Going Viral by Alan Wade

There are many honey bee viruses though a number are conspicuously absent from Australia. It is imperative that we keep a host of exotic bee viruses away from our shores, not least the destructive deformed wing virus. Not all viruses cause symptomatic disease and some, brought home by foragers visiting flowers in the meadow, are readily shared between flies, butterflies and solitary bees as well as nectar foraging wasps (Johnson, 2012; Cilia et al., 2022).

What are viruses?

Viruses comprise a strand of RNA or DNA (Grice, 2026) sheathed in protein envelope. To say that they are common is an understatement. It seems likely that there are an an outstanding number of them, ~10³¹ on planet Earth (Mushegian, 2020). National Geographic suggests that their number easily dwarfs the number of billions of stars (10²²-10²⁴) in the many billions of galaxies festooning the universe. Wikipedia (2026) provides a concise definition of what viruses constitute:

A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.

My early beekeeping experience of ‘virus problems’ is limited to observing spotty brood and discovering that the brood patch was sorely afflicted by sacbrood (SBV). The sacbrood virus present in their millions as soggy pouches when you poke the larval remains of a single sick cell with a matchstick.

The until now more consequential fungal chalkbrood, had not turned up locally until about 2001. The solution to both, chalkbrood and sacbrood, is to avoid damp conditions by locating hives in the sun, to requeen, to that stores are up to scratch and to toss out infected gear. Then other bee maladies arrived on our shores (Table 1). Small hive beetle turned up in 2002 while Black queen cell virus, a serious disease of bees – not just of queen bees – was only recognised as a problem in Australia in 1993.

So why, suddenly, do viruses loom so large and seem likely to change the face of beekeeping? The game has changed with the arrival of parasitic mites and nosema. They do enough damage in their own right but we now know that they vector viruses in novel ways: viruses have become deadly and virulent.

Pest or disease	Causative agent	Incursion date	Notes
American Foulbrood	Paenibacillus larvae	Incursion date not known but likely spreading.	Differentiated from EFB in 1906. Absent from NT and Kangaroo Island (SA)
Sacbrood virus (SBV)	Sacbrood virus genotype AM (genotype AC less lethal)	~1872 (first characterised in US but widespread)	Separate genotypes for Apis mellifera and Apis cerana
Braula fly	Braula coeca	1932 (Tas)	Detected in Vic 2023
Cane toad	Rhinella marina	1935 (Qld)	Now widespread in tropics
European or German wasp	Vespula germanica	1959 (Tas)	Now widespread in SE Australia, southern South Australia and SW Western Australia. Common wasp Vespula vulgaris also in Victoria
Nosema (Apis mellifera origin)	Nosema apis	1961 (first isolated in SA)	Isolated in UK in 1955Nosema cerana now widespread; Nosema neumanni now most common in Uganda.
Black queen cell virus (BQCV)	Black queen cell virus	1974 (first characterised in UK)	Widely known to kill queen larvae in Australia in 1993
European Foulbrood	Mellisococcus pluton	1977(NSW, Vic, SA)	Absent from WA and NT
Buff-tailed Bumblebee	Bombus terrestris	1992 (Tas)	1909 attempt to introduce bumble bees to Tas failed.
Chalkbrood	Ascosphaera apis	1993 (Qld)	Spread to all states by 2001
Small hive beetle	Aethina tumida	2002 (NSW)	Was absent from WA until a load of irradiated beehives with shb was moved to the Kimberly
Asian honey bee	Apis cerana	2007 (Qld)	Established near Cairns. Separate incursion to Brisbane with accompanying Varroa jacobsoni March 2024
Nosema (Apis cerana origin)	Nosema ceranae	2009	First isolated in Taiwan in 1996
Israeli acute paralysis virus (IAPV)	Israeli acute paralysis virus (IAPV)	2017 (identified by Roberts et al)
Lake Sinai virus (LSV1 and LSV2)	Lake Sinai virus	2017 (identified by Roberts et al)
Varroa mites	Varroa destructor	22 June 2022 (NSW)	Detected at Port of Newcastle, NSW (previous incursions at Townsville 2016, 2019 and 2020)›
Small red dwarf honey bee	Apis florea(Euvarroa sinhai)	6 July 2023 (WA)	Burra Peninsula near Karratha WA
Varroa mite	Varroa jacobsoni	27 February 2024	News report of PNG Varroa import. Presently limited to Australian islands in the Torres Strait

Table 1        Arrival of honey bee diseased and viruses circulating in Australia.

