remove or replace it themselves. Regular comb replacement is one of the most effective ways beekeepers can reduce buildup and support healthier colonies. A future blog will explore comb rotation in more detail and how beekeepers can use it to maintain cleaner, safer hives for honey bees. 

 Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email attta@perennia.ca

 

References:

1. Meng, Q., Huang, R., Yang, S., Jiang, W., Tian, Y. and Dong, K., 2025. An Overview of the Adverse Impacts of Old Combs on Honeybee Colonies and Recommended Beekeeping Management Strategies. Insects, 16(4), p.351.
2. Atlantic Tech Transfer Team for Apiculture, 2017. Comb Rotation. https://www.perennia.ca/wp-content/uploads/2018/04/11-comb-rotation-eng.pdf
3. Wu, J.Y., Anelli, C.M. and Sheppard, W.S., 2011. Sub-lethal effects of pesticide residues in brood comb on worker honey bee (Apis mellifera) development and longevity. PloS one, 6(2), p.e14720.
4. López, S.H., Lozano, A., Sosa, A., Hernando, M.D. and Fernández-Alba, A.R., 2016. Screening of pesticide residues in honeybee wax comb by LC-ESI-MS/MS. A pilot study. Chemosphere, 163, pp.44-53.
5. León-Door, A.P., Pérez-Ordóñez, G., Romo-Chacón, A., Rios-Velasco, C., Órnelas-Paz, J.D., Zamudio-Flores, P.B. and Acosta-Muñiz, C.H., 2020. Pathogenesis, epidemiology and variants of Melissococcus plutonius (Ex White), the causal agent of European foulbrood. Journal of Apicultural Science, 64(2), pp.173-188.
6. Budge, G.E., Barrett, B., Jones, B., Pietravalle, S., Marris, G., Chantawannakul, P., Thwaites, R., Hall, J., Cuthbertson, A.G. and Brown, M.A., 2010. The occurrence of Melissococcus plutonius in healthy colonies of Apis mellifera and the efficacy of European foulbrood control measures. Journal of invertebrate pathology, 105 (2), pp.164-170.
7. Sammataro, D. and Avitabile, A. 2021. A Beekeeper’s Handbook: Fifth Edition. Cornell University Press
8. MacInnis, C.I., Keddie, B.A. and Pernal, S.F., 2020. Nosema ceranae (Microspora: Nosematidae): a sweet surprise? Investigating the viability and infectivity of N. ceranae spores maintained in honey and on beeswax. Journal of Economic Entomology, 113(5), pp.2069-2078.
9. Colwell, M.J., Pernal, S.F. and Currie, R.W., 2024. Treatment of waxborne honey bee (Hymenoptera: Apidae) viruses using time, temperature, and electron-beam irradiation. Journal of Economic Entomology, 117(1), pp.34-42.
10. Sebastian Jose, M., Bezerra da Silva, M.C., Obshta, O., Masood, F., Thebeau, J.M., Biganski, S., Raza, M.F., Camill, M.P., Prieto, E.T., Edirithilake, T. and Kozii, I., 2025. Antimicrobial control and temporal dynamics of M. plutonius colonization in adult worker honey bees (Apis mellifera). PLoS One, 20(5), p.e0322770.
11. Locke, B., Low, M. and Forsgren, E., 2019. An integrated management strategy to prevent outbreaks and eliminate infection pressure of American foulbrood disease in a commercial beekeeping operation. Preventive Veterinary Medicine, 167, pp.48-52.
12. Knoblauch, T., Jensen, A.B., Mülling, C.K., Aupperle-Lellbach, H. and Genersch, E., 2024. Chalkbrood Disease Caused by Ascosphaera apis in Honey Bees (Apis mellifera)—Morphological and Histological Changes in Infected Larvae. Veterinary Sciences, 11(9), p.415.
13. McGowan, J., De la Mora, A., Goodwin, P.H., Habash, M., Hamiduzzaman, M.M., Kelly, P.G. and Guzman-Novoa, E., 2016. Viability and infectivity of fresh and cryopreserved Nosema ceranae spores. Journal of microbiological methods, 131, pp.16-22.

Vairimorpha (formerly Nosema) disease is caused by the microsporidia parasites, V. ceranae and V. apis, which attack the gut tissue of honey bees. This parasite is one of the most common gut infections in honey bees, and many beekeepers rely on Fumagilin-B ® as treatment. Understanding what fumagillin is and how it functions can allow beekeepers to make informed decisions for managing this disease.

