Index
Honeybees ‘self-medicate’ when infected by some pathogens
Honeybees are fighting against Varroa
The remarkable shelf life of Honey 2014
Return of the British Black bee 2013
Secrets of the honeybee bite October 2012
HONEYBEES ‘SELF MEDICATE’ WHEN INFECTED BY SOME PATHOGENS
Researchers from North Carolina State University have discovered that honey bees ‘self-medicate’ when their colony is infected with a harmful fungus. They bring in increased amounts of antifungal plant resins to ward off the pathogen. The colony is willing to expend the energy and effort of its worker bees to collect these resins. This behaviour must have evolved because the benefit to the colony exceeds the cost of expended energy.
Wild honey bees normally line their hives with propolis. This is a mixture of plant resins and wax that has antifungal and antibacterial properties. The researchers found that, when faced with a fungal threat, bees bring in a great deal more propolis and they also physically remove parasitized larvae that the fungus was using to create fungal spores.
Resin collection and use by honey bees, as well as resin use across the animal kingdom is possibly a relatively widespread trait. Its use as a mechanism of social immunity in bees and ants is complex, involving direct effects against parasites and more indirect effects on individual immunity. Although self-medication by honey bees and ants has been discovered, it is possible that this phenomenon is more widespread in insects than previously.
Bees can sometimes distinguish harmful fungi from harmless ones, since colonies do not bring in increased amounts of propolis when infected with harmless fungal species. Instead, the colonies rely on physically removing the spores.
Resin foraging is relatively rare, particularly in European derived bees. Domestication of honey bees has resulted in a reduction of resin collection, likely because beekeepers have selected against its use since the presence of large quantities of sticky propolis often makes opening hives more difficult.
There may be a lesson here for domestic beekeepers because now we know that this is a characteristic worth promoting because it seems to offer the bees some natural defence.
HONEYBEES ARE FIGHTING AGAINST VARROA
The parasitic mite Varroa destructor is a major contributor to the death of honey bee colonies.
Scientific research in a journal published by BioMed Central Ltd, discovered that honeybee larvae, which have been parasitized by the mites and are often diseased, contain specific proteins. These proteins are also found in the antennae of adult honey bees.
In damaged larvae, transglutaminase, a protein involved in blood clotting, increases the response to a stimulus. Other proteins are involved in the process of smelling and in signal transduction wikipedia.org/wiki/Signal_transduction
These proteins are associated with uncapping brood cells and the removal of larvae.
The proteins encourage hygienic behaviour of the adults by driving them to find and remove infected larvae from their brood cells and dispose of them outside the hive. Mites are often in the cell with the infected larvae so removal reduces the number of reproductive mites in the hive.
To improve their colonies, beekeepers try to breed bees with traits such as enhanced honey production, placidity and winter survival. The researchers have now found a set of proteins which could be used to select colonies with increased hygienic behaviour. Varroa are gradually becoming resistant to available drugs so this would provide a natural way of potentially ensuring survival of the species and increased honey production.
THE REMARKABLE SHELF LIFE OF HONEY
Archaeologists excavating Egyptian tombs have found pots of honey, thousands of years old. It was unspoiled and could be eaten, without preparation, as if it were just harvested from the honeybees. Honey can remain preserved in a completely edible form if it is stored correctly and its longevity also lends it other properties, mainly medicinal.
Honey is a sugar. Sugars are hygroscopic which means that they contain very little water in their natural state but can readily absorb or attract moisture from the air. Honey is also naturally extremely acidic.
If the honey is sealed in a jar, the combination of minimum water and the acid will kill off almost anything that wants to grow there. Very few bacteria or microorganisms can survive in an environment like that. There is no real need for the *sell by date* to be on the label.
There is a special alchemy that goes into honey. Nectar collected by honeybees is naturally very high in water – anywhere from 60-80 percent but the bees remove much of this moisture by flapping their wings over the nectar. Bees also have an enzyme in their stomachs called glucose oxidase. This enzyme mixes with the nectar, breaking it down into two by-products: gluconic acid and hydrogen peroxide. Hydrogen peroxide is the next thing that goes to work against all the bad things that could possibly grow. The bees place this mixture in the honeycomb cells and seal the cells with impermeable wax.
For these reasons honey has been used for centuries as a medicinal remedy. Because it’s so thick, rejects any kind of growth and contains hydrogen peroxide, it creates the perfect barrier against infection for wounds. Ancient Egyptians used honey medicinally – making ointments to treat skin and eye diseases and to cover a wound or a burn because nothing could grow in it. While it’s drawing water out of the wound, which is how it might get infected, the honey is letting off very minute amounts of hydrogen peroxide. This actually promotes healing. Is was and still is, a natural bandage.