Viruses are parasites of all life forms. Only a limited number plague our bees but varroa and the protists will make even those that do more lethal agents even if deformed wing virus – especially the B strain – never lands in our shores. Key and common pathogenic viruses amplified by the likes of Varroa destructor and Tropilaelaps mercedesae include Black queen cell virus (BQCV), Chronic bee paralysis virus (CBPV), Israeli acute paralysis virus (IAPV), Lake Sinai virus (LSV1 and LSV2), Sacbrood virus (SBV). Pioneer researchers at Rothamsted Agricultural Research Station in the United Kingdom (Allen and Ball, 1996; see also Bailey, Ball and Woods, 1976; Bailey and Ball 1978; Ball, 2004) identified a total of 18 viruses including those from Apis cerana more than a quarter of a century ago. Those honey commonly found now are listed in Table 2.

Family	Virus	Target stage/caste of bees	Australia
Dicistroviridae	Acute bee paralysis virus (ABPV)	Brood, workers, drones
	Israeli acute bee paralysis virus (IAPV)	Eggs, larvae, pupae, workers, drones, queens	✔
	Kashmir bee virus (KBV)	Eggs, larvae, pupae, workers, drones, queens
	Apis dicistrovirus (ADV)	Workers, drones
	Aphid lethal paralysis virus (ALPV)	Workers, drones
	Big Sioux River Virus (BSRV)	Workers, drones
	Black queen cell virus (BQCV)	Larvae, pupae, workers, drones, queens	✔
Unclassified	Chronic bee paralysis virus (CBPV)	Workers, drones, queens
Iflaviridae	Deformed wing virus (DWV) (A, B and C)	Eggs, larvae, pupae, workers, drones, queens	✖
	Sacbrood virus (SBV)	Brood, workers, drones	✔
	Slow bee paralysis virus (SBPV)	Larvae, workers, drones	✖
Unclassified	Lake Sinai virus (LSV)	Workers, drones	✔
Tymovinidae	Bee macula-like virus (BeeMLV)	Pupae, workers
	Bee macula-like virus-2 (BeeMLV-2)	Pupae, workers
	Varroa tymo-like virus (VTLV)	Workers, drones
Unclassified	Cloudy wing virus (CWV)	Workers, drones
Nodavindae	Apis noda-like virus	Workers, drones
	Apis nora virus (ANV)	Workers
Rhabdovinidae	Apis rhabdovirus -1/ Bee rhabdovirus-1 (ARV-1/ BRV-1)	Workers, drones	(ARV1)✔
	Apis rhabdovirus -2 (ARV-2)	Workers, drones	(ARV2)✔
Bunyavindae	Apis bunya virus-1 (ABV-1)	Workers, drones
	Apis bunya virus-2 (ABV-2)
Flaviviridae	Apis flavivirus (AFV)	Workers, drones
Picorna-like	Berkeley bee picora-like virus (BBPV)	Workers, drones
Secoviridae	Tobacco ring spot Virus (TRSV)	Workers, drones
Secoviridae	Seco-like virus	Workers
Iflaviridae	Moku virus	Workers
Orthomyxoviridae	Varroa Oorthomyxovirus-1 (VOV-1)	Workers
Partitiviridae	Partiti-like virus	Workers
Unclassified	Bee Y virus	Workers, drones
	Bee X virus	Workers, drones
	Egypt bee virus	Workers, drones
	Arkansas bee virus (ABV)	Workers, drones
Iridoviridae	Apis iridovirus (AIV)	Workers, drones
Unclassified	Apis mellifera filamentous virus (AmMFV)	Workers, drones
Circovindae	Circo-1, Circo-2	Workers

Table 2       Phylogenetic origin of respective viruses and the target stage/caste of bees. Source: Gajda, Mazur and Bober (2021). These authors identify 36 viruses though others, Asian sacbrood virus and Apis iridescent virus have been isolated from Apis cerana, Apis florea and Apis dorsata.

