About Rob Snyder

I currently work out of the Butte County Cooperative Extension in Oroville, CA as a Crop Protection Agent. I received my B.S. in biology from Delaware Valley College, PA. There I attained a majority of my entomological knowledge from Dr. Chris Tipping and Dr. Robert Berthold. After graduation, I was an apiary inspector for 2 years at the Department of Agriculture in Pennsylvania. In my third year there, I still inspected some colonies but I mainly focused on The Pennsylvania Native Bee Survey (PANBS) where I pinned, labeled, entered data and identified native bees to genus species. Leo Donavall assisted me in learning the basics on positive Identifications of the native bees. Around the same time I began working on coordinating kit construction and distribution for the APHIS National Honey Bee Survey. I was also fortunate to conduct many of these surveys with fellow co-worker Mike Andree and Nathan Rice of USDA/ARS throughout California. All of these experiences have led me to where I am today, working to assist beekeepers in maintaining genetic diverse colonies resistant to parasites while reducing the use of chemical treatments in colonies. The BIP Diagnostic Lab at the University of MD is in an integral part of this process by generating reports in which we can track change and report to beekeepers vital information in a timely manner which may influence their treatment decisions.

European Foulbrood (EFB)

Worker cleaning her proboscis.

Worker cleaning her proboscis.


EFB is often found when nectar flows are sporadic or there is an insufficient number of nurse bees to attend brood. How does EFB spread? European Foulbrood (Melissococcus plutonius) is transmitted when the bacteria become mixed with the bee bread, nectar or diluted honey, and then fed to young larvae. The bacteria then replicate in the larvae mid-gut, killing the larvae within 4-5 days. This causes the larvae to die before sealed in most cases. When the larvae dies it is left in a “stomach-ache” position making it look contorted or twisted in the cell. If the larvae are fed a small amount of the bacteria it may die while sealed or have a decreased lifespan. At this point, EFB looks similar to AFB with scattered sunken cells with perforations. You may also see this if the larvae are fed copious amounts of food to prevent starvation. There are several secondary bacteria associated with EFB. This is often why the disease looks different in many cases depending on how severe the infection is. In hygienic colonies an EFB infection can be mistaken for a failing queen or spotty brood pattern because the bees are removing infected larvae and pupa at a fast rate. This bacterium, like AFB, is very contagious and all equipment should be cleaned once an infection has been found. This bacterium can stay contagious for years but does not produce spores like AFB.
Samples can be taken and sent to the USDA Honey Bee Lab for confirmation of this disease.
Symptoms:

Brood frame A with Eurpoean foulbrood disease.

Brood frame A with Eurpoean foulbrood disease.

Various stages of EFB.

Brood frame B with Eurpoean foulbrood disease.

Brood frame B with Eurpoean foulbrood disease.

• Spotty brood pattern, whitish-yellow to brown larvae, curled upward or twisted.
• Deflated larvae in the bottom of the cell with a defined tracheal system (usually greyish to brown in color with white trachea.)
• Sometimes ropes stretching up to 1.5 cm.
• Odors produced can be sour or fish-like, or no odor at all (different odors can come from secondary bacteria.) Scale is usually from brown to black sunken to the bottom of the cell.
• Outside frames of the brood nest are usually infected first.

Early stages of EFB.

Early stages of EFB.

EFB after sevaral weeks in the hive.

EFB after sevaral weeks in the hive.

Treatments:
The only product labeled for control of EFB is Terramycin (Oxytetracycline hydrochloride). If the colony is infected it is important to treat 3 times with Terramycin 5 to 7 days apart. Re-queening may help by breaking the brood cycle. The shook swarm method and a good nectar flow will also clear up EFB.

For more information and images please visit my older posts HERE.

BQCV (Black Queen Cell Virus)

Healthy Queen with cell pulled opened up for the photograph.

Healthy Queen with cell pulled opened up for the photograph.

So what is a virus? A virus is an infectious agent that parasitizes a host cell to replicate. Viruses can cause clinical symptoms, larvae death, or no symptoms at all. BQCV is caused by a virus in the family Dicistroviridae. BQCV is in the genus Cripavirus, which is different from other viruses like Acute Bee Paralysis Virus (ABPV), Israeli Acute Bee Paralysis (IAPV) and Kashmir Bee Virus (KBV) in the genus Aparavirus. Dicistroviruses infect many common insects like ants, bees, flies, leafhoppers, and aphids. The queen production industry is more likely to see this virus (hence its name) but it is still found in smaller operations. Indeed, in most surveys (including the BIP), BQCV is second only to Deformed Wing Virus (DWV), the well-know calling card of varroa. As its name indicates, the BQCV virus primarily attacks developing queens. The virus can still be found in workers and drones, but they do not appear to have any symptoms. This virus is typically detected by PCR, or polymerase chain reaction, a common molecular technique that amplifies the unique genetic signature of the virus.