When honey isn’t sealed in a jar, it absorbs moisture and will spoil (not immediately) so keep the lid on tight. Thus are the secrets for honey’s long shelf life.
RETURN OF THE BRITISH BLACK BEE 2013
Photos above
left & right British Black Honeybee Bees: Hairy with thick black stripes/thin yellow bands
middle European Honeybee: Golden with brown/yellow bands
Native Black honeybees have been found in remote parts of Wales, East Anglia and as far south as West Sussex. It was feared that most of them had died out in all but the remotest areas of northern Britain. Biological, historical and archaeological evidence shows that honey bees from around 4,000 years ago up until the 19th century were genetically the dark European honey bee (Apis mellifera mellifera).
British Black bees are much darker and have evolved thicker, longer hair and a larger stocky body than their southern European cousins, in order to help keep them warm in our cooler climates. They also have a shorter breeding season to reflect the UK’s summer. This means that colonies have smaller populations going into winter thus needing less food to survive, and also have fewer mouths to feed during a cold spring snap.
Some experts suspect that UK’s changing weather is the main reason for the reduction in honeybees by up to 30 per cent in recent years. Erratic weather, particularly wet summers, parasites, pesticides, disease, starvation and bad beekeeping have all been implicated in honeybee deaths.
From about 1814, small numbers of Italian bee imports took place, often for experimental purposes. This had very little effect upon the native bee population until the early 1900s. From this time onwards there were major imports of foreign bees. Between 1916 and 1925 the British black bee was rendered virtually extinct in England and Wales by Acarine mites. This outbreak was called the Isle of Wight disease. Some parts of Ireland and Scotland were less severely affected. In Scotland the Black bee numbers were still significant up to the late 1960s.
Major importation continued from around the world. Beekeepers favoured the Italian honeybee as it is seen to be more hardworking (therefore more honey) and placid. Black bees do have an aggressive reputation but beekeepers say they can be docile if cared for properly. These imports have had a severe and adverse effect on the genetic mix of our honey bee and also introducing pest and diseases. Although natural selection still favours dark bees, many of the major genetic advantages of our original native dark bee have been lost. Strict controls now apply to the import of honeybees into the UK but the bee population is still being topped up by imports of largely Italian style queen bees (Apis mellifera).
The Bee Improvement and Bee Breeders Association ( Bibba) reasons that pure-race native bees are desirable for biodiversity, and in 1997 began a project to conserve the black bee. As yet only 1% of the 250,000 hives across the UK today are likely to house black bees. Our indigenous specie of honeybee has evolved characteristics that are well suited to UK’s climate and if bred could hold the key to reversing the dramatic decline of our honeybee colonies. It is hoped that this hardy insect will be less vulnerable to bad weather, mites and disease than the southern European honeybee subspecies used by many UK beekeepers.
In 2009 Bibba, aided and funded by the Co-Operative Group, unveiled a scheme to reintroduce black bees. Researchers will map wild populations of the bee across the UK so they can be caught and bred.
The British Beekeepers Association are also encouraging its 22,000 members to do local breeding rather than simply importing bees from southern Europe.
If you see a black bee, please email a picture of it, along with details of when and where it was taken, to: campaigns@co-operative.coop. This will help greatly in the research.
SECRETS OF THE HONEY BEE BITE October 2012
Honeybees can bite as well as sting and researchers have discovered that their bite contains a natural anaesthetic.
The anaesthetic is 2-heptanone (2-H), a natural compound found in many foods and also secreted by certain insects. Until recently it was thought it was either a honeybee alarm pheromone that triggers defensive responses, or a chemical marker signalling to other foraging bees that a flower had already been visited.
Research shows that the anaesthetic paralyses small insects and mites bitten by bees for up to nine minutes. This enables the bee to eject enemies from the hive and is a very effective defence against pests, such as wax moth larvae and varroa mites, which are too small to sting. Beekeepers have long spoken of the grooming behaviour of honeybees in helping to control varroa populations. Now this grooming behaviour can be interpreted as biting behaviour.
2-heptanone may not only help honeybees fend off pests such as wax moth and the parasitic varroa mite, but it also has great potential as an anaesthetic for use in human medicine. The surprise findings were discovered by a team of researchers from Greek and French organisations in collaboration with Vita (Europe) Ltd, the UK-based honeybee health specialist.
Read about the research here
www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0047432