There is a strong temptation for new beekeepers to worry that their hive has every bee disease known to humans and then some. The truth of the matter is that honey bees are usually pretty healthy. You are likely to encounter the Varroa mite, so we encourage you to know about them and their life cycle; American Foul Brood is a contagious and reportable bee disease, so you should 1) know that it exists, and 2) know a bit about the symptoms, and 3) know that most beekeepers have never seen it. If you are starting with bees, it is far more essential to know what healthy brood and bees look like. If you think something is off, review the pests and diseases listed here - we’ve tried to include most and provide Maine-specific information where applicable.
This is what healthy looks like:
Randy Oliver - scientifcbeekeeping.com - used with permission
Larvae floating in pools of jelly (food).
licensed by Shutterstock
Capped worker brood surrounded by eggs and larvae.
licensed by Shutterstock
A worker honey bee.
Honey Bee Diseases and Pests
Diseases can be categorized into two classes: those that affect developing bees and those that affect adult bees.
American Foulbrood
Paenibacillus larvae
Randy Oliver - scientifcbeekeeping.com
Brood Disease
American Foul Brood (AFB) is a contagious bacterial disease, the spores of which remain infectious for over 50 years. There are a handful of cases in Maine each year now, primarily attributed to the reuse of long-stored but uninspected equipment. It is a disease that formerly had a much larger incidence in Maine, but now there are usually between two and four outbreaks per year. The State Apiarists (formerly Tony Jadzack and now Jen Lund) deserve much credit for reducing the number of incidents that have taken AFB from the feared category and placed it in the group that requires vigilance and recognition of symptoms.
Randy Oliver - scientifcbeekeeping.com
Randy Oliver - scientifcbeekeeping.com
PennState Extension website on American Foul Brood AMAZING PICTURES OF AFB IN VARIOUS STAGES BY EAS MASTER BEEKEEPER STEVEN REPASKY
Bee Aware (Australia) website on American Foul Brood
Honey Bee Health Coalition - PDF - IDENTIFYING AND MITIGATING FOULBROOD IN HONEY BEE COLONIES AND REDUCING THE USE OF ANTIBIOTICS
Oregon State University Extension - Video - Diagnosing American Foulbrood in Honey Bee Colonies - 10:39
USDA ARS - American Foulbrood Factsheet
In Maine, hives infected with American Foulbrood Disease, after a confirming laboratory test, must be destroyed. (both bees and woodenware)
Chalkbrood
Ascophaera Apis
Randy Oliver - scientifcbeekeeping.com
Brood Disease
Chalkbrood is a common issue in Maine. It is a mostly seasonal fungal disease that is related to colony stress. It is not usually fatal to the colony. There is no treatment. Some species of native bees also get Chalkbrood (Ascophera spp).
The Animal and Plant Health Agency (APHA), Crown Copyright
Honey Bee Suite - blog post on Chalkbrood - Chalkbrood disease of honey bees.
USDA ARS in Beltsville, MD - Web page on Chalkbrood.
Bee Health Extension - Web page on Chalkbrood.
Inside the Hive.TV - video - The Fungus Among Us: The Bee Disease Making Beekeepers Fight!
Texas Apiary Inspection Service - Web page on Chalkbrood.
European Foulbrood
Melissococcus plutonius
Randy Oliver - scientifcbeekeeping.com
Brood Disease
Often called by its initials, EFB, is common in Maine, While it is a bacterial disease, it is one that does not produce spores.
The Animal and Plant Health Agency (APHA), Crown Copyright
Bee Health (eXtension.org)
Bee Health Extension - Web page on European Foulbrood.
Sacbrood Virus
genus Iflavus
Randy Oliver - scientifcbeekeeping.com
primarily a Brood Disease, also impacts young adult bees
Sacbrod virus is fairly rare, but not unheard of in Maine.
The Animal and Plant Health Agency (APHA), Crown Copyright
Bee Health (eXtension.org)
Bee Aware - Web page on Sacbrood.
Stonebrood
Scientific Name
Photo Credit
Brood Disease
A regulated disease in Maine that must be reported. Rare in Maine.
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Linked articles.
”Africanized” honey bees
Hybrid of Apis meliffera scutellata (sometimes called The East African lowland honey bee) and other Apis meliffera subspecies.
