Diseases, Pests, Parasites and Predators of Honey Bees

Below you will find lists of the diseases, pests, parasites and predators of honeybees (in North America), how to recognize their presence in the hive and the current recommended treatment/prevention.

Diseases of the Honeybee

• American Foulbrood (Bacillus larvae) Abbreviated as AFB
  • How to recognize AFB: Brood that are infected by AFB quickly die in the cells. The cell cap will be sunken rather than rounded and will typically be pierced or punctured. If you can see the larvae in the cell they will look melted and there will be a distinctive sour odor to the frame. Odor however, is not a positive identification of American Foulbrood. Another test is to take a small piece of wood (toothpick, twig, matchstick, etc) and insert into a suspect cell. Stir the remains and then slowly withdraw the stick; if you can pull the mass out (about an inch) and it adheres to the stick and the larval mass then it is highly likely that you have AFB.
  • How to treat for AFB: If you have AFB in your hive, there is no true treatment to eliminate it from the colony. The only effective method is to burn the hive to ash. However, it is possible to soak the frames in lye water for 24 hours and this may kill the spores; you then scorch the interior of the hive to kill the spores. If you suspect that a hive of yours has AFB, contact your local bee inspector or department of agriculture for the recommended treatment. You can also contact your local beekeeping association for assistance.
  • How to prevent AFB: AFB can be prevented by maintaining strong colonies. Also a preventative treatment of oystercatcher (Terramycin) can be applied.
• European Foulbrood (Melissococus pluton) Abbreviated as EFB
  • How to recognize EFB: Unlike AFB, larvae infected with EFB typically die BEFORE being capped. They lie twisted at the bottom of the cell in a reverse corkscrew shape. They will be a tan to brown color and will appear melted. EFB killed larvae do not exhibit the same "ropy" results of a stick test like AFB. There may be a sour odor present but it will different than AFB.
  • How to treat for EFB: EFB can be effectively controlled with antibiotics (Terramycin). Also, requeening your hive will help as it breaks the brood cycle and the EFB reproduction cycle.
  • How to prevent EFB: Keep a young vigorous queen in the hive (requeen every couple of years) and help the hive stay healthy and strong. Preventative treatments with antibiotics will help.
• Chalkbrood (Ascophaera apis)
  • How to recognize Chalkbrood: Chalkbrood is a fungal disease that affects the brood once they are sealed in the cells. Once they are dead, the larvae are chalky white and resemble mummies (kind of) that are spotted on the underside where the fungus discolors the corpse. These dead larvae are then drug out of the hive and deposited in the area in front of the landing board. It is then that you will notice the disease. These corpses will be hard and chalky rather than soft and squishy.
  • How to treat for Chalkbrood: no treatment is recommended as colonies can recover on their own. However, you can requeen to help break the brood cycle. Also, chalkbrood will typically infect one frame at a time; remove this frame, freeze it and scrape it clean.
  • How to prevent Chalkbrood: Keep your hives healthy with good ventilation. Requeen every few years to keep a young vigorous queen laying good eggs in the hive.
• Sacbrood
  • How to recognize Sacbrood: Sacbroon is a viral disease that typically is not a great concern. Brood that are affected change from pearly white to yellow, brown and eventually black. The entire larvae can be easily removed and will be contained in a sac like membrane. Typically, the colony overcomes sacbrood on their own without the beekeeper ever being aware of a problem.
  • How to treat for Sacbrood: There is no medical treatment for sacbrood currently. If the colony has noticeably sacbrood, remove as much infected larvae as possible.
  • How to prevent Sacbrood: Keeping your hive healthy and strong as well as regular requeening will help reduce or eliminate the incidence of this disease.
• Chilled Brood
  • How to recognize Chilled brood: Chilled brood occurs when the brood chamber becomes too large for the bees and they cannot keep the developing young warm. Brood killed in this manner turn gray and may resemble sacbrood.
  • How to treat for Chilled brood: There is not real treatment for chilled brood; once the weather warms or the colony grows, they will be able to care for the brood more effectively.
  • How to prevent Chilled brood: Do not work your bees in cold weather, replace frames in the same order they were removed when performing cool weather inspections and do not leave frames of brood outside of the hive for any longer than absolutely necessary.
• Nosema (Nosema apis)
  • How to recognize Nosema: Nosema is caused by a protozoan and affects adult bees. The protozoan affects the digestive hind gut of the adults and can cause severe diarrhea which can be seen as fecal staining on the front of the hive. Another affect is that the sick bees cannot produce royal jelly or effectively feed brood resulting in brood reduction. This disease typically occurs in the spring.
  • How to treat for Nosema: an antibiotic such as Fumagillin can be used to treat the symptoms but it will not eliminate the spores produced.
  • How to prevent Nosema: Keep hives well stock with winter provisions of capped honey. Keeping the hive healthy and relatively free of other diseases, parasites and pests will also help. Good ventilation is a must.
• Dysentery
  • How to recognize Dysentery: Dysentery is not a true disease but a result of other diseases or conditions that prevent the bees from taking cleansing flights; it is also caused by food sources that are too water rich. Typically the bees defecate inside the hive and all over the hive entrance and landing board. These conditions can be caused by poor ventilation and food stores that did not ripen into true honey.
  • How to treat for Dysentery: A similar treatment to that of Nosema may help.
  • How to prevent Dysentery: Keep hives situated in such a manner as to prevent too much rain or snow accumulating on/in the hive. Ensure good ventilation and if a fall feeding is necessary, do so early enough to allow the bees to fully cure the food.
• Paralysis
  • How to recognize Paralysis: Bees that are seen to tremble uncontrollably and are unable to fly may be exhibiting signs of either Chronic Bee Paralysis Virus (CPV) or Acute Bee Paralysis (APV). They also loose their hair giving them a greasy look and they are submissive to attack (unlike robber bees who may have a similar appearance).
  • How to treat for Paralysis: There is no know treatment for these viruses. Some research indicates that susceptibility to these viruses may be genetically linked. Requeening or adding frames of sealed brood from a healthy hive may help.
  • How to prevent Paralysis: Maintain healthy colonies and requeen on a regular basis.