The mode of action for Nosema treatment Fumagillin

Fumagillin has been used by beekeepers since the 1950s to treat V. apis, and it is also successful in controlling V. ceranae ¹. Fumagillin is isolated from the fungus Aspergillus fumigatus and is an effective compound that works against microsporidia ². However, fumagillin on its own is unstable in water and breaks down quickly³. For this reason, commercial products (e.g., Fumagilin-B ®) are formulated as fumagillin dicyclohexylamine. Dicyclohexylamine (DCH) is a salt that increases the stability of the fumagillin compound, so it can be mixed into sugar syrup ³. The DCH portion is not the active ingredient against Vairimorpha, it simply protects fumagillin long enough for bees to consume it.

Figure 1: Fumagilin-B ® Product (Country Fields ©)

Once ingested by bees, fumagillin acts on the parasite’s growing stage, when it replicates inside the midgut ⁷. It works by binding to methionine aminopeptidase-2 (MetAP2), which is an enzyme microsporidia needed to process new proteins ⁴. Fumagillin binds to MetAP2 through a covalent bond, interfering with the parasite's ability to function normally ⁴. Without a working MetAp2 enzyme, the parasite cannot grow in the gut, and spore production drops.

Because fumagillin targets the parasites’ active stage, it does not kill spores directly. Instead, it reduces the number of new spores being produced inside the bee and over time, this lowers the overall spore load in the colony. Fumagillin is most effective when the colony is active, and bees are consuming the treated syrup, which allows the product to reach the midgut where the parasite grows.

Seasonal timing plays an important role in how well fumagillin works. In the Maritimes, colonies are most responsive to treatment in the spring when they are building up their colony and actively taking syrup. This is also the period when spore levels tend to be highest in Canada ^5,6. Treating during this time helps reduce the number of new spores produced inside the bees.

Some beekeepers apply fumagillin in the fall to help reduce infection heading into winter. Fall treatment can lower spore loads before overwintering, but fumagillin does not eliminate spores already present on the comb or in the hive environment ⁷. Research shows that fumagillin’s effect on spore loads is temporary because it only suppresses the actively growing stages of the parasite, once medicated syrup is no longer being consumed, spore levels may rise again if contamination persists. Because Vairimorpha spores are environmentally resistant and can persist on comb and hive surfaces, reinfection can still occur after being treated. Regular monitoring helps confirm whether treatment has been effective and if additional management is needed.

Fumagillin remains a useful tool for managing Vairimorpha spores when applied according to label directions, it can reduce spore production inside infected bees, but it does not kill spores already present in the environment of the hive. Understanding how fumagillin works, spore dynamics and why monitoring matters helps beekeepers make informed decisions about treating bees. 

Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email attta@perennia.ca

References:

1. Higes, M., Nozal, M.J., Alvaro, A., Barrios, L., Meana, A., Martín-Hernández, R., Bernal, J.L. and Bernal, J., 2011. The stability and effectiveness of fumagillin in controlling Nosema ceranae(Microsporidia) infection in honey bees (Apis mellifera) under laboratory and field conditions. Apidologie, 42(3), pp.364-377.
2. Van den Heever, J.P., Thompson, T.S., Curtis, J.M., Ibrahim, A. and Pernal, S.F., 2014. Fumagillin: an overview of recent scientific advances and their significance for apiculture. Journal of agricultural and food chemistry, 62(13), pp.2728-2737.
3. Food and Agriculture Organization of the United Nations & World Health Organization. 2024. Fumagillin dicyclohexylamine: Residue Monograph prepared by the meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), 98th Meeting 2024. FAO JECFA Monographs, 33. Retrieved May 6^th , 2026, from https://www.fao.org/fileadmin/user_upload/vetdrug/docs/1_dd405a226d1d1d0c1921a14367b6c989.pdf
4. Guruceaga, X., Perez-Cuesta, U., Abad-Diaz de Cerio, A., Gonzalez, O., Alonso, R.M., Hernando, F.L., Ramirez-Garcia, A. and Rementeria, A., 2019. Fumagillin, a mycotoxin of Aspergillus fumigatus: biosynthesis, biological activities, detection, and applications. Toxins, 12(1), p.7.
5. McCallum, R., Olmstead, S., Shaw, J. and Glasgow, K., 2020. Evaluating efficacy of Fumagilin-B® against nosemosis and tracking seasonal trends of Nosema spp. in Nova Scotia honey bee colonies. Journal of Apicultural Science, 64(2), pp.277-286.
6. Emsen, B., De la Mora, A., Lacey, B., Eccles, L., Kelly, P.G., Medina-Flores, C.A., Petukhova, T., Morfin, N. and Guzman-Novoa, E., 2020. Seasonality of Nosema ceranae infections and their relationship with honey bee populations, food stores, and survivorship in a North American region. Veterinary sciences, 7(3), p.131.
7. Pernal, S.F. and Clay, H. 2013. Honey Bee Diseases & Pests, Third Edition. Canadian Association of Professional Apiculturists, Beaverlodge, AB, Canada, 68 pp.