BQCV larvae in a queen cell.

BQCV larvae in a queen cell.

Queen larvae, when infected, will die and turn a pale yellow color. The larvae will then darken, turning from brown to black. Interestingly, because it is unusual for most pathogens, BQCV kills its host larva at different stages of development, so the remains can be seen at any point after cell capping. Once the larvae are black, you may notice that the outside of the wax queen cells will have a black “oily” spot on them, indicating a dead larva inside. BQCV has been associated with nosema and other viruses, but it is unclear if nosema actually vectors (directly transmits) the virus or if the gut parasite merely takes advantage of an already sickened larva. Varroa infestations have also been linked to BQCV in the workers.

A closer view of a queen with BQCV.

A closer view of a queen with BQCV.

Symptoms:

• Larvae/Pupae turn pale yellow with tough skin at first, similar to Sacbrood Virus, but in queen larvae only.
• Larvae/Pupae then darken from brown to black. At this stage the exterior of the cell wall will appear to be dark.
• If one queen cell appears symptomatic, ‘candle’ the remaining cells in the same graft to inspect them for proper development

Queen cells ready to be placed into nucleus colonies for mating.

Queen cells ready to be placed into nucleus colonies for mating.

Remedies:

Unfortunately, as for almost all viruses, there is currently no vaccine or medication for BQCV. The following practices may help hinder the spread of the virus: Sanitation of grafting tools (in ethanol or by flame), control of varroa and nosema, and well-fed Breeder, Starters, Cell builders, and Mother colonies. I have also heard from beekeepers that antibiotics like fumagillin or even Terramycin (oxytetracycline hydrochloride) can clear up BQCV symptoms, possibly because it disrupts the potential interaction with nosema disease.

Ventral side of a varroa mite.

Ventral side of a varroa mite.

Chalkbrood

Drone brood with Chalkbrood.

Drone brood with Chalkbrood.

Chalkbrood (Ascosphaera apis) is typically observed during the spring but symptoms can be seen throughout the year. Chalkbrood contaminates larvae when the spores are mixed with brood food. The fungus will outcompete larvae for food and eventually turn the larvae into a “chalk-like” mummy. The color of chalkbrood ranges from white to grey then starts to turn black-this is when the fungus is producing fruiting bodies. This is the most infectious stage of chalkbrood. The black looking mummies are often what you see outside on the entrance board or in front of the hive. At this point these mummies can spread spores to other colonies in the area. Lack of population may be a contributing factor in the colonies ability to ventilate properly. Proper hive ventilation should prevent chalkbrood.

Chalkbrood taking over a drone larvae.

Chalkbrood taking over a drone larvae.

Symptoms:
• Spotty brood pattern.
• Chalk-like mummies at the colony entrance, chalk-like mummies in open brood.
• Early stages of chalkbrood look very similar to SBV but the head is less defined and more round with a sunken appearance.

Brood frame riddled with chalkbrood mummies.

Brood frame riddled with chalkbrood mummies.

Different ages of Chalkbrood.

Different ages of Chalkbrood.

Larvae being replaced by fungal mycelium.

Larvae being replaced by fungal mycelium.

Treatment:
Apiguard or a thymol based treatment is active against chalkbrood. Vitafeed Green contains thymol and also works against chalkbrood. Beevital Chalkbrood is another product available for treating chalkbrood. Increased ventilation in the hive will help prevent chalkbrood.

Sacbrood Virus (SBV)

Sacrbood Virus (SBV)

Sacrbood Virus (SBV)

SBV or Sacbrood Virus (Morator aetatulas) often appears during spring or colony buildup and causes larval death. The pupa fails to pupate and has a “shrunken head” appearance. When you see perforations in the sealed brood with the infected larvae inside, the perforation is usually choppy or jagged indicating a problem. If the SBV pupa is totally open, the capping has been completely removed by bees and the pupa is most likely greyish-yellow to brown and starting to dry out. When removed the pupa looks similar to a slipper or canoe. Infected adult bees will have decreased life spans.
Symptoms:
• Perforated sealed brood, pupa present with undeveloped head.
• Color ranges from pearly white to pale yellow to brown and eventually to black, when it is in scale form it is brittle and easily removed.
Treatments:
The only known treatment is to re-queen.

