Honeybees of South Africa
South Africa is home to two sub-species or races of honeybees which are indigenous to the country: Apis mellifera Scutellata (or “African Honey bee”) and Apis mellifera Capensis (or “Cape Honey bee”).
Location:
Map 1 The distribution of South African honey bee subspecies. Drawn by Dr F Démares
The Cape bee is generally confined to the western and southern Cape regions and has strong association with the Fynbos biome. Running in an imaginary line between Vredendal on the western Atlantic coastline across to Willowvale on the eastern Indian Ocean coastline describes it northern limits.
A hybrid zone between the two regions divides the two subspecies with the African honey bee covering the region to the north of South Africa and further extending into East Africa.
Apis mellifera scutellata – African honey bee
The African bee is an aggressive bee with a hardy strain and capable of producing large crops of honey. It has more of a yellow striped abdomen compared to A. m. capensis.
Only the queens are fertile; worker bees are infertile when the queen is present. The queens are prolific layers and during strong honey flows the colony builds up rapidly However, worker bees have the ability to lay unfertilised, drone eggs.
African honey bees, most of them form South Africa, were introduced to the Brazilian bee industry in the mid 1950’s and immediately adapted to its surrounds, hybridizing with the introduced honey bee subspecies of European origin, although 70 years later large parts of the honey bee population in Americas has “purged” the European genes. These bees became misleadingly known as the infamous “African Killer Bees” which have steadily moved northwards up into the United States
Apis mellifera Capensis – Cape honey bee
The Cape honey bee tends to be a more docile bee, although can also become aggressive when provoked. Work by Gerald Kastberger showed that docility and aggression is rather a colony characteristic rather than a subspecies feature.
The Cape honey bee can be distinguished by a number of features; one of them, although a rather inconclusive one, is a darker colouration compared to the African honey bee. This is the reason why some people referred to them as “black bees”, however dark abdomen in honey bees can be caused by age and temperature during the brood phase and other features should be considered to correctly identify the subspecies.
It has a unique characteristic in that colonies of the Cape honey bee can have worker bees (females) that have the ability to produce male and workers that produce female offspring. The ability of producing female offspring is also linked to the fact that these workers can produce pheromones which makes them smell like a queen. As a result, one could observe other workers treating these queen-like smelling workers like a queen and forming a retinue around her. The production of females enables them to re-queen in the case a colony has become queenless.
The downside of this characteristic is that it has the ability to parasitise colonies of all other honey bee subspecies, in particular scutellata colonies. Capensis laying workers invade and subsequently begin to lay their own eggs, challenging the hosts queen’s ability to control the colony and as soon as the colony is captured by the Cape honey bees, the workforce dwindles down and will collapse.
Signs of a Capensis invasion are: multiple eggs observed in cells, (may even be laid on top of pollen), raised capping of brood cells, reduced activity within the hive, and non-aggressive bees. A ring of workers (retinue) around another worker. Other features, which require dissecting the worker in question can be used to distinguish between the subspecies.
The two South African subspecies Apis mellifera scutellata and A. m. capensis Picture C.L. Laing
A healthy colony of A.m. scutellata
(source: P. Kruger: Department of Entomology, University of Pretoria)
Scutellata worker bees with queen. Spot the braula (bee louse) on the worker bee next to the queen.
(Source: P. Kruger: Department of Entomology, University of Pretoria)
Capensis worker bees with queen. Note the braula (bee louse) on the queen and worker bees attempting to clean her.
(Source: Internet – Unknown).
Cape bees and African bees together. The cape bees have darker bodies whereas the scutellata bees have orange bodies.
(Source: P. Kruger: Department of Entomology, University of Pretoria).
A colony of Cape bees. From a distance they are hardly distinguishable from African bees. ; but if you look closer you can see they are “black bees”.
(Source: K. Crous: Department of Entomology, University of Pretoria)
Bee Diseases, Pests and Parasites
Dr Hannelie Human and Prof Christian Pirk
Honey bee populations worldwide, have to deal with pests, parasites, pesticides, land use, climate change and other stressors. These factors, and some home-grown ones like the capensis social parasite, play a role when it comes to the health of the South African honey bee population, as well as all the potential negative implications for the beekeeping industry of South Africa.
These different threats also pose a threat for the agricultural sector and biodiversity, since both depend on pollination services. Since only a small part of the honey bee population in South Africa is kept by beekeepers, and beekeepers “refill” their stock with swarm catching, the wild population constitutes an essential resource, which has to be sustainably utilized.
It is essential for any beekeeper to be able to recognise various honey bee pests and diseases. Early detection of any problem allows for prompt action and thus the prevention of serious outbreaks and subsequently economic losses. Karl von Frisch, winner of the Nobel Prize in 1973 for his work on the honey bee dance language, said the following:
“Thus we see, after traveling a long way, that we have not reached the end of the road but stand instead at the threshold of new problems”.
