Honey Bee Brood Diseases (ABEJAS Module 3.3)

Text Transcript with Description of Visuals

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Welcome to the third video in module three of ABEJAS.
ABEJAS Logo in front of honey bees crawling on hive frame containing brood

Title: Module 3.3 Honey Bee Brood Diseases
Honey bees get sick for several reasons. Viruses, bacteria, parasites, poor nutrition, environmental stress, and poor hive management.Beekeeper in an apiary talking to camera
These factors weaken their immune systems, making them more susceptible to diseases.Bee climbing on purple flower
This video will introduce you to honey bee brood diseases and the signs you may see.Beekeeper inspecting both sides of hive frame
Typically, brood diseases involve bacterial or fungal pathogens that directly affect larval and pupal development, leading to visible signs of diseases in the brood.Closeup view of hive frame dead pupae uncapped and normal capped brood. The comb has an uneven jagged pattern indicating wax coverings were chewed

Bees flying into hive entrance with someone approaching hive in the background
[Music]ABEJAS Logo in front of red background. Text on screen: Healthy brood and sick brood
Before looking for sick brood, it is important to first learn what healthy brood looks like. Healthy larvae are pearly white, C-shaped and lay flat on the bottom of their cells.Hive frame containing cells with various stages of bees including young larva, older larvae, and capped brood. Text on screen: Healthy brood
Healthy pupae are fully covered by a wax capping that is slightly domed and dry.Hive frame containing cells with various stages of bees including young and older larvae in large puddles of liquid. Text on screen: Healthy larvae
Ages of brood are typically grouped together.Hive frame containing cells with various stages of bees including adults, young larva, older larvae, and capped brood. Capped brood is clustered into groups. Text on screen: Healthy pupae and larvae
You should see mostly solid patches of capped brood with few empty spaces.Hive frame containing a large collective pattern of capped brood cells and adults crawling on frame. Text on screen: A good brood pattern
To identify sick brood, look for the absence of healthy brood. Then look closer to see if you can determine the cause of the issue. A poor brood pattern where there are lots of empty spaces may indicate a brood disease.Beekeeper inspecting hive frame, close up view of frame with sporadic capped cells and shriveled larvae in cells. Text on screen: A poor brood pattern with signs of mites and disease
[Music]ABEJAS Logo in front of red background. Text on screen: Chalkbrood
Chalkbrood is a fungal pathogen that causes bees to turn into chalky looking mummies.Beekeeper in an apiary talking to camera
You may find these mummies on the bottom board, the front entrance of the hives, or even on the ground in front of the colony. Bees infected with this pathogen are inundated with the hyphae of the fungus.Blue forceps picking up grey and white pellets sitting at hive entrance. Text on screen: Chalkbrood at the front entrance of a hive
When the fungus is still growing, the pupae look like a white pellet.White pellet sitting on hive frame cells, red circle around pellet appears. Text on screen: In this example, the chalkbrood fungus is still growing
When the fungus sporulates, the mummy is mostly black.Dark grey pellet sitting on hive frame cells, red circle around pellet appears. Text on screen: Here, the fungus has sporulated
This pathogen is more likely to occur in damp areas. Though primarily a brood disease, the colony can be weakened, shows signs of poor hygiene, or have reduced foraging efficiency.Hive frame with capped brood, some cappings are peeled away and white underneath. Text on screen: Signs of chalkbrood under capped brood cells
There are no chemical treatments for chalk brood.Hive frame with bulbous capped brood, blue forceps hold a grey pellet. Text on screen: Chalkbrood in a colony with a drone-laying queen
General recommendations are to keep colonies in locations with good water drainage and or increase hive ventilation. This pathogen is easily distinguished from the viral and bacterial pathogens that infect the brood that we will be discussing next.Close up of hexagonal cells containing larvae infected with chalkbrood. Text on screen: Keep colonies in locations with good water drainage and/or increase hive ventilation. Text on screen: Chalkbrood in uncapped cells
[Music]ABEJAS Logo in front of red background. Text on screen: Sacbrood
Sacbrood virus causes disease in developing brood. It spreads when adult bees ingest contaminated food or remove infected larvae from the hive.Beekeeper in an apiary talking to camera. Image of larva held by forceps appears. [Credited image: Rob Snyder, BIP] Text on screen: Sacbrood virus
Infected adult bees do not show any obvious signs, but the food producing hypopharyngeal glands of young bees can become infected, and they can pass along the virus to the brood they feed.Honey bees crawling on hive frame
This virus causes colonies to be weakened or can lead to colony death if the infection is severe.Pointy white larvae sitting in hexagonal hive cell, red circle appears around larva. Text on screen: Sacbrood
Signs of sacbrood virus include dead late stage larvae after the cell has been capped. An infected larva dies with its pointy head sticking up. If you pull out the dead larva with forceps, it is a droopy sack.Bee inspecting pointy white larvae sitting in hexagonal hive cell. Text on screen: Signs of sacbrood virus. Also observe a poor brood pattern
Signs are most apparent in recently capped brood cells after the larva stretches out on its back. Recently dead larvae are off white or yellow and will darken to a black color over time. Larvae that have been dead for a while will dry out and adhere loosely to the cell, creating a scale that can be easily removed.Pointy white larvae sitting in hexagonal hive cell surrounded by capped brood cells and adult bees, red circle appears around larva [Image credited: Montana State University, Flenniken Lab] Text on screen: Sacbrood
There are no chemical treatments for colonies with sac brood. General recommendations are to requeen and or remove infected brood comb to reduce viral levels in the colony.Beekeeper lifting lid of cardboard box labeled “Live queen bees”, beekeeper placing a caged queen in between two hive frames. Text on screen: Requeen and/or remove infected brood comb to reduce viral levels
[Music]ABEJAS Logo in front of red background. Text on screen: Foulbrood
Foulbrood is a bacterial disease caused by two different species of bacteria. American foul brood, AFB, and European fellow brood, EFB. There are a couple of ways to distinguish between the two forms of the disease. EFB infected larvae normally die before the bees cap the cell, and AFB infected brood die after capping.Beekeeper in an apiary talking to camera

