Chalkbrood Disease and other Infections in Honey bees

Chalkbrood Disease and other Infections in Honey bees

There are different diseases that can affect a beehive, some more dangerous and deadly than the others but each requiring certain very specific measures to overcome the afflictions.

American Foulbrood

American Foulbrood

One of the most contagious and deadly of all the diseases affecting the bees is the American Foulbrood or AFB. Exposure to Paenibacillus larvae bacteria that survive through spore-forming tendencies causes AFB.

It is even more deadly as, even if you kill the bacteria, the spores remain. And spores by definition can live forever. These spores infect the honey along with the hive tools.

How do we identify infections by this bacterium? This particular disease affects the larvae of a bee colony. To identify American Foulbrood, a beekeeper is required to look for comb caps with the hole in them.

These caps are also a little sunken in the middle. This shows that the larva inside the comb cell is infected. Usually, a bee larva is thick and white, whereas, after infection by American Foulbrood, it becomes yellowish to brown in color and gives the appearance of being melted.

The dead larva is simply a brown stringy mass. If a beekeeper encounters any one of these signs it is a surety that the colony is infected by American Foulbrood.

What steps can a beekeeper take after diagnosing infection by American Foulbrood? First, there is a need to confirm the diagnosis as correct.

When you spot the symptoms contact a nearby apiary or bee organization to confirm your doubts about the infection. They would then direct you on how to go about safeguarding other beehives from further spread of infection.

The most that you can do is to burn the infected hives that you found so that you completely destroy all the spores and stop any reinfection. Also, essential is how you dispose of the hive tools and other beekeeping instruments that would have come into contact with the infected hives.

European Foulbrood

European Foulbrood
This is similar to the American Foulbrood except that this bacterium doesn’t form spores.

In this infection, the larva becomes yellow and dies even before the cell is capped. The larva becomes a rubbery mass in the open cells. It usually occurs when there is limited nectar availability or when there are fewer nurse bees available to take care of the hatched larvae.

Mostly a healthy colony can successfully survive European foulbrood attacks and overcome after some time, all on their own. Preventive measures include taking care that the colony is not stressed out, that their feed doesn’t pass out and general cleanliness is maintained.

Though this affects the larvae just as the AFB, it is vastly different in the fact that colonies fight off European foulbrood more easily due to the absence of spores.

Chalkbrood Disease

Chalkbrood Disease
This is a fungal infection. It again infects the bee larvae. This also spreads through spores but bees take diligent care in containing this infection and are fairly successful.

This infection causes the larvae and the affected brood to look like chalk. The larvae turn white and chalky. The nurse bees and the cleaner bees dispose of these dead chalky bodies of the infected larvae by carrying them out of the hive and dropping them far away from the hive structure.

The fungus grows alongside the larvae and eventually competes with and defeats the larvae in a race for food. After the larva dies, the fungus moves to eat the larva too, leaving behind a white chalky carcass.

This fungal infection is most common in wetter conditions. The fungus thrives in excess moisture, which can be highly dangerous for bees. Bees are known to recover on their own from this infection as the conditions improve and drier weather returns.

Sacbrood Virus

Sacbrood Virus
Though there are a few different varieties of viral diseases that affect bees, such as acute bee paralysis virus (ABPV), the black queen cell virus (BQCV), Sacbrood virus (SBV) and deformed wing virus (DW V), two are more commonly known and studied as these show definite symptoms whereas the others do not. These two are the Sacbrood and the deformed wing virus.

The Sacbrood virus infects the larvae and forms a kind of sac under the skin of the larvae. Such infected larvae foil to develop into the next stage of the pupa formation.

As the larva dies it forms a yellowish scale over the dead larva, and this gives a distinct symptom to identify the brood with. For preventive measures, cleanliness and tidiness around the hive and with the hive equipment and tools are necessary.

Deformed Wing Virus

deformed wing virus
This virus affects the adult bees. This results in the bees having deformed or withered wings that are more or less useless. The bee thus infected cannot overcome the infection and is bound to die within the first forty-eight hours after infection manifests. Their abdomens may also appear discolored, and the bee may eventually be paralyzed.

For both these viral diseases, any medical treatment has not yet been developed. Stricter hygienic practices and being knowledgeable of the threats is a good preventive measure until the time a concrete antiviral medicine is introduced.

Protozoan Nosema Disease

This disease is the worst-hit a colony can take, as it affects the strength of a colony as a whole. This disease infects all kinds of bees from the queen bee, to drones and worker bees.