Healthy brood
In healthy colonies the brood combs usually have a compact pattern. Almost all the cells from the centre of the comb outwards contain either eggs, larvae or pupa. Cappings are convex and tend to have a uniform colour.
Unhealthy brood
The brood comb of diseased colonies often has a spotted pattern (pepperbox appearance). The cappings may appear sunken or even punctured and the colour can be darker. Sometimes dried out remains are present on the bottom or sides of cells.
Bacterial diseases
American foulbrood (AFB)
This infection is caused by the spore-forming bacterium Paenibacillus larvae. It is considered to be most devastating honey bee disease and can result in severe colony losses. It affects only the brood and is highly contagious and extremely difficult to eradicate due to the resistance to heat extremes and chemicals. The bacterial spores can remain viable for up to 60 years.
Infected larvae die and a distinctive foul smell develops. At this stage ropiness can be demonstrated; the remains can be drawn out as a string (i.e. extend 10-30mm). The dead larvae then dry out to dark and highly infectious scales that tightly adheres to the cell wall. Infected colonies have scattered and uneven brood patterns with dark, greasy looking, sunken cappings.
AFB infected frame showing spotty brood pattern and ropiness test. If the contents are drawn out further than 20mm this indicates that AFB is present (Pictures R. van Zyl)
European foulbrood (EFB)
This brood disease is caused by the non-spore forming bacterium Melissococcus pluton. It affects open brood and is common during spring when brood rearing is at its height. Colonies may be severely weakened. Infected larvae appear coiled/ twisted in their cells with a pale yellow to brownish colour and normally die before their cells are capped. Sometimes one can detect a sour odour. EFB is considered a less serious disease than AFB but high losses have been recorded.
EFB infected larvae are twisted. Pictures P. Kryger
Fungal diseases
Chalkbrood
This brood disease is caused by the fungi Ascosphaera apis. The disease is common in spring during cooler, wet weather. The spores germinate in the gut of larvae and is followed by mycelial (cotton-like, whitish fungal) growth after being sealed as pupae.
After death the larvae become mummified with a chalk-like appearance; the colour change from white, then grey and finally black. Uncapping of cells of dead larvae by workers make this visible. Workers sometime remove them and deposit them at the hive entrance. When combs are shaken the mummified larvae make a rattling sound.
Infected colonies are rarely killed but can be weakened with higher susceptibility to other pests and diseases and subsequently reduced honey crops.
Chalkbrood larvae with fungal growth and mummies taken from brood cells (P Kryger and U Strauss)
Stonebrood
This disease is considered to be extremely rare and is caused by the fungi Aspergillus flavus and A. fumigatus.
Stonebrood is pathogenic to larvae, pupae and adult bees and the effect on colonies is not well understood. Early stage of stonebrood infection is difficult to detect but after death larvae become very hard and are difficult to crush. The spores can cause respiratory diseases in humans and other animals.
Example of stonebrood. Figure P. Kryger
Nosema
Nosemosis is a common disease of adult honey bees, caused by the intracellular microsporidian parasites Nosema apis and N. ceranae. It appears as though N. ceranae is more damaging than N. apis, and kills infected honey bees faster than N. apis. Colony losses have been linked with severe N. ceranae infections.
Infected bees and queens suffer from severe dysentery, subsequently resulting in starvation and a shortened lifespan with queens ceasing to lay eggs.
This can result in reduced colony health and performance; ultimately in the colony dying. Heavily infected bees have swollen and greasy looking/ shiny abdomens and are unable to fly. They may crawl at the entrance or stand trembling on top of the frames. There may be dysentery spots on the hives, frames and landing boards with dead bees at the entrance.
Visible symptoms of Nosema infection with faecal matter on frames and on hive. Picture P. Kryger
Viruses
Honey bee health can be dramatically affected by viral diseases, their physiological state influencing the development of an acute or chronic infection. Trophallaxis (mouth-to-mouth feeding) aids in transmission between colony members (from eggs to workers to the queen). Viruses have been reported in honey and pollen and sharing of floral resources can also result in transmission between pollinators and are furthermore transmitted from wild to managed honey bees and vice versa. Varroa mites are vectors for several viruses. Viruses may be present in hives without any clinical symptoms that only becomes visible after stressors (including agrochemicals) have weakened the colony.