Sacbrood Virus

Sacbrood Virus (SBV)

Sacbrood Virus (SBV)

SBV (Sacbrood Virus)

SBV under a perforated cap.

SBV Black "Chinese Slipper"

American Foulbrood (AFB)

In a colony heavily infested with AFB you will see moisture on the sealed brood.  You will also see brood oozing from perforated cells at this stage.

In a colony heavily infested with AFB you will see moisture on the sealed brood. You will also see brood oozing from perforated cells at this stage.

How does AFB spread? American Foulbrood (Paenibacillus larvae) is introduced to the hive by drifting bees from nearby colonies, infected equipment/tools, beekeepers and robbing. The infection begins when spores enter the hive, and then food contaminated by spores is fed to the larvae by nurse bees. Once spores are in the midgut the bacteria take over using the larvae as a source of nourishment. After the cells are sealed, death occurs. If death occurs while in the pupal stage, there may be a protruding tongue present. When there is a serious infection you can notice moisture on sealed brood as they start to sink. Sunken sealed cells are a result of decomposing larvae. AFB is very contagious and all equipment must be cleaned before using it in healthy hives.

The AFB scale is very hard for the bees to remove and can infect colonies for years to come. This is why some states have a “burn only” policy, but others allow the use of antibiotics to control the disease. It is important to have the AFB tested by a lab (USDA Honey Bee Lab) to identify if the AFB strain is resistant to Terramycin (oxytetracycline hydrochloride).

American Foulbrood (AFB)

American Foulbrood (AFB)

Symptoms:
• Spotty brood pattern, perforated sealed brood with coffee brown larvae inside, sunken sealed brood, coffee brown larvae sunken to the bottom of the cell.
• Moisture on sunken sealed brood, protruding pupal tongue (rare), and rotting smell (compared to rotting meat or sulfurous chicken house).
• Light to dark brown to black scale that is hard to remove.
• Often colonies next to infected colonies will show symptoms of the disease.
• Larvae rope at least 2 cm.

AFB: Symptoms in open brood.

AFB: Symptoms in open brood.

Treatment:
It is best to burn all colonies infected with AFB but you can treat infected colonies with antibiotics. There are two antibiotic treatments for AFB: Terramycin and Tylan. If AFB is not resistant to Terramycin (oxytetracycline hydrochloride) then this antibiotic is used. If the strain of AFB is resistant to Terramycin, than Tylosine is the antibiotic used to treat the colony. Treating colonies 8 weeks prior to the nectar flow is recommended to prevent honey from being contaminated.
Note: Tylan is supposed to be used once symptoms occur in the hive because it leaves behind residuals for far longer than Terramycin. Terramycin is the only antibiotic that can be legally used prophylactically.

This is often how I will see AFB in a colony.  Most of the open brood has been removed by the bees.  But you will still find ropy larvae/pupa under perforated seaed brood.

This is often how I will see AFB in a colony. Most of the open brood has been removed by the bees. But you will still find ropy larvae/pupa under perforated seaed brood.

AFB: Scale forming in cells

AFB: Scale forming in cells

American Foulbrood (AFB) Deadout.

American Foulbrood (AFB) Deadout.

Parasitic Mite Syndrome (PMS)

Varroa mites feeding on unsealed brood.

Varroa mites feeding on unsealed brood.

PMS or Parasitic Mite Syndrome is a condition that causes a honey bee colony to deteriorate and eventually dwindle away and die. There has not yet been a pathogen detected which causes the brood symptoms that appear with this syndrome. However there are always varroa mites present with this syndrome. The brood symptoms look similar to other diseases but the larvae don’t rope. Colonies with PMS will show symptoms of white larvae that are chewed or pecked down by workers. Larvae may appear sunken to the side of the cell and may show symptoms of white with some debris at the posterior end. Pupa will be chewed down/removed or the pupa face chewed part of the way down as seen in the photo. Most of the symptoms shown are from hygienic bees trying to remove varroa mite infested cells and or larvae/pupa from cells. There is sometimes color to the larvae and this is attributed to age, decomposition or secondary bacteria.