While over three dozen viruses were known by 1921, more novel viruses are now routinely identified using molecular tools. Remnant, Holmes and Roberts (2024) outline honey bee viruses of concern in Australia (Table 3) citing occasional outbreaks of disease in the absence of Varroa. An obvious example is sacbrood virus for which the traditional remedies are good nutrition, optimising hive conditions and requeening. They signal that, with active transmission by Varroa, three virus complexes: Deformed wing virus (DWV-A, DWV-B) (Genersch and Aubert (2010); the Acute, Israeli and Kashmir bee paralysis viruses (ABPV, IAPV and KBV); and Slow bee paralysis virus strains (SBPV) can cause major problems at the colony level (de Miranda et al., 2012; McMenamin and Genersch, 2015). The most significant problems are those associated with up to a millionfold increase in Deformed wing virus levels, also evolved to be more pathogenic (Neumann et al., 2012). Other viruses such as Tobacco ringspot virus (TRSV), apart from being a serious plant virus, also shortens the life of bees and affects their wings.

Honey Bee Virus	Effect	Varroa Associated	Presence in Australia
Acute bee paralysis virus (ABPV)	Causes pupal paralysis and mortality in association with varroa	✔	✖
Apis Rhabdovirus-1 and -2 (ARV-1, ARV-2)	Asymptomatic	✔	✔
Black queen cell virus (BQCV)	Causes queen larval/pupal mortality	✖	✔
Chronic bee paralysis virus (CBPV)	Can cause large worker bee losses. Infected bees can be paralysed and appear black, hairless and greasy with shortened abdomens	✖	✔
Deformed wing virus A (DWV-A)	Inhibits pupal development and reduces lifespan of the emerging bee. Emerged bees can have deformed wings	✔	✖
Deformed wing virus B (DWV-B)	Inhibits pupal development and reduces lifespan of the emerging bee. Emerged bees can have deformed wings	✔	✖
Israeli acute paralysis virus (IAPV)	Causes pupal paralysis and mortality in association with varroa	✔	✔
Kashmir bee virus (KBV)	Causes pupal paralysis and mortality in association with varroa	✔	✔
Lake Sinai virus (LSV)	Infects adult bees and may reduce lifespan	✖	✔
Sacbrood virus (SBV)	Causes larval mortality	✖	✔
Slow bee paralysis virus (SBPV)	Causes pupal paralysis and mortality in association with varroa	✔	✖

Table 3        Honey bee viruses found in Australia.Source: Adapted from Remnant et al. (2024). Apis Rhabdovirus has been added as a known honey bee virus.

Can we rest on our laurels? Even in the absence of DWV, Remnant and coworkers suggest that Varroa may exacerbate Israeli acute paralysis virus (IAPV), Sacbrood virus (SBV) and Black queen cell virus (BQCV). It would be well to record Sacbrood virus levels (as the club already does in its Jerrabomberra apiary) to trigger a fuller alert to Varroa impact. This topic of how viruses affect bees is canvased by AgriFutures Varroa (2024).

In a wide ranging survey of viruses and associated bee pathogens Runckel and coworkers (2011) tracked their seasonal occurrence in hives being migrated for pollination services employing a genetic ‘Arthropod Pathogen Microarray’, a suite of polymerase chain reaction (PCR) tools. They routinely detected more than twenty nine viruses – several novel – as well as six pathogenic bacteria and six fungi and protists along with several parasitic mites and nematodes.

From a perspective of understanding which of the many viruses seriously impact on honey bee health, two considerations are important. The first of these is to pinpoint those viruses or their variants that actually affect honey bee health. That the mites and viruses can evolved in concert to become more damaging under the influence of chemical mite control is particularly unsettling. It is though we are deliberately painting ourselves into a corner, breeding bees totally dependent on treatments that are increasingly ineffectual. The current absence of Deformed wing virus in Australia as well as its absence from Papua New Guinea, The Solomons (Roberts, Anderson and Durr, 2017) and much of the Pacific suggests that the path to Varroa resistant bees may be smoother in our region than in Europe and North America. The second concern relates to how we might manage bees to minimise their impact. In this there is broad scope to optimise colony health.