Viruses cannot easily be distinguished from each other due to a lack of reliable symptoms and they have to be identified through molecular tools. The exception is Sacbrood (SBV) and Deformed wing virus (DWV). There are at least 24 honey bee viruses identified and some of the more common ones are: Acute bee paralysis virus (ABPV), Apis mellifera filamentous virus (AmFV), Black queen cell virus (BQCV), Chronic bee paralysis virus (CBPV), destructor virus-1/DWV-B, Israeli acute paralysis virus (IAPV), Kakugo virus, Kashmir bee virus (KBV), Lake Sinai viruses (LSVs) and Slow bee paralysis virus (SBPV).
Acute bee paralysis virus (APBV), Israeli acute paralysis virus (IAPV) and Kashmir (KBV)
APBV and KBV are related viruses that commonly appear in apparently healthy adult bees. These viruses are highly contagious and its virulence is made possible through its association with the Varroa mite that carries the mite both externally and internally.
When more and more bees become infected, they will also facilitate the spread of the virus. Bee losses that were reported from the USA are related to these viruses.
Brood removal of colony with ABPV. Picture P Kryger
Hairless bees, here due to Acute Bee Paralysis Virus. Dark colour due to immune response. Picture P Kryger
Honey bee larvae affected with ABPV; symptoms can be confused with that of EFB. Picture P Kryger
Deformed wing virus (DWV)
Deformed wing virus (DWV) and its vector, Varroa destructor, is considered to be a serious threat of honey bees. It is the “most well-known, widespread, and intensively studied insect pathogen in the world”.
This virus causes bees to grow ragged wings that are incapable of flight. These bees die off naturally or are removed from the colony within 2-3 days after emergence.
Bees with DWV. Picture P Kryger
DWV and melatonin from immune response giving dark colour Picture P Kryger
A honey bee with typical wing deformities caused by DWV – note the shriveled wings. Wings may also be completely absent or reduced to stumps. Picture P Kryger
Sacbrood
Sacbrood is a common vial brood disease caused by the virus Morator eatotulas. Infected larvae die and tissue disintegrates into a brown watery solution held together by the larva’s outer skin. The virus is probably fed to larvae by nurse bees and thereafter contaminates the cleaning bees.
This disease does not cause serious colony losses and may appear at any time during brood rearing season although it is most common during the first half of the season and usually subsides after honey flow starts.
Sacbrood virus. Picture P Kryger
Honey bee larvae showing typical symptoms of sacbrood virus Picture P Kryger
Parasites
Parasitic Cape bee (Apis mellifera capensis)
Capensis parasite invasion of scutellata colonies results in the dwindling of the host worker force. These parasitic workers are able to lay eggs that give rise to female offspring, which perpetuates the parasitic life-cycle. Evidence suggests that their ability to mimic the queen’s pheromones is one reason for their success in taking over a colony.
It is important to understand that these cape workers do not contribute to any activities, such as foraging, hence these colonies become unproductive and eventually starve to death, serving only as a source of infection for other uninfested colonies in the vicinity.
The spread is most likely is facilitated by hive inspections/ beekeeping management. Multiple eggs in cells is a tell-tale sign of infection. See descriptive figure for signs of infection.
a) The typical dark colour of a parasitic cape bee b) A black cape bee is shown on the left, with a yellow A.m. scutellata worker on the right c) A cape bee being attacked by scutellata workers d) Spotted brood pattern which is typical of a capensis infestation e) Multiple eggs in cells suggest that cape bees might be present f) Capensis brood often present with raised cappings. Pictures C Laing
Apiary lost due to capensis. Figure Douglas Bee Farms
Varroa destructor
These external parasitic mites live and feed on adult bees but mainly reproduce and feed on developing brood. The mites can be seen with the naked eye as a red or brown spot about the size of a sesame seed.
Examples of the damage caused by these mites are morphological deformation especially wings, reduced lifespan, weakening of the immune system and transmission of secondary diseases (e.g. bacteria and viruses).
Varroa mites are one of the most serious pests of European bees worldwide; if infested colonies are left untreated by the beekeepers, the mites will kill the colony within 3 to 4 years. When the colony shows symptoms, it is commonly called the parasitic mite syndrome.
Too much brood for number of bees Varrosis Picture P Kryger
Varroa on bees. Picture P Kryger
Varroa on brood. Picture P Kryger
Varroa destuctor Picture P Kryger
Varroa and acute bee paralysis virus. Picture P Kryger
Varrosis final stage. Picture P Kryger
Honey bee tracheal mite (HBTM)
Tracheal mites, Acarapis woodi, are endoparasitic mites that only parasitize the adult bees, affecting their trachea or respiratory system.
The disease is called the Acarine disease/ Acariosis. Heavy infestation results in sick bees that do not work as hard or live as long as healthy bees, subsequently causing weakened colonies and increased mortality.
These mites can’t be seen with the naked eye and are difficult to detect. Mites pass quickly from bee to bee and once established, rapidly form colony to colony.
Picture 7. Tracheal mites in honeybee trachea.