Ticks Safety in the Apiary

Ticks are an increasing concern for people in Atlantic Canada, and beekeepers are particularly at high risk with long hours spent in fields, wooded areas, and tall grass, which are all habitats for ticks. Understanding tick risks, and associated disease prevention strategies, is essential for beekeeper’s health.

Tick Safety in the Apiary

The Maritimes are home to many types of ticks, but the black-legged tick (Ixodes scapularis) is the only one currently known to transmit disease to humans. These include Lyme disease, caused by the bacteria Borrelia burgdorferi, as well as anaplasmosis, babesiosis and Powassan virus disease ¹. Both Lyme disease and anaplasmosis are now considered endemic diseases in Nova Scotia ¹. Other ticks found in the Maritimes include the American Dog tick (Dermacentor variabilis) and the groundhog tick (Ixodes cookei). While these species can carry pathogens, they are not known to transmit diseases to humans in the Maritimes ².

Figure 1: Most Commonly Found Ticks in the Maritimes Showing (Left to right) the Black-legged Tick, Groundhog Tick and Dog Tick (Government of Nova Scotia ©, 2026) (Retrieved May 20, 2026)

Ticks in Nova Scotia and New Brunswick are active when the temperature is consistently above freezing and can be found in woods, shrubs, leaf litter, long grass and gardens ¹. With a warming climate, black-legged ticks have expanded their range, meaning even beekeepers who have not encountered ticks in previous seasons should be aware of the risks ².

Ticks develop through four life stages: egg, larva, nymph and adult ³. Black-legged ticks feed on many hosts, including dogs, deer, rodents, birds and humans, allowing disease-causing bacteria to spread ³. Both nymphs and adults feed on animals and can spread diseases to humans.

Beekeepers can reduce the risk by taking precautions such as dressing appropriately, using repellents, managing the landscape of the apiary, managing tick hosts and doing thorough tick checks. When working in an apiary, an effective strategy is wearing correct clothing such as closed-toed shoes, long pants, long sleeves, and light-colored clothing to make ticks easier to spot, and tucking pants into socks or wearing tall boots to create physical barriers. Many of these practices also overlap with sting-prevention, making them easy to integrate into routine beekeeping strategies.

Repellents are another important step, but you must be careful that they will not disturb the bees ⁴. Using products that contain DEET or icaridin (picaridin) can be applied to exposed skin and clothing, and permethrin can be used on clothing to repel ticks on contact.  Make sure to follow label instructions when using these products. After spending time outdoors, beekeepers should perform tick checks, especially checking warm places on the body, as well as showering or bathing, and drying outdoor clothes on high heat to kill any ticks that may be attached.

Figure 2: Vegetation Management in an Apiary to Minimize Tick Habitat (Perennia ©, 2024)

Managing the environment of the apiary can also help reduce the risk of tick encounters. Keeping grass mowed, maintaining clear pathways to colonies, and placing hives on pallets or stands can make these areas less attractive to ticks ⁴. Some beekeepers also use gravel in the apiary to reduce vegetation around the hives and make the area less suitable for ticks. Reducing tick hosts, such as deer, small mammals and rodents, by using fencing or reducing rodent habitats around the apiary can lower the number of ticks around the bee yard. Together these prevention strategies create a safer work environment and can help beekeepers remain healthy.

 Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email attta@perennia.ca

References:
1.    Government of Nova Scotia. (n.d.). Tick safety. Available at https://novascotia.ca/ticksafety/  (Accessed: 19/05/2026)
2.    Nova Scotia Zoonotic Diseases Technical Working Group. (2026). Tick-borne Diseases Response Plan. Available at https://novascotia.ca/dhw/cdpc/documents/Tick-Borne-Disease-Response-Plan.pdf (Accessed: 19/05/2026)
3.    Ogden, N.H., Koffi, J.K., Pelcat, Y. and Lindsay, L.R., 2014. Environmental risk from Lyme disease in central and eastern Canada: a summary of recent surveillance information. Canada Communicable Disease Report, 40(5), p.74.
4.    Kopco, J., Struckhoff, E. and Underwood, R. (2025). Tick Prevention for Beekeepers. PennState Extension. Available at https://extension.psu.edu/tick-prevention-for-beekeepers (Accessed: 19/05/2026)

Understanding Vairimorpha Disease in Honey Bees

Honey bees depend on a healthy gut to digest food, absorb nutrients and maintain a strong immune system. When parasites invade this part of the digestive system, they can disrupt these processes and weaken the entire colony. One of the most common gut parasites found in honey bees is Vairimorpha (formerly Nosema), a microsporidian that infects honey bees and harms their colonies.

Understanding Vairimorpha in Honey Bees

Vairimorpha disease is caused by two spore-forming species, Vairimorpha ceranae and Vairimorpha apis. These parasites infect the epithelial cells of the honey bees’ ventriculus (midgut), where digestion and nutrient absorption take place ¹. As these cells become damaged, bees struggle to process food efficiently, which can shorten worker lifespan and weaken colony productivity ¹. Because the infection is internal, honey bees do not show outward symptoms specific to this disease, making this disease easy to overlook without testing. 

Figure 1: Vairimorpha spp. spore (arrow) under a compound microscope 100x

Even without obvious clinical signs, Vairimorpha infections can influence colony performance. Reduced nutrient absorption can weaken foraging ability, lower honey yield and slow spring build-up ¹. Classic symptoms such as fecal staining have been associated with V. apis ². The dominant species in Canada, V. ceranae, does not have distinct symptoms ². This makes visual inspection alone not reliable for detecting this disease and shows the importance of routine monitoring. 

The microsporidian spreads easily within a colony because the spores are environmentally resistant and spread through fecal-oral transmission. Bees can ingest the spores while cleaning contaminated comb, grooming or by trophallaxis ². Foragers can also pick up the spores from contaminated water sources ². Once inside the gut, the spores infect the midgut and multiply, allowing infection to spread quickly. Since this disease is transmitted through normal social behaviours, even strong colonies can become infected without showing obvious signs.

For decades, these pathogens were referred to as Nosema apis and Nosema ceranae. However, recent genomic work has shown both species are more closely related to the genus Vairimorpha, clustering with Vairimorpha necatrix, rather than the species Nosema bombycis in the genus Nosema ³. Although the scientific names have changed, the disease is still commonly referred to as Nosema or Nosemosis in the apiculture industry. It is important to note that this taxonomic update does not change how the disease is diagnosed or managed. 

Across Canada, research shows a clear shift toward V. ceranae being the dominant species. In a study on Nova Scotia colonies, all positive Vairimorpha samples contained V. ceranae, with V. apis not detected at all ⁴. Similar reports in other provinces, such as Ontario and Alberta, found that in polymerase chain reaction (PCR) surveys, V. ceranae was more common than V. apis ⁵.

Diagnosing Vairimorpha infections relies on microscopy, which allows beekeepers to quantify the spores. These spores represent the mature, environmentally resistant stage of the parasite, so spore counts provide an indirect measure of infection intensity. However, because the spores of V. ceranae and V. apis are difficult to distinguish, species-level identification requires polymerase chain reaction (PCR) to detect genetic differences between the microsporidia ².

Seasonal monitoring is essential because Vairimorpha levels fluctuate throughout the year. In Nova Scotia, McCallum et al. (2020) have shown that spore loads spike in May, then drop through the summer, with a smaller increase in spore loads in the fall ³. In Ontario, Emsen et al. (2020) have shown that infection intensity and prevalence of V. ceranae are highest in spring and summer seasons, and slightly lower in the fall ⁷. These seasonal trends emphasize the value of spring and fall testing for providing meaningful information on spore counts. 

Understanding the treatment of this disease is essential, like how fumagillin works and when it is most effective, when making management decisions. Next week’s blog will explore how Fumagillin interacts with the parasite inside the bee and how effective this is. 

 Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email attta@perennia.ca

References:

1. Sammataro, D. and Avitabile, A. 2021. A Beekeeper’s Handbook: Fifth Edition. Cornell University Press. 
2. Pernal, S.F. and Clay, H. 2013. Honey Bee Diseases & Pests, Third Edition. Canadian Association of Professional Apiculturists, Beaverlodge, AB, Canada, 68 pp. 
3. McCallum, R., Olmstead, S., Shaw, J. and Glasgow, K., 2020. Evaluating efficacy of Fumagilin-B® against nosemosis and tracking seasonal trends of Nosema spp. in Nova Scotia honey bee colonies. Journal of Apicultural Science, 64(2), pp.277-286.
4. Bojko, J., Becnel, J., Bessette, E., Edwards, S., Gao, J., Huang, W.F., Katanić, N., Khalaf, A., Li, T., Snow, J.W. and Solter, L.F., 2025. Nosema or Vairimorpha: genomic/proteomic support to a complex socio-economic issue rooted in taxonomic change. Journal of Invertebrate Pathology, 212, p.108376. 
5. McCallum, R., Olmstead, S., Shaw, J. and Glasgow, K., 2020. Evaluating efficacy of Fumagilin-B® against nosemosis and tracking seasonal trends of Nosema spp. in Nova Scotia honey bee colonies. Journal of Apicultural Science, 64(2), pp.277-286.
6. Emsen, B., Guzman-Novoa, E., Hamiduzzaman, M.M., Eccles, L., Lacey, B., Ruiz-Pérez, R.A. and Nasr, M., 2016. Higher prevalence and levels of Nosema ceranae than Nosema apis infections in Canadian honey bee colonies. Parasitology research, 115(1), pp.175-181.
7. Emsen, B., De la Mora, A., Lacey, B., Eccles, L., Kelly, P.G., Medina-Flores, C.A., Petukhova, T., Morfin, N. and Guzman-Novoa, E., 2020. Seasonality of Nosema ceranae infections and their relationship with honey bee populations, food stores, and survivorship in a North American region. Veterinary sciences, 7(3), p.131.

Now that some common pests and diseases have been identified and there is a better understanding of how some of these live and spread within a honey bee hive, it is time to apply some practices to effectively suppress the issue or prevent future infections. This week’s blog will discuss prevention and treatment, with a focus on integrated pest management (IPM), to ensure the honey bee brood is healthy and strong.

It Takes a Village to Raise Brood - Part 3

Stressors to honey bees can have a negative synergistic effect with pests and diseases, resulting in their introduction or spread in honey bee colonies. These stressors include, but are not limited to, old or unhealthy queens, food shortages, unfavorable environmental conditions, or even poisoning. These issues, along with pest and disease pressure, can be reduced with an integrated pest management (IPM) approach. An IPM approach includes cultural, physical, biological, and chemical control measures. The most effective IPM plan uses a variety of these measures together.

Selecting honey bee races that show better hygienic behavior to improve resistance to pests and diseases, rotating frames to reduce pests and disease presence, identifying early signs of pests and diseases, ensuring apiary biosecurity, and preventing robbing and drifting are preventative measures that can be used for most pests and diseases. For more information on seasonal best management practices, please check out ATTTA’s spring, summer, and fall management factsheets, as well as the comb rotation factsheet. Following are some IPM practices that are used, in addition to these preventative measures, to control some common pests and diseases in honey bees.

American Foulbrood (AFB)

Apiary hygiene, early detection, and prompt action are cultural control methods used to stop the spread of AFB. When a colony is suspected or identified to have AFB, it must be reported by law to the appropriated authorities, usually your provincial apiarist. Unfortunately, due to the high risks of AFB, the colonies and hive equipment must be destroyed. This is the only physical control method for AFB. Metaphylactic use of oxytetracycline (OTC) is the only permissible chemical control for managing AFB.  This would be done in consultation with a veterinarian through a Veterinary Client Patient Relationship

European Foulbrood (EFB)

A useful cultural control for EFB is ensuring that larval feeding is adequate. Supplemental feeding of sugar syrup and pollen substitute can be used to ensure adequate amounts of feed. This may also ensure that the brood nest and nurse bee numbers are proportional for feeding brood. If the infection is not severe, it is possible for the honey bee colony to suppress EFB on its own. If the infection is severe, then colonies and equipment eradication may be used as a physical control method. Antibiotics, such as OTC, may be used as a chemical control method, again in consultation with a veterinarian.