A severe case of Nosema can cause a honeybeeBees failure to fly. Such bees are seen crawling at the hive entrances or over the top bars unable to get in.

The lifespan of a bee is extremely shorted by this infection, which can cause a severe threat to the overall strength of a bee colony. This disease is caused by the protozoan Nosema apis, which enters the gut of an infected bee. The protozoan releases spores which can easily penetrate the gut wall and live in the intestinal cells.

This causes severe nutritional depletion, as the bee is no longer able to absorb any nutrition on its own, rather it is taken over by the gut-living protozoa.

The organism produces several more spores that continue spreading throughout the intestinal wall, thereby making the bee extremely weak for lack of nutrients.

There is no way to symptomatically identify this disease in a colony, but if an otherwise healthy colony simply begins to dwindle and dead bees abound, one can go for confirmation of this disease through lab tests.

If the infection is confirmed then heating or fumigation techniques must be employed to get rid of the protozoa. The spores would still not die. And very high heat and disinfecting treatments are to be used before any new colony is introduced.

Preventing Bee Diseases

Preventing Bee Diseases

Though there is little one can do once the hive is infected, it is safe to say that prevention is better than cure. There are a few simple steps that you can take to prevent an onslaught of such deadly diseases.

Keep all your hive tools neat and clean. Use a simple disinfecting solution to lightly wipe down your tools before and after each use. Likewise, so not introduce disinfectants to the bees, let your tools dry out a bit after applying disinfectants before you use it in a hive.

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If you are using the same equipment for other colonies or for neighboring apiaries, take care to not use unclean tools between colonies, as this can carry diseases from one apiary to another.

Keep the area in and around the hive clean and tidy. It is your backyard and is open enough to attract junk and trash of all kinds, and it is but natural for us to ignore it for a little while longer.

Be it broken combs, propolis, pieces of wax, drops of honey, dead bees or brood, or some entirely different trash that you can introduce, like food and candy wrappers, stray papers or any organic wastes; keep it all away from the hive. Cleaner hive areas will ensure fewer diseases among bees.

Arm yourself with knowledge about what to look for in each disease, what kind of symptoms to identify, and what steps to take once the disease has been identified. Remember, knowledge is always power!

Our Recommendation

Check out this useful Book: Diagnosis Of Honey Bee Diseases by the United States Department of Agriculture

Animals and Pests

Similar to microbial diseases, animals and pests cause their own nuisance that a beekeeper must learn to overcome. Different insects and animals have been known to cause sufficient damage to a thriving bee colony.

Parasitic Mites

Beekeepers all over the world are of the consensus that parasitic mites are the deadliest enemies of any honeybee colony.

There are several different types of these mites, each more dangerous and deadly than the other.

Varroa Mites – Varroasis

Varroa Mites – Varroasis

These are more commonly seen in Asia. Almost all of Asia is affected by these mites. These are parasitic creatures that live both with the brood and with the adults.

In the brood cells, the varroa mites simply feed along with the larvae, thereby depriving the larva of its food and resulting in its death. In adult bees too, these mites are seen clinging tightly between the areas of their thorax and their abdomen.

These mites suck the ‘blood’ or hemolymph of the adult bee. They can be seen with the naked eye on closer inspection. Capped brood cells are opened and the brood removed gently with the help of tiny forceps and the mites are observed in the cell.

In adult bees, the bees can gently be caught and held against the light, the mites if present can be seen clinging to their mid bodies. Though broods do not survive a varroa mite attack, adult bees are seen to recover at times.

Adult bees show symptoms of weakness, flying inability and deformed wings and shortened lifespans. These mites have been known to be passed from stored bee equipment and beekeeping essentials that are put away for winter.

The mites grow in these tools and are transferred onto the bee colony. Also, colonies infected with varroa mites get killed and also cause the destruction of neighboring bee colonies.

Usually, infected bees in the early days of infection fly away to other colonies and spread the infestation to that new colony too. This causes the destruction of multiple colonies one after the other.


The best-known practices to treat varroa mites are the use of chemical agents. There are two opposing views on using chemicals to treat the mite attack.

Many prefer and even swear by the chemical treatment as the best and most effective way to quickly handle a mite attack. These chemicals may include formic acid, oxalic acid, pyrethroids, and Amitraz, etc.

Lactic acid is the mildest of them all, and one that is readily tolerated by the bees. But chemical use has several disadvantages such as honey contamination, sufficient residues in the hive elements, and the harmful effect on bees. In deference to this chemical, usage is the opposing view of hive management to effectively control the mite population.