When you start to see pupa with their face chewed down(multipule cells), this is a sign that your mite levels are starting to climb.

When you start to see pupa with their face chewed down(multipule cells), this is a sign that your mite levels are starting to climb.

Symptoms:
• Spotty brood pattern, varroa mites present on adult bees.
• Mites can often be seen crawling across sealed brood.
• Mites can also be found in open brood cells (usually chewed down larvae, refer to images)
• Lack of adult population (time-dependent).
• Large colonies are aggravated by high varroa mite levels and often show increased aggressiveness, lack of eggs and developing larvae (due to unfit conditions for raising brood), supercedure cells are often present, crawling bees near hive entrance or bees with DWV (Deformed wing virus).
• No odor present until the chewed down larvae start to change color and decay.

Note the spotty brood pattern.  The mite infestation is so bad that the bees start to chew down pupa/larvae and stop brood production.  You may also notice supercedure cells.

Note the spotty brood pattern. The mite infestation is so bad that the bees start to chew down pupa/larvae and stop brood production. You may also notice supercedure cells.

Here is an image of PMS.

Here is an image of PMS.

Chewed down pupa, larvae and a varroa mite hiding in the bottom of a cell.

Chewed down pupa, larvae and a varroa mite hiding in the bottom of a cell.

PMS symptoms.

PMS and  Deformed Wing Virus(DWV).

PMS and Deformed Wing Virus(DWV).

This is what PMS looks like once the population of the colony has dwindled.  You will not see many mites present at this stage of PMS; there will also be very little open brood present in the colony.  The population will be small and you may see multiple supercedure cells. At this stage PMS looks very similar to European Foulbrood except the larvae are different ages and there is no uniformity when it comes to open brood symptoms.

This is what PMS looks like once the population of the colony has dwindled. You will not see many mites present at this stage of PMS; there will also be very little open brood present in the colony. The population will be small and you may see multiple supercedure cells.
At this stage PMS looks very similar to European Foulbrood except the larvae are different ages and there is no uniformity when it comes to open brood symptoms.


Click here EFB Blog to see images of EFB.

You will often find Supercedure cells in colonies with high mite infestations.  You will also see supercedure cells with other disease like EFB.

You will often find Supercedure cells in colonies with high mite infestations. You will also see supercedure cells with other disease like EFB.

High mite infestation in brood.

High mite infestation in brood.

Treatments:
Keep varroa mite levels low. Monitor varroa mite levels or treat at least twice a year for varroa mites.

Bald Brood video

In April 2013 I wrote a blog about Bald Brood. Since then I have captured a video of myself digging out the wax moth larvae from the sealed brood. Whenever I see these symptoms I always try to remove the wax moth. For more information on bald brood please see my previous blog HERE.

Neglected Drone Brood

Drone bee next to a queen.

Drone bee next to a queen.

Throughout the year several honey bee diseases can be noted in stressed or sick colonies. There are also other stress factors that cause colony conditions to deteriorate and look very similar to sick or diseased colonies. One condition is neglected drone brood. It is caused by either a drone laying queen, laying workers, poorly mated queens, or failing queens. The size of the colony will determine how long it takes to dwindle down and show signs of neglected drone brood. Most of the photos are from a colony that had a poorly mated queen. The symptoms appeared 10 days after she started to lay. In a normal sized colony it would take some time for the colony to dwindle down to where the nurse bee cannot sufficiently feed larvae or maintain larvae due to lack of foragers bringing in food. This also disrupts the ventilation in the hive and you can start to see things like chalk brood show up in some cases. You may also note that there are malformed drones in large numbers depending on colony size. Supercedure cells or replacement cells may be present. These cells should be nicked out because they are probably drone.

Drone Laying Queen.

Drone Laying Queen.

So what does the brood look like? The sealed drone brood looks like a normal drone layer, but the open brood looks similar to EFB and the scale stage looks like AFB. This is due to brood starving then decomposing. The color goes from white to yellow to a brownish-black color. Sometimes it may appear to be a greyish color. The larvae can also die from the lack of ventilation from either overheating or chilling.

Honey bee frame with neglected drone brood.

Honey bee frame with neglected drone brood.

Recommended treatment for neglected drone brood depends on how bad the condition is. In many cases most of the equipment should be destroyed since a large percentage of worker cells have been transformed to drone cells. You can however scrape all remaining drone brood and place the frame into a strong colony and it may be fine.