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Images of hive frames containing brood appear [Images credited: Rob Snyder, BIP] Text on screen: American foulbrood (AFB), European foulbrood (EFB)
The ropiness test is the classic field test for determining whether the disease is AFB or EFB. Just poke a toothpick into the cell with the dead larva or pupa, stir, and pull it out of the cell. If it forms a stringy, ropey, or snotty connection between the comb and the tip of your toothpick, then it is almost certainly AFB. However, when a secondary bacterium commonly associated with EFB is present, it may cause some extra ropiness, so this test can sometimes be unreliable to clearly diagnose between AFB and EFB.Beekeeper poking thin stick into a hexagonal cell, yellow stringy material attaches to the stick as the beekeeper pulls out. Text on screen: The “ropiness test”

Text on screen appears: Notice the holes in some of the capped brood cells

Text on screen appears: The test in this example indicates a positive likelihood of American foulbrood (AFB)
Foulbrood can be transmitted with a hive tool, so be mindful of ways to avoid spreading AFB among colonies. Sterilize your hive tool using fire and work sick colonies last. Beekeeper using one hive tool to scrape debris off another hive tool, then fire is used to sterile tool. Text on screen: Sterilize your hive tool and work sick colonies last
Text on screen appears: Be mindful that cleaning your hive tool and using fire my not kill all of the AFB spores
In AFB infested hives, you may see cells with holes in their wax cap. A pupa dies after capping. Worker bees can sometimes detect that something is wrong and then chew open the wax capping to investigate.Beekeeper in an apiary talking to camera

Image of capped brood with perforations in the wax cappings appears [Image credited: Stephen K. Repasky] Text on screen: AFB, Cells with holes in their wax caps

Image of capped brood with sunken concave appearance [Image credited: Stephen K. Repasky] Text on screen: AFB, Sunken brood cells

Image of capped brood with perforations in the wax cappings and sunken cappings appears [Image credited: Maryann Frazier] Text on screen: AFB, Advanced AFB
European foulbrood is caused by a bacteria called Melissococcus plutonius, but six or more bacterial species commonly present as secondary invaders. Larvae tend to become infected younger than those infected with AFB. EFB is transmitted from nurse bees to young larvae during feeding. Hive frame with bees, capped brood, and larva. Some larva are malformed, red circles appear around malformed larvae.
Close up of two malformed larvae in adjacent cells. Text on screen: European foulbrood (EFB)
The classic signs are twisted or melted, looking yellow to brown larvae. Secondary bacterial infections can create a foul smell. Beekeeper talking to camera

Image of brown larvae [Image credited: Georgia Department of Agriculture] Text on screen: European foulbrood (EFB)
Often it requires a high level of infection for frames to have a noticeable smell.Beekeeper inspecting frame and lifting it to his face to smell
Once found, manage a colony with American foulbrood immediately. American foulbrood is a spore forming bacteria and is highly contagious. An extreme and best way to deal with American foulbrood is to burn the equipment.Beekeeper carrying hive box and placing in a metal barrel. Adjacent metal barrel has a hive box that is on fire. Text on screen: Manage a colony with AFB immediately

Closer view of hive on fire in metal barrel. Text on screen: burn infected equipment
If you can’t burn the infected equipment, use thick trash bags. Double bag the infected comb, then throw it away.Person moving two hive frames into black trash bag then typing bag. Text on screen: Manage a colony with AFB immediately. Double bag and discard infected comb
Scorch any woodware, lids, the box itself, etc. with a weed burner or propane torch.Person using a blow torch to sterilize hive box. Text on screen: Manage a colony with AFB immediately
If it is early enough in the spring or summer, you can save the bees by shaking them onto new foundation and feeding medicated sugar syrup. Also, treat the rest of the colonies in the apiary with antibiotics. Do not just administer antibiotics to the colony infected with American foulbrood without getting rid of the equipment.Tylan and powdered sugar. Text on screen: Manage a colony with AFB immediately. Treat all of the colonies in the apiary with antibiotics. Antibiotics require a prescription from a licensed veterinarian
The American foulbrood spores stay viable in comb for decades and will be a reoccurring problem.Beekeepers putting hive boxes in metal barrels
Although European foulbrood is not spore forming, the bacteria can stay in the equipment. One challenge of European foulbrood is that the other colonies in the location can carry the disease without signs, so cleaning up one colony and its hive equipment does not mean that the disease won’t pop back up. Six pallets of colonies in a circle formation, beekeepers working in colonies. Text on screen: Control EFB on an apiary level
Manage European foulbrood at an apiary level. Antibiotics are effective and can treat colonies with the disease.Person sprinkling white powder on top of hive frames using a measuring scoop. Text on screen: Control EFB on an apiary level, Antibiotics are effective
[Music]Hive frame containing cells with pollen and various stages of bees including young larva, older larvae, capped brood, and adults.
Managing all these diseases requires understanding their specific signs, lifecycles and how to apply targeted treatments or interventions to maintain colony health. Now that we’ve covered brood diseases, we will conclude this module with adult diseases in the next video.Beekeeper in an apiary talking to camera

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[Music]Close up view of larvae inside hexagonal cells

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