By Ktr101 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=47420143
Pest
Very occasionally unintentionally imported into Maine and not believed to survive Maine winters. A regulated “pest” that must be reported. May be as much as 10% smaller than managed honey bees, but otherwise not visually discernible.
By Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org - CC BY 3.0 us
Rudolph Steenkamp via iNaturalist, some rights reserved (CC BY-NC)
Wikipedia webpage on Africanized Honeybees
Asian honey bee
Apis cerana a/k/a “The Eastern Honey Bee”
iNaturalist user Sunnetchan CC BY-NC-ND
Pest
Not known to be in Maine. A regulated “pest” that must be reported.
Licensed by Shutterstock
Photo Credit
iNaturalist species web page on Apis cerana
PDF of article - Grindrod, I., Martin, S.J. Varroa resistance in Apis cerana: a review. Apidologie 54, 14 (2023)
Black Bear
Ursus americanus
Licensed by Shutterstock
Pest
Common in Maine. Bears sense of smell is excellent and hives offer both protein (bees & bee larvae) and carbohydrate (honey). Electric Fences are often used as a psychological barrier to keep bears out of apiaries.
USFW - at Moosehorn National Wildlife Refuge, Maine
Licensed by Alamy
International Association for Bear Research and Management - website for Black Bears - (includes Black Bear biology)
PDF - Maine F&W - Keeping Black Bears Out Of Beehives.
Vermont Fish and Wildlife - webpage - Protect Your Property With A Zap.
North American Bear Center - webpage - What Do Bears Like To Eat In A Beehive?
ScienceABC - webpage - Do Bears Really Like Honey?
Deformed Wing Virus, types A & B
Scientific Name
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Varroa related Virus
Maine Notes
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Resource Links
Skunks
Scientific Name
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Pest
Maine Notes
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Resource Links
Deformed Wing Virus, types A & B
Scientific Name
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Varroa related Virus
Maine Notes
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Resource Links
Mice
Scientific Name
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Pest
Maine Notes
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Resource Links
Wasp - Asian Hornet a/k/a Yellow Leged Hornet
Vespa velutina
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Pest
Not in Maine
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Resource Links
Wasp - Common “Yellow Jacket”
Vespa mandarinia
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Pest
Not in Maine
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Resource Links
Wasp - Northen Giant Hornet
Vespa mandarinia
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Pest
Not in Maine
Wikipedia
Photo Credit
PDF of Paper - Taylor, B.A., Tembrock, L.R., Sankovitz, M. et al. Population genomics of the invasive Northern Giant Hornet Vespa mandarinia in North America and across its native range; Scientific Reports; 2024.
Press Release - USDA APHIS (Animal and Plant Health Inspection Service) - Victory Over the World’s Largest Hornet Species, 2024
iNaturalist Species web page for Vespa mandarinia
Mite - Tracheal
Acarapis woodi
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Pest
Maine Notes
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iNaturalist taxa page for Acarapis woodi
Mite - Varroa destructor
Varroa destructor
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Pest
Common in Maine.
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web pages - iNaturalist taxa guide for Varroa destructor
Mite - Tropilaelaps a/k/a Tropi
Scientific Name
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Pest
Not known to be in Maine. A regulated pest that must be reported.
Bee Aware
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Small Hive Beetle
Aethina tumida
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Pest
Maine Notes
AHPA (American Honey Producers)
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web pages - iNaturalist taxa information on Aethina tumida
Wax Moth
Scientific Name
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Pest
Maine Notes
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Resource Links
Mite - Varroa jacobsoni
Scientific Name
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Pest
Not found in Maine. Must report to State Apairy Department if found - a pest identified in legislation. Initially, Varroa destructor was misidentified as Varrroa jacobsoni.
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web pages - iNaturalist species pages on Varroa jacobsoni
Colony Collape Disorder
Scientific Name
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Syndrome
Maine Notes
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Resource Links
”Africanized” honey bees
Apis meliffera scutellata
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Pest
Very occasionally unintentionally imported into Maine and not believed to survive Maine winters. A regulated “pest” that must be reported.
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Resource Links
Varoosis
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Syndrome
A colony displaying effects of Varroa Mite infestation
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Carl Hayden Bee Research Lab - Web Page on Varroosis.