Here are some images below to show you different colonies with neglected drone brood.

Here are neglected drone cells that have been chewed down by the remaining workers in attempts to remove them from the cells.

Here are neglected drone cells that have been chewed down by the remaining workers in attempts to remove them from the cells.

Neglected drone brood.

Neglected drone brood.

Start of scale from neglected drone brood.

The start of scale from neglected drone brood.

Here is an image of the scale of neglected drone brood.

Here is an image of the scale of neglected drone brood.

Bald Brood

Greater wax moth adult.

Greater wax moth adult.

This image shows a section of a frame with a wax moth tunneling below sealed brood.  This symptom is called Bald Brood.

This image shows a section of a frame with a wax moth tunneling below sealed brood. This symptom is called Bald Brood.

An interesting brood symptom you may come across in a weak hive in the spring is Bald Brood. Bald brood is caused by the Lesser wax moth (Achroia gresella) or the Greater wax moth (Galleria mellonella.) You can see in the image below the linear pattern of uncapping that occurs due to the wax moths tunneling behavior. These symptoms can sometimes be confused as hygienic behavior; I have included an image showing some hygienic behavior of uncapping. One visible difference between hygienic behavior vs. bald brood is that there is no linear pattern of uncapping sealed brood with hygienic behavior. Colonies with bald brood often have raised sidewalls that are slightly above the other sealed brood, this symptom is not usually present when bees are uncapping larva/pupa associated with varroa, a lethal gene or another brood disease. I have seen these symptoms a handful of times over the past several years but in most cases the colonies were weak ranging from 3-6 Frames of bees. The best defense against wax moth is a strong colony. If you investigate cells near the ends of the linear pattern you can probably find the wax moth larva, look for perforations in the sealed cells. For more information on wax moth please see my previous wax moth blog here “Wax Mothor “Jennie’s blog on Wax moth damage”.

This image is cropped from the image above to give you a close up of what bald brood looks like.  You can see the raised cell walls around the uncapped pupa.  Also, note the darker brown convex sealed cells in between the open cells (convex but not normal looking.)  This was the path of the wax moth larva.  There is a perforation in the cell to the right of the last uncapped cell.  I found the wax moth in that perforated cell.  There is a photo of the wax moth larva below.

This image is cropped from the image above to give you a close up of what bald brood looks like. You can see the raised cell walls around the uncapped pupa. Also, note the darker brown convex sealed cells in between the open cells (convex but not normal looking.) This was the path of the wax moth larva. There is a perforation in the cell to the right of the last uncapped cell. I found the wax moth in that perforated cell. There is a photo of the wax moth larva below.

Wax moth larva that was removed from the perforated cell pictured above.

Wax moth larva that was removed from the perforated cell pictured above.

Bald brood is caused by the wax moth tunneling below the sealed brood.  Bees can detect something is wrong when the wax moth is tunneling below and start to uncap cells.

Bald brood is caused by the wax moth tunneling below the sealed brood. Bees can detect something is wrong when the wax moth is tunneling below and start to uncap cells.

This image shows the results of a hygienic test.  You can compare the edges of the open cells to the open cells in the bald brood image.  This image also shows how the hygienic bees will start to chew down and remove pupae and larvae.

This image shows the results of a hygienic test. You can compare the edges of the open cells to the open cells in the bald brood image. This image also shows how the hygienic bees will start to chew down and remove pupae and larvae.

This is an image of hygienic behavior.  The bees are uncapping and chewing down larvae because they detected varroa mite, a lethal gene or some other brood disease.  Note there is no real pattern to the uncapping.  Also note the pepperbox brood pattern.

This is an image of hygienic behavior. The bees are uncapping and chewing down larvae because they detected varroa mite, lethal gene or some other brood disease. Note there is no real pattern to the uncapping. Also note the pepperbox brood pattern.

One may confuse the linear uncapping for early stages of chalkbrood so I have included this image to compare to bald brood.

One may confuse the linear uncapping for early stages of chalkbrood so I have included this image to compare to bald brood.

In this image you can see hygienic behavior displayed in circled uncapped brood.  I also circled some other problems related to varroa mite.  You will see a few bees circled with Deformed Wing Virus (DWV.)

In this image you can see hygienic behavior displayed in circled uncapped brood. I also circled some other problems related to varroa mite. You will see a few bees circled with Deformed Wing Virus (DWV.)