In all we might envision viruses and parasites such as the phoretic mites and protists such as Vairimorpha ceranae and Lotmaria passim as a complex insect-microorganism ecosystem best controlled by effective quarantine measures and some measure of good apiary practice such as stringent mite management and good apiary hygiene.

A beginning only

There is a wealth of published information on honey bee viruses that this brief overview barely touches on. Here are a handful of readable reviews that provide a broader take on the insidious nature of bee viruses and in various measure signal how they can be well managed or at least better understood.

It would appear that Going Viral is more apt for beekeepers than it is for those who dabble in the dark arts of social media.

Apis Information Resource Center (accessed 19 September 2025). Viruses and honey bees, https://beekeep.info/apimondia-south-africa-2001/a-treatise-on-modern-honey-bee-management/managing-diseases-and-pests/viruses-and-honey-bees/

Chen, Y. (2011). Chapter 6 Viruses and viral diseases of the honey bee, Apis mellifera. In Recent Advances in Entomological Research  Liu, T. and Kang, L. (eds.). Molecular biology to Pest management, pp.105-120). Berlin, Heidelberg: Springer Berlin Heidelberg. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=Viruses+and+viral+diseases+of+the+honey+bee%2C+Apis+mellifera.&btnG=

Grozinger, C.M. and Flenniken, M.L. (2019). Bee viruses: Ecology, pathogenicity, and impacts. Annual Review of Entomology 64(1):205-226. https://par.nsf.gov/servlets/purl/10138592

Holmes, M.J., Gerdts, J.R., Grassl, J., Mikeheyev, A.S., Roberts, J.M.K., Remnant, E.J. and Chapman, N.C. (September 2023). Resilient beekeeping in the face of varroa. AgriFutures Australia publication no. 23-226, 153pp. https://agrifutures.com.au/wp-content/uploads/2024/01/23-226-resilient-beekeeping-in-the-face-of-varroa.pdf

Matusiewicz, M., Margas, E., Mazurek, M.P., Wesolowska, L., Belter, A. and Skupinska, M. (2016). Viral infections of Apis mellifera: Its importance, dynamics, diagnostics and treatment opportunities. BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology 97(3):211-225. https://pdfs.semanticscholar.org/a30e/084a7436a12dcc9fb2f7c60705568976ad1b.pdf

McMahon, D.P., Wilfert, L., Paxton, R.J. and Brown, M.J. (2018). Emerging viruses in bees: From molecules to ecology. Advances in Virus Research 101:251-291. https://www.sciencedirect.com/science/article/abs/pii/S0065352718300113

Tantillo, G., Bottaro, M., Di Pinto, A., Martella, V., Di Pinto, P. and Terio, V. (2015). Virus infections of honeybees Apis mellifera. Italian Journal of Food Safety 4(3):5364. https://pmc.ncbi.nlm.nih.gov/articles/PMC5076640/ https://www.wellesu.com/10.4081/ijfs.2015.5364

Schouten, C. and Remnant, E. (28 January 2025). Project Varroa: Better understanding beekeeper and industry-wide challenges in managing varroa. https://honeybee.org.au/virus-update-for-australian-beekeepers-southern-cross-university/

Ullah, A., Gajger, I.T., Majoros, A., Dar, S.A., Khan, S., Shah, A.H., Khabir, M.N., Hussain, R., Khan, H.U., Hameed, M. and Anjum, S.I. (2021). Viral impacts on honey bee populations: A review. Saudi Journal of Biological Sciences 28(1):523-530. https://www.sciencedirect.com/science/article/pii/S1319562X20305246

Wei, R., Cao, L., Feng, Y., Chen, Y., Chen, G. and Zheng, H. (2022). Sacbrood virus: A growing threat to honeybees and wild pollinators. Viruses 14(9):1871. https://www.mdpi.com/1999-4915/14/9/1871