Pests of the Honeybee

• Bee Louse (Braula coeca)
  • How to recognize the Bee Louse: Bee Lice are small (about the size of a pin head) and reddish/brown in color and have a similar color/size to Varroa mites. However, bee lice move quickly over the body of bees where varroa is slower. Typically the lice will hide under the bee until it is hungry when it will scurry up to the mouth parts of the bee to sip nectar or honey.
  • How to eliminate Bee Lice: Bee Lice are susceptible to the same treatments as mites and are unlikely to be seen when proper mite prevention techniques are followed.
• Wax Moth (Galleria melonella)
  • How to recognize Wax moths: wax moth larvae can do considerable damage in a very short time. They tunnel through comb eating everything in their path. They leave silken threads wherever they go covering the entire frame in days. Once they pupate, their cocoons can easily be seen and they will tunnel into the wood slightly to build them. Typically, wax moths will attack empty supers that are unprotected or weak colonies.
  • How to eliminate wax moths: once a super/frame is covered in moth larvae you can try to scrape them back down to foundation. The only approved chemical treatment is paradichlorobenzene (PBD) crystals (urinal cakes). Place them only in empty supers and remove them to air out for several weeks before putting back on a hive. PBD crystals DO NOT kill the eggs to you will need to keep the treatment up for a couple weeks to eliminate them all. NEVER use mothballs - the chemical in moth balls remains in your wax and will transfer to your honey.
  • How to prevent wax moths: Keep empty supers in a dry cold location (winter) and when the temperatures are warm, keep empty supers/frames in a freezer. Another method is to lay supers with frames on their side and put a fan at one end to blow air through them constantly until temperature drop. For in colony, maintain a strong colony; combine weak colonies to prevent outbreaks. A strong colony will eliminate wax moths on their own; a weak hive is defenseless.
• Mice
  • Recognizing mice and their damage: Mice can damage stored comb and comb in the hive. They will typically move into both in the late fall as temperatures begin to drop. They seek an area in which to build winter nests and the bee's honey storage provides a nice food source as well. They chew up the comb (and foundation) and they also bring in nesting materials. Overall the effect is one of destruction (remember that mice urinate and defecate everywhere they go) and the bees will attempt to kill the invader. If they succeed, they have no method to remove the mouse, but instead coat it in propolis to prevent the spread of disease from the decomposing corpse.
  • How to eliminate mice: if found in supers (occupied or not) capture/kill them immediately. Clean the hive and replace any damaged frames.
  • How to prevent mice: raise your hives off of the ground. Place a mouse guard on the entrance of the colony to prevent them coming in; use at least an entrance reducer and watch for signs of chewing as mice will chew the wood to make the entrance large enough to get in.
• Ants
  • Recognizing ants and their damage: Ants do not typically cause damage, but instead raid the hive for the honey stores. However, some species will invade a hive to establish a colony; they will then destroy comb, brood, honey and pollen storage. This may cause the colony to abscond.
  • How to eliminate ants: First, eliminate the way the ants are getting in; raise the hive off of the ground and eliminate all brush around the hive. Keep the hive strong and they will keep the ants under control. Place a sticky barrier around the hive that ants cannot cross (oil, vaseline etc).
  • How to prevent ants: if ants appear to be going into the hive, try ground cinnamon. Sprinkle some around the hive and on the inner cover. Ants don't like cinnamon but the bees don't mind. You can also put the hive on a stand with legs that sit inside cans that have oil in them; the ants will crawl up, down and drown in the oil.
• Small Hive Beetle (Athina tumida) Abbreviated as SHB
  • How to recognize SHB: Small Hive Beetle larvae consume everything in the comb. They also defecate everywhere they go and this causes the stored honey to ferment and ooze out of the comb causing quite a mess. Eventually, the colony may abscond from the hive entirely.
  • How to eliminate SHB: Fortunately, SHB is currently restricted to the southeastern United States. However, it is probably just a matter of time until it finds its way across the country. The only chemical currently approved for the treatment of SHB is coumaphos (Checkmite+ strips). However, some beekeepers feel that treatments with mineral oil foggers and/or ascetic acid may also control this pest.
  • How to prevent SHB: The larvae of the SHB need to come outside of the hive and burrow into the ground to pupate. Keep your hive on top of a hard packed earth or possibly a concrete pad to prevent re-introduction into the hive. A strong colony will be able to keep the SHB under control; watch weak colonies. Kill any and all SHB that you encounter during routine inspections.