Chalkbrood

Maintaining a strong healthy honey bee colony can be an effective cultural control method for suppressing chalkbrood infections. Supplemental feeding when nectar and pollen is low, maintaining proper ventilation so there are no fluctuations in moisture and temperature, and requeening can be used to maintain strong healthy colonies.

Varroa mite on honey bee brood (OrkinCanada©2023)

Varroa Mites

Beekeepers can create a break in the brood rearing cycle as a cultural method to slow the growth of varroa mite populations. Physical methods, such as screen bottom boards, can be used to directly remove varroa mites. Varroa mites are highly attracted to drone cells, so plastic foundations of drone cells can be placed in a hive, to trap varroa mites, and the frame can be removed, when capped, and frozen to kill any varroa mites. Synthetic and organic miticides are used as a chemical method to suppress varroa mites. Label instructions must be followed to ensure that the colony is properly treated, to prevent the accumulation of chemicals in honey bee hives, and to prevent potential resistance in varroa mite populations. Please check out ATTTA’s factsheet on varroa mite management options for Atlantic Canada for more treatment options and information on how to apply treatments.

Written by John MacDonald, ATTTA Seasonal Apiculturist - johnmacdonald@perennia.ca

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

References

Pernal, S.F. and Clay, H. (eds). 2013. Honey bee diseases and pests 3^rd Edition. Canadian Association Professional Apiculturists, Beaverlodge, AB, Canada. 

 

Last week’s blog was about identifying any potential issues in brood and attempting to diagnose the underlying pathology. The next step towards prevention and treatment is an understanding of the spread of each pest or disease. For successful prevention or suppression, it is important to know the aspects of the life cycles of pests and diseases and be able to apply the best integrated pest management (IPM) practices. This week will discuss how these pests and diseases spread in honey bee colonies to set the groundwork for a discussion of management practices.

It Takes a Village to Raise Brood - Part 2

American Foulbrood (AFB)

The usual route of contamination is that bee larvae consume bacterial spores in contaminated food. The bees are most susceptible when less than 24 hours old, but after 48 hours they become resistant to infection. The bacteria multiply in the midgut of larvae and burst into the haemocoel killing the developing bee. AFB is usually spread through housecleaning practices of the honey bees; bees contaminate their mouth parts and digestive tracts and pass the bacteria along to larva by cleaning cells or feeding. AFB spores can live in larval food, soil, or beekeeping equipment for decades, so honey bees and hives must be destroyed when there is an AFB infection.

European Foulbrood (EFB)

The usual route of contamination, similar to AFB, is that the bee larvae consume bacteria in contaminated food. The bees are most susceptible when less than 24 hours old, but after 72 hours they become resistant to infection. The bacteria multiply in the midgut of larvae and compete for food. EFB is also usually spread through housecleaning practices by honey bees. Typically, symptoms of EFB do not show when there is an abundant supply of food, but bacteria remain in the colony, within equipment and adult bees.

Brood infected with European Foulbrood (BeeInformed©2013)

Chalkbrood

This infects bee larvae and pupae by ingestion of fungal spores in contaminated food as well. The range of susceptibility for the Larvae is from 1 - 5.5 days old but they are most at risk at 3-4 days. Larvae become mummified in 2-3 days after infection, and the fungal mycelium completely replaces the bee. Spores can reside in hives without showing any symptoms but grow under certain conditions, such as high moisture or low temperatures. Spores are spread by nurse bees from stored pollen or housekeeping activities.

Varroa mites

These ectoparasites enter the cells just prior to capping and feed on larvae and, subsequently adult bees. Their reproductive cycle is carried out in brood cells. The female mites detach from bees when ready to reproduce and enter brood cells. When brood is abundant, up to 80% of varroa mites can be found in brood cells. The varroa mites are immersed in the bee’s food, but soon start to feed on the larvae and lay eggs. One male and multiple female mites are laid, and they reproduce inside the cell, before the bee emerges. A maximum of 3 mites can be produced in a worker bee cell and 5 mites for a drone cell. The female mites then attach to an adult bee to feed until reproduction.

A better understanding of how pests and diseases spread in a honey bee colony can help in applying the most effective management practices. Next week’s blog will briefly discuss prevention and treatment with a focus on Integrated Pest Management.