Readings

AgriFutures Varroa – bee health factsheet (2024). Agrifutures Australia. https://honeybee.org.au/wp-content/uploads/2024/05/Resilient-Beekeeping-Bee-Health-Factsheet.pdf

Allen, M. and Ball, B. (1996). The incidence and world distribution of honey bee viruses. Bee World 73(3):141-162. https://doi.org/10.1080/0005772X.1996.11099306

Bailey, L., Ball, B.V. and Woods, R.D. (1976). An Iridovirus from bees. Journal of General Virology 31(3):459-461. https://doi:10.1099/0022-1317-31-3-459

Bailey, L. and Ball, B.V. (1978). Apis iridescent virus and clustering disease of Apis cerana. Journal of Invertebrate Pathology 31(3):368-371. https://sci-hub.sidesgame.com/10.1016/0022-2011(78)90231-8

Ball, B.V. (2004). The trouble with viruses. Bee World 85(2):25. https://sci-hub.sidesgame.com/10.1080/0005772x.2004.11099613

Cilia, G., Flaminio, S., Zavatta, L., Ranalli, R., Quaranta, M., Bortolotti, L. and Nanetti, A. (2022). Occurrence of honey bee (Apis mellifera L.) pathogens in wild pollinators in northern Italy. Frontiers in Cellular and Infection Microbiology 12:907489. https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.907489/full https://pmc.ncbi.nlm.nih.gov/articles/PMC9280159/

de Miranda, J.R., Gauthier, L., Ribière, M. and Chen, Y.P. (2012). Honey bee viruses and their effect on bee and colony health. Honey Bee Colony Health: Challenges and Sustainable Solutions, Chapter 8, pp.71-102.

Gajda, A., Mazur, E. and Bober, A. (May 2021). Bee keepers’ guide to honey bee viruses. Bee Culture. https://beeculture.com/bee-keepers-guide-to-honey-bee-viruses/

Genersch, E. and Aubert, M. (2010). Emerging and re-emerging viruses of the honey bee (Apis mellifera L.). Veterinary Research 41(6):54. https://pmc.ncbi.nlm.nih.gov/articles/PMC2883145/pdf/vetres-41-54.pdf

Grice, K. (17 March 2026). All 5 fundamental units of life’s genetic code were just discovered in an asteroid sample. The Conversation. https://theconversation.com/all-5-fundamental-units-of-lifes-genetic-code-were-just-discovered-in-an-asteroid-sample-278099

Johnson, B.R. (2020). Honey Bee Biology. Princeton University Press.

McMenamin, A.J. and Genersch, E. (2015). Honey bee colony losses and associated viruses. Current Opinion in Insect Science 8:121-129. https://sci-hub.usualwant.com/10.1016/j.cois.2015.01.015

Mushegian, A.R. (2020). Are there 10³¹ virus particles on earth, or more, or fewer?. Journal of bacteriology 202(9):1110-1128. https://journals.asm.org/doi/full/10.1128/jb.00052-20

Neumann, P., Yañez, O., Fries, I. and de Miranda, J.R. (2012). Varroa invasion and virus adaptation. Trends in Parasitology 28(9):353-354. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=Varroa+invasion+and+virus+adaptation&btnG=

Remnant, E., Holmes, M. and Roberts, J. (20 November 2024). Varroa and viruses. Professional Beekeepers. https://extensionaus.com.au/professionalbeekeepers/varroa-and-viruses/

Roberts, J.M.K., Anderson, D.L. and Durr, P.A. (2017). Absence of deformed wing virus and Varroa destructor in Australia provides unique perspectives on honeybee viral landscapes and colony losses. Scientific Reports 7(1):6925. https://doi:10.1038/s41598-017-07290-w

Runckel, C., Flenniken, M.L., Engel, J.C., Ruby, J.G., Ganem, D., Andino, R. and DeRisi, J.L. (2011). Temporal analysis of the honey bee microbiome reveals four novel viruses and seasonal prevalence of known viruses, Nosema, and Crithidia. PloS One 6(6):e20656. https://pmc.ncbi.nlm.nih.gov/articles/PMC3110205/ https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0020656&type=printable

Wikipedia (Accessed 15 March 2026). Virus. https