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Parasites of the Honeybees - below are the recognized parasites of honeybees that you need to know about.

• Varroa Mite (Varroa jacobsoni)
  • How to recognize Varroa mites: Varroa mites are small reddish/brown colored insects that feed off of the body fluids of adult bees as well as larvae. They are visible to the naked eye and are most easily seen on brood (especially drone brood). Another symptom of Varroa is the presence of "crawlers", bees whose wings are deformed and cannot fly (hence they crawl around). Varroa does not cause this disfigurement directly, instead they are a carrier for a virus that affects the bee while it is a larvae.
  • How to treat against Varroa: there are several methods to treat for varroa mites; a short list follows but you should research what other beekeepers are doing in your area to treat. You must learn to apply these correctly to prevent contamination of honey, and resistance develop by the mites.
    • Apistan Strips
    • Checkmite+ Strips
    • Sucrocide
    • Oxalic Acid
    • Formic Acid
    • Vaporized mineral oil
    • Ascetic Acid
    • Essential Oils
  • How to prevent Varroa: just as there are several ways to treat for mites, there are several ways to prevent them. In some cases, the treatment and prevention methods are the same.
    • Screened bottom boards
    • Powdered sugar treatments
    • Drone brood removal
    • Small cell foundation
    • Queen bees with genetic behaviors to reduce mite numbers
    • The same chemicals listed above for treatment can aid in prevention.

• Tracheal Mite (Acarapis woodi)
  • How to recognize Tracheal mites: tracheal mites live in the trachea (lungs) of the honey bee and are therefore impossible to see. However, the presence of bees that are incapable of flight, despite normal wings, may be an indication.
  • How to treat against tracheal mites: menthol crystals placed in hive can help significantly reduce the numbers of tracheal mites. Grease patties may also help lower the population.
  • How to prevent tracheal mites: the same methods for treatment can be used for prevention. Maintaining strong colonies will also help keep the effects of tracheal mites to a minimum.

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Predators of Honeybees

• Skunks
  • Signs of predation: skunks will scratch at the entrance of the hive to draw the bees out. They then consume the adult bees as the fly out of the hive. Typically this will happen at night and skunks can decimate a colony in no time at all. They also irritate the bees making them cranky and difficult to work. Look for signs of scratching on the hive and skunk feces with bee exoskeletons in it. There may also be mud and torn up vegetation in front of the hive.
  • Prevention: Raise your hive up off the ground; higher is better. Skunks must then stand on their hind legs to reach the entrance exposing their tender under belly to the stings of your colony. Another option is to take a piece of plywood and nail a lot of nails through it. Then place the wood, nails up, in front of the hive.
• Raccoons
  • Signs of predation: Raccoons are smart animals and can figure out how to take the cover off of your hive to get at the bees/brood/honey/pollen inside.
  • Prevention: place heavy rocks or bricks on top of the hive to prevent the racoon from lifting the cover off. Also try the plywood trick for skunks all around the hive.
• Bears
  • Signs of predation: while the presence of bears in Utah county is slim, you may take your bees into bear country someday. Bears will typically knock the entire hive over and scatter the frames and supers as it consumes everything in the hive. An apiary that has had a bear visitor is a sorry sight.
  • Prevention: an electric fence is the only truly effective method of keeping bears away from your hives. You could try a similar trick to that of skunk prevention an put larger nails through the boards - but you would need these to surround your entire apiary.
• Birds
  • Signs of predation: you may only notice birds eating your bees when they are in flight. The birds will swoop down near the hive and take the bees on the wing.
  • Prevention: almost impossible to prevent. However, the number of bees eaten by birds should be minimal (unless it is a whole flock).

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