 

Written by John MacDonald, ATTTA Seasonal Apiculturist johnmacdonald@perennia.ca

 

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

 

References

Pernal, S.F. and Clay, H. (eds). 2013. Honey bee diseases and pests 3^rd Edition. Canadian Association Professional Apiculturists, Beaverlodge, AB, Canada.

When most people think of honey bees, they think about the adult bee, but the brood deserves much more attention. Honey bees have certain behaviors that are necessary to keep the brood alive, such as feeding the brood and cleaning the cells after the brood have emerged, but there are certain pests and diseases that effect the brood, where human intervention is needed to prevent colony losses. The beekeeper can help the colony by routine inspections for identification of issues and using an integrated pest management (IPM) plan. Researchers can also help identify the most effective management practices to use.

It Takes a Village to Raise Brood

The honey bee queen lays eggs upright, the eggs soon lean over, and after 3 days hatch into larvae. The larvae start out curled up at the bottom of the cell and consume food from the bottom of cell or directly from nurse bees; the larvae molt 4 times throughout this stage. Healthy larvae should appear full bodied, firm, with distinct segmentation, pearly white, and moist. Queen and worker bee cells are capped after approximately 8 days, and drone cells are capped at approximately 10 days. The larvae spin a cocoon on the walls of the cell and pupate after the 5th molt. From pupal form, the bees molt again to become adult bees. Development from egg to adult bee typically takes 16 days for queen bees, 21 days for worker bees, and 24 days for drone bees.

A honey bee colony needs adequate amounts of honey and pollen to raise brood, and if a colony is low on reserves, it will reduce production or even cannibalize its brood. A healthy brood pattern is consistent with larvae of similar size, with the eggs laid in concentric bands from the center of a frame, with each band around the same age. Issues can be identified by any changes to the appearance of the brood within the cell and the pattern of the brood throughout the hive. There are also many pests and diseases that affect the brood and rely on the brood cycle for reproduction. There are certain symptoms of pests and diseases that can be observed and techniques that can be used to properly identify a pest or disease. The following are a few brood diseases and ways to identify within the bee colony.

(Hive inspection, ATTTA©2022)

American Foulbrood (AFB)

Examining the brood can help identify AFB. If brood is discolored and dying, and cappings are perforated with small holes and sunken with greasy appearance, the colony may have AFB, but these symptoms can also be seen with other diseases. Better ways to identify AFB are by finding a brown/black flat scale that adheres tightly to cell wall and is difficult to remove. AFB is also identified by using the ropiness test. The ropiness test is done by stirring the diseased brood tissue, in the cell, with a stick and removing it slowly, if there is a glue-like consistency that strings out ~2cm, then the colony likely has AFB. Samples can also be sent into AFB programs for laboratory diagnosis. If AFB is suspected or identified, it must be reported by law to the appropriated authorities, usually your provincial apiarist.

European Foulbrood (EFB)

Infection of EFB is not easily distinguishable. The midgut of the honey bee larvae can be seen through its translucent body. EFB can be seen as a chalky white mass in the midgut. When food is abundant infected larvae emerge as adults but their cappings are darkened by bacteria and adults are smaller and lighter in color. If the larvae are not overfed, they die of starvation usually before the cell is capped. The larvae turn yellow/brown and can be seen twisted around cell wall, lying across the mouth of the cell, or stretched out from the mouth to the base of the cell. The larvae color darkens to brown and dries into a scale that is rubbery and easy to remove. When using the ropiness test, EFB shows a watery consistency in the diseased brood.

Chalkbrood

Infection of chalkbrood is easy to identify. The infected brood can be seen as black, grey, or white mummies on bottom board, in pin-holed cells, or outside the hive entrance. In the cell, the anterior part of the bee that is facing up is usually dry and yellow.

Varroa mites

An infestation of varroa mites can lead to symptoms of spotty bee brood patterns, and deformed adult bees, due to increased levels of viruses vectored by varroa mites feeding on the honey bees. Visual inspections are usually insufficient to detect levels of varroa that are damaging. Varroa mites are usually in the capped cells or on the bottom of the abdomen of adult bees, so they are difficult to spot. The best way to identify a varroa infestation is by doing varroa sampling by using an alcohol wash, ether roll, or installing a sticky board in a screened bottom board. More information on testing for Varroa and economic thresholds can be found in the Summer Disease and Pest Monitoring in Honey Bees Factsheet by ATTTA.