Pests
Braula or Bee louse
This small wingless fly, Braula coeca, measures 1.6×1.2mm and is found on the thorax of workers and queens. They are light brown in colour and are often confused with Varroa mites.
When the queen is fed, they move to her mouth and steal some of her food. Their eggs look like small white spots and are laid on cappings and the top of cells. When the bee has emerged, the bee louse starts tunnelling under the cappings to feed on wax, pollen and honey. This makes comb honey less attractive.
Although they are not a major pest it has been suggested that large numbers on the queen could reduce her efficiency.
a) Adult Braula. Although they are similar in size and colour to Varroa mites, the body is more spherical (as opposed to flattened) and they only have six legs. b) Braula eggs appear as white spots on cappings and the top of cells. Pictures U Strauss and C.L. Laing
Braula and Varroa on bee larvae. Picture U Strauss
Bee tachinid
This fly, Rondanioestrus apivorus, is larger than the common housefly and more flattened. Its wings have black venation, and the abdomen is grey and square-like. The body of the fly is covered in long, spiky hairs.
The fly sits close to the hive entrance and when a bee arrives at the entrance it will take flight and lightly touch the abdomen of the bee, thereby depositing a single egg on the bee.
The fly larva penetrates the abdomen of the bee feeds on the haemolyph and grows inside the bee. Within four weeks it will be large enough to occupy the entire abdomen. The bee then dies and the larvae leaves the abdomen at the posterior end and burrows into the ground to pupate.
A fully-grown larva of the bee tachinid. The black spots are spiracles used for breathing. Picture C Laing
Small hive beetle (SHB) – Aethina tumida
Small hives beetles are endemic to sub-Saharan Africa. It appears that our honey bees have co-evolved with these beetles and is not considered a threat. Beetles are dark brown to black in colour and their average size is 3x7mm.
Small hive beetles feed on bee brood and food reserves and reproduce within hives, but as soon as the larvae reach the wandering stage, they crawl out of the hives to pupate in the soil, (within 20 m of the hive). However, these beetles can act as vectors of honey bee viruses and bacteria and that is a matter of concern
a) Small hive beetle on the hive lid, b) imprisoned in a propolis cell, c) honey bee chasing a small hive beetle and d) small hive beetle being balled by a honey bee. The bees do attempt to sting the beetles, but it is not effective. Pictures C.L Laing
Small hive beetle larvae
Large hive beetle (Cetoniid beetles)
The beetles are black, measure 20x12mm and are active from March to November. They preferably feed on brood, but will also feed on pollen and honey.
Heavy infestations can lead to significant brood loss and even absconding by the colony. The beetles are attracted by the smell of honey and can often be seen settling on/close by colonies while the colonies are opened and being worked with.
Deaths head hawk moth
The moth’s, Acherontia Atropos, name is derived from the skull-pattern on its thorax. The moth is large, with a wingspan of about 100mm. When handled or disturbed, the moth emits a squeaking sound. It is thought that this sound mimics the piping sound made by a queen honey bee, thereby discouraging aggression by the bees.
Eggs are laid on the leaves of various plant species and larvae pupate in the soil. Adults will enter the hive to feed on honey, but are harmless and do not cause damage. The moths are sometimes killed by the bees and encased in propolis.
Death’s head hawk moth, the characteristic skull pattern that gives the moth its name. Picture C.L. Laing
Wax moths
Two species of wax moths are found in South Africa, Galleria mellonella (greater wax moth) and Achroia grisella (lesser wax moth), with the greater wax moth being the most destructive.
Wax moths are known to cause serious damage in hives after the bees have been driven out or in comb stores. They act as cleaners of the empty nests. Burrowing larvae leave silk trails behind and can, in extreme cases, destroy the entire comb, with only a matted mass of silk and other debris remaining. Moths’ larvae gnaw wooden material as they get ready for pupation and their cocoons are very sturdy.
a) Adult greater wax moth and b) cocoons of the wax moth larvae. Debris and faeces are usually incorporated into the cocoon. Picture C.L Laing
The silken tunnels produced by wax moth larvae. In heavy infestations the comb will be completely destroyed with only the silk remaining. Picture C.L Laing
Ants
Ants can be a major pest of honey bee colonies. They will carry off both eggs and larvae, and also feed on the honey.
Severe ant infestations could cause a colony to abscond.
A hive stand placed in tins filled halfway with used oil. Note that all surrounding plants must be trimmed so that they do not form a bridge to the hive which the ants can use to avoid deterrents. Picture C L. Laing
Pesticide poisoning
Pesticides can impair different physiological processes, development and negatively affect different behaviours of honey bees.
Any of the pesticides (mentioned below) can kill significant numbers of bees if the dosage is too high or if the pesticides are applied in a bee-unfriendly way.
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