Once you have inspected your brood cells and discovered that the cells are indeed infected by the mites, Once you have inspected your brood cells and discovered that the cells are indeed infected by the mites, now is the time to act This stage of the mite life-cycle is before it can affect the adult bees.

So action taken to eradicate the mites would be most effective in this stage only. The mites need the brood to survive, so for that, you trick the female mite to lay its eggs into a brood cell that you can simply remove and dispose of.

How you do this is by restricting an affected brood comb between solid follower boards. As the queen lays eggs and the female mite lays eggs too into the brood, you can simply remove the comb with infected mite cells along with its egg-laying female and dispose of it safely in a faraway place. Burning the comb is the best-offered solution.

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2. Varroa EasyCheck Tool

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4. Varro Mite Treatment Pack using hop compounds


Tropilaelaps mite

This mite causes very similar symptoms to those of the varroa mites. The adult bees have deformed wings and are seen hovering by the hive entrances or crawling around, simply unable to fly and perform their normal functions.

Infestation by this mite is highly impossible to control, especially in the tropical Asian regions. As a treatment agent, formic acid is sprayed onto the top bars and on the combs so that it kills the female mite and mite eggs present in the brood comb.

A few manipulator techniques are employed to trick the female egg-laying mite from furthering its egg-laying process. The uninfected broods are separated and placed in a different hive and provided a different mated queen.

The queen is caged for a few days within the hive to acclimatize it to the new bees and to allow for the brood to hatch. Then the queen is released, which now lays eggs in uninfected brood cells. The older infected brood cells are destroyed.

Tracheal Mite

Tracheal Mite
This is the Acarapis woodi mite that infests the tracheal system in the bees. All castes of bees, adult drones, workers and queens, all are prone to be infested by this mite.

Infested adult bees are known to perform their nectar foraging activities quite normally. Only very severe infestation causes them to die just outside the hive entrance. The mite enters into an adult bee’s body through the spiracles.

It reaches the thorax and invades the trachea. It begins to lay eggs every few days in the tracheal cells. Evaporating chemicals or organic compounds like formic acid or ethereal oils are known to be effective in combating this mite.

One way to identify and control any kind of mite population is to place a thin sheet of wood that has been coated with some kind of a sticky substance. Beekeepers usually use some kind of oil or grease to create a sticky surface.

This sheet is then placed under the bottom screen base under the hive. Ary mites present in the comb fall out and on the sticky sheet below. This is an effective way to identify the presence of mites and eliminate it if it’s a small population.

Small Hive Beetles

Small Hive Beetles

These beetles, though do not kill the bees directly, are known to infest the hives and spoil its stores of honey and pollen. This beetle enters the hive and lays eggs in the cracks and fissures of the hive, away from the bees.

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The adult beetles rupture the capped honey and pollen stores and consume it. The capping is essential for the honey to mature and ripen. Without capping the honey is prone to fermentation and rotting.

The beetle’s eggs and excretory materials also combine with the honey, changing both its color and taste and making it unfit for consumption.

Bees are capable of handling these beetles themselves by stinging and throwing them out to a considerable extent. But, we can help the bees along by removing the infested honeycombs and either disposing of them or extracting the honey, if it is not very much deteriorated yet.


One of the most common predators of beehives is the ants. Ants by nature are attracted to sweet things and what can be sweeter and more tempting than honey.

Ants destroy a colony completely by consuming everything within a hive. From bees, honey and brood, ants are interested in ever}’thing a hive has to offer. Not just for the bees, ants are quite a headache for the beekeepers too.

Ant bites are quite troublesome and can cause considerable pain. Ants are of several species, some very ferocious and their bites extremely dangerous causing a lot of swelling, pain, and redness. If such ants are near a beehive it can hardly be said it wouldn’t be a problem.

A few simple measures can be taken to fight the problem of ants. If there are anthills nearby, you must find and burn them. You could also place the hive on a high pedestal or a stand, and coat the bottom ends of the stand with some kind of varnish or paint to discourage ants.

Beekeepers also opt to place small cans or bowls filled with water under each stand leg. The water would need to be changed regularly to discourage the breeding of mosquitoes and one must also watch for any plants or weeds growing around that can help the ants to climb into the hive.

Regular mowing of the lawn also discourages the ants from foraging for hive structures.

Hornets and Wasps

Both hornets and wasps pose quite a threat to a thriving bee colony. As these are larger than other pests troubling the bees, these have a greater radius for searching for potential hive targets. So even if there are no hornets nests and wasps in your immediate vicinity, they can still fly about and reach your hive.

It has been noted that these insects have a limited time in which they patrol for possible beehive targets. This is a few months at the most.

For this reason, catching and killing the individual wasps and hornets is a reasonable enough method to combat their attacks.

Other methods include swinging a wide bat-like instrument in the wasp’s path so you are able to strike down more than a single wasp at a time. Another method is to make the entrance hole so small that it discourages any insects to enter except for the bees themselves.

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Wax Moths

There are two kinds of moths, the lesser wax moth, and the greater wax moth. Both are troublesome to the bees and the beekeeper.

The wax moth needs warm temperatures to thrive and so will look to settle in combs that are in the darkest of places and which lack good airflow.

The larvae of the wax moth destroy a comb completely eating away through the cells. These moths are quite persistent in that they are able to tolerate any amount of treatment They can also carry other parasites and microbes that can cause further destruction in the hive.

Treatment is through spraying the soil-dwelling biological pesticide, Bacillus thuringiensis. You can find get if from here – Its bee safe

Prevention can be through properly safeguarding hive tools and empty combs from catching moth infestations.

Correct storage practices are necessary to ensure your hardware remains safe of lesser or greater moth attacks. The best way to ensure this is to store the unwanted equipment in a freezer.

Frogs and Toads

Amphibians such as frogs and toads pose a very real threat to the honeybee colony. A frog or a toad can simply stand by a hive entrance and prey on bees that filter in and out of the hive.

They simply flick and swish their long tongues to catch unsuspecting bees. It also works in the frog’s favor that its considerably camouflaged body is difficult to spot by the bees at night.

These amphibians’ prey on the colonies at night and this makes it considerably difficult to understand what is causing a loss in colony strength.

One thing the beekeeper can do to recognize the issue is to look for dark brown dry fecal matter around the bee entrances. This almost emphatically proves the presence of an amphibian predator.

Guard bees that hover around the entrance holes become an easy target for the predators. One precautionary measure could be to place the hives at a considerable height to make sure frogs or toads cannot reach it.

Stronger and heavily populated colonies bounce back from these attacks pretty well, whereas an already depleted or weaker colony would suffer greatly.

Another precaution to take is to make the entrance hole quite small. If a predator can ease into the hive, the results could be horrific.

Apart from flicking off individual bees, a frog inside a beehive can cause great damage by its weight and leaps and jumps.

Geckos and Lizards

Reptilian predators like geckos and lizards prey on bees with quite an ease. Raised heights or stands do not present with a difficulty for these predators.

Lizards can easily scale heights and even reach difficult corners and crevices. For this purpose, there is nothing much a beekeeper can really do to deter these reptiles.

A beekeeper can try coating the bottoms of the stands or raised platforms with a Spray Lubricant.

Apart from this, maintaining the backyard well by trimming heavy bushes and mowing lawns regularly can prevent geckos and lizards from approaching the hives for fear of exposure.


Another predator that the bees are quite defenseless against are birds. Once the bees are on their way to or from their hive, before or after collecting the nectar, they stand the risk of being snatched mid-flight and being preyed upon by apivorous birds.

Although, it is of little consolation to know that the extent of damage depends upon the severity of the attack and the number of birds attacking.

One way of controlling such attacks is to relocate the hives to a less prone area. And if the area is home to several migrating birds it would be best to start a hive at a different location, or at least wait until the migratory season is over.

Bears, Skunks, and Monkeys

These larger animals are as much a danger to honeybees and beekeeping itself that certain cautionary measures are necessary even before you start a hive. Bears, monkeys, skunks, and raccoons have all been proven to have great interests in preying on hives for their honey.

Larger or taller fences around the bee yard can deter such large predators. Before starting a hive gather all the information available as to what kind of animals frequent the area, this will help you to put up your defenses accordingly.

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It is important to take all precautions possible in order to safeguard your hives.

From microbes to mammals, bees can be under attack from so many points. It is only wise to gather all the information and advice available and plan your bee yard accordingly.

Good beekeeping practices include clean and hygienic action events involving bees. Be it regular inspections, harvests, or feeding, all events must be carried out in as hygienic conditions as possible taking care to bring as little stress to the bees as possible.

Climatic Challenges

Apart from pests and diseases, bees need care against harsh weather and unfavorable climatic conditions. Cold, rain, wind, snow, and storms, all require special diligent care for the bees to come out unscathed from these conditions.


Whether it is a light drizzle or heavy rain, bees find rain highly unfavorable. There are several problems bees can face due to rain.

First, bees wouldn’t fly in the rain unless absolutely necessary. If any scout bees or forager bees are out in the rain, they would most probably take shelter somewhere until the rain thins out.

For a bee flying in the rain, even a single fat raindrop could be dangerous. One big drop is enough to inflict a stunning blow to a bee.

Even when it is a light sprinkling, the drops of water can cling to a flying honeybee and make it difficult for it to fly. A wet honeybee will not be able to flap its wings as efficiently as it would like.

It is usually seen that as bees sense an oncoming rain, they make preparations accordingly. Any bees that have gone out of the hive would try and return to the hive as promptly as possible as soon as it senses the rain.

Bees usually huddle together and form their ‘cluster,’ if rain brings a wave of chill along with it. Care must be taken to avoid any water seeping through the hive covers and into the top bars.

It would be extremely harmful if the top bars or the hive combs got wet. Apart from a destroyed comb and wasted stores of bee food, rain can also cause rot and diseases to spread in the hive.

Wind and Storms

High winds and storms can cause a lot of damage to a bee colony. Heavy winds can simply blow off the tops of the hive structures and cause the hives and the top bars to rattle with the force.

To prevent structural damage to the hive and save the bees from as much stress as possible, it is advised that you tie down the hive structure with some kind of fastenings. You could use a heavy rope or an elastic nylon belt with a clasp to secure the top and the hive.

You can also install what are known as wind-breaks near the hive in the direction that the wind is most likely to blow from. As additional support, you could tether the whole structure to a metal loop or nail on the ground or alternately you could add a pole or post beside the hive and fasten it together.

Winter and Snow

Winter is the hardest of all seasons for the bees. Freezing temperatures present a constant threat to bees.

Bees can survive for up to 41 degrees Fahrenheit. Any lower than that and the bees would die. So how do bees survive winter and what can you do to help them along?

As fall nears its end, and winter is about to set in, bees restrict themselves to the hive and stop venturing out. And, anyway, there are hardly any flowers at this time of the year to forage.

So by this time the bees have collected all the nectar available and stored all the honey and pollen they can. They will use this to get through winter. As winter sets in, bees begin what is known as clustering.

They stick to one another forming a large sphere of bees. This cluster has the queen in the center. The temperatures at the heart of this cluster can be around 80 to 90 degrees F.

The outer of the cluster can be around 45 degrees F. The worker bee sat the outer of the cluster would exchange places with the ones in the inner circle so that the outer bees don’t get too cold.

If the temperatures outside the hive continue to drop the bees tighten their cluster, drawing each other in, so that they are able to heat their bodies and the whole colony as a result, quite effectively.

Occasionally, on days when the weather is a little warm, the bees may venture out to dispose of their dead and discard their wastes.

Bees are very hygienic, and they do not defecate within their hives. But winter forces them to do so, as venturing out would most assuredly kill them. So they make use of such warmer days to clean their hives.

If they are unable to clean the hive, then it would be very dangerous for them, as this can cause a lot of diseases and take the already climbing death toll higher in winter.

The main goal of the bees throughout winter is to keep the queen safe and warm. They do this by constantly shivering and flapping their wings continuously.

This constant movement naturally requires a lot of energy, and this is where the honey reserves come up. It cannot be sufficiently stressed how important it is to leave an adequate amount of honey within the hive before the winter approaches.

It is best to not harvest any honey very close to winter.

It is equally important to feed the bees in the early spring. As is obvious by the time spring arrives and temperatures increase, the reserved honey would have been all but used up.

Though the bees would venture out as the temperature becomes warm, still it is wise to leave a little sugar syrup or perhaps a little bee fondant to help push the bees toward gaining back their strength and go out foraging.

As a safety measure during winter, you could place bales of hay or straw or some such insulating material around the hives to protect the hives from harsh winter winds.


Though bees are more prone to tolerating high amounts of heat, bee species in the Americas or other colder regions are genetically suited for pleasant sunny weather.

Extremely high temperatures can cause the bees to be dizzy and lose flight navigation. But this is only in extremely hot temperatures for those particular areas, like around 120 degrees F.

If you are in an area that can face such temperatures, you could very slowly either move the hive into a nearby shade with partial sun or else add a temporary shade over the hive that you can lower later on when the temperatures are pleasant.

It is important to consider and be aware of all the dangers weather and climatic conditions can pose to your bee colony.

You would naturally be well aware of how climate changes in your area and how frequently this happens. If you are armed with the knowledge of potential dangers, you can make wiser decisions and take better steps to protect your bees.


1. Chalkbrood disease in honey bees

2. Identification of chalkbrood disease pathogen Ascosphaera apis in Apis cerana cerana 

3. A novel strain of sacbrood virus of interest to world apiculture