Next week’s blog will discuss the life cycles of the pests and diseases mentioned above.

Written by John MacDonald, ATTTA Seasonal Apiculturist - johnmacdonald@perennia.ca

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

References
Pernal, S.F. and Clay, H. (eds). 2013. Honey bee diseases and pests 3^rd Edition. Canadian Association Professional Apiculturists, Beaverlodge, AB, Canada.

Vairamorpha: A New Name for a Familiar Threat

Nosema disease refers to an obligate intracellular eukaryotic parasite that affects adult honey bees. It is caused by the pathogens Vairimorpha apis and Vairimorpha cerenae, previously known as Nosema apis and Nosema ceranae. In this week’s blog, we will be discussing how to accurately identify a clinical infection of Nosema in your honey bee colony.

Vairimorpha: A New Name for a Familiar Threat

Varimorpha spores are often present in honey bees at subclinical levels but when the population of spores exceeds a certain amount, the infected colony will begin to show disease signs. The disease disrupts the bees digestive system and they may succumb to premature death. Reduced worker longevity impacts foraging and subsequent honey yield.  Also, the inhibition of pollen digestion impacts the development of the hypopharyngeal gland in worker bees such that brood rearing declines. These are only a few symptoms of infection. Unfortunately, there are no observable symptoms of a clinical Variamorpha infection that can provide a clear diagnosis.

The only way to diagnose Variamorpha infection is by observing a sample of suspected bee’s gut content under a microscope. Vairimorpha spores live in the midgut of adult honey bees. Adult bees inadvertently ingest spores through contact with their environment or other honey bees. Once ingested, the spores infect the epithelial cells of the honey bee midgut and begin to germinate rapidly until there are so many that the cell ruptures, releasing spores into the digestive system. As such, accurate identification of a Vairimorpha infection requires observing, via microscopy, the midgut content of worker honey bees. 

Vairimorpha spores observed under a compound microscope at 400x magnification. See examples of egg-shaped spores circled in blue. (ATTTA©2022). 

To do this, a sample of bees must be collected, crushed, and observed under a microscope. Older foraging bees are best because they will have higher spore loads than younger bees. Collect a sample of 30 foraging worker bees, found near the bottom board or amongst honey frames, and kill them by freezing. Then, mix the sample of bees with 30 mL of water, to have 1 mL of water per bee, and crush the bees to create a slurry. This can be done with a mortar and pestle or in a sealed plastic bag with a rolling pin. Vairimorpha spores will be within this slurry and can be observed under a microscope.

A standard haemocytometer, or cell counting chamber, will make it possible to quantify the number of spores per bee in the sample. A haemocytometer has two wells per chamber which each contain a known volume of liquid (100nl). Using an eyedropper, obtain a sample of the bee-water slurry and drop it such that the liquid will fill the wells. A haemocytometer also has gridlines of known area. To quantify the number of spores in the slurry, count the number of spores in five of the twenty-five grid squares using 400x magnification. Standard procedure is to count the four corners and middle square, in each of the two hemocytometer wells (Cantwell 1970; Williams et al. 2011). Then, calculations must be done to find the number of spores per bee in the sample. First, add the total number of spores counted in each of the wells together and divide by two to find the average number of spores per well. Multiply this number by 5 to get the number of spores per well.  Multiply the average number of spores per well by 10 000 to provide the average number of spores per ml which equates to number of spores per bee. Presently, the economic treatment threshold is one million spores per bee (Williams et al. 2011). In this situation, an integrated pest management approach would suggest that chemical treatment be done to address the high levels of spores in the colony. Presently, Fumagilin-B is the only registered treatment of Vairimorpha in Canada and should be applied according to label instructions.

Vairimorpha infestations often accumulate over the winter and are highest in the spring. If overwintered colonies are weak and sickly in the spring, be prepared to consider the possibility of a Vairimorpha infection. ATTTA is equipped and happy to test your samples. Atlantic beekeepers can reach out using the contact information below for more information or to arrange testing!

References

Cantwell, G. E. 1970. Standard methods for counting Nosema spores. American Bee Journal 110: 52-54.

Williams, G., Shutler, R., Little, D., Burgher-Maclellan, C., & Rogers, M. 2011. The microsporidian Nosema ceranae, the antibiotic Fumagilin-B®, and Western honey bee (Apis mellifera) colony strength. Apidologie 42: 15–22.

 Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca