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This is an extract from an article which appeared in the Farmer's Weekly, South Africa. Author Clarke Gibbons
What happens when you combine a Langstroth with top bar and a traditional African log hive? You get an easy- to use, economical unit which solves the problems of keeping tropical African bees. Tim and Crispin Jackson of Wensleydale farm at Skurweberg near Pretoria, Souith Africa, and have developed a new concept in beekeeping after spending several years experimenting with traditional African hives. "We had been keeping bees for many years in Langstroth hives when Mr Paul Magnesson of the Plant Protection Institute in Pretoria persuaded us to try a top bar hive, saying that these are cheaper and easier to use than the Langstroth. We made up a number of hives according to his basic design, and found that it gave certain advantages over the Langstroth hive. Since then we have been experimenting and modifying the design to overcome the limitations of the top bar hive." Two basic designs of Top-bar hives originate in Kenya and Tanzania. They are almost the same, both being in the form of a horizontal box, with a row of wooden bars placed side by side along the top of the box to carry the honey combs. The only difference being that the Kenyan TBH has sloping sides. "The most serious problem is that honeycomb is fastened only to the top bar, and breaks off very easily. With a frame, you can safely turn the comb to any angle for inspection," says Crispin. "Combs can break off the bars when hives are being transported, and you can't use a machine to extract the honey." In trying loose frames, they decided on a new design. "We needed movable frames with wires for transporting our colonies and for mechanical extraction of the stored honey, and we also needed something which would be easier to assemble," says Crispin. "We found that the Langstroth frame is too wide for African bees. "Italian and other European bees need a comb spacing of 35 mm, whereas the smaller African bees require a spacing of 31.9 mm. In a stacked hive, beespace of between six and eight mm must be left between the brood frames for the bees to get to the supers,. but there is no need for this in a top bar hive," says Crispin. "We have reduced the tops of our frames to 32 mm wide. They are 490 mm long to fit into standard extractors, and we can also put them into Langstroth brood boxes when manipulating a colony.. We simplified construction of the frames by using 16 mm dowel rods for side bars, and 8 mm dowel for the bottom bar. Round holes are drilled, the relative rods fit tightly into these and are glued in place. They are the strongest frames in commercial beekeeping." There is space below the frames for bees to move freely on the floor of the box. This encourages them to build comb right down onto the base bar. Experiments with various shapes of wax foundation indicate that a sine wave shape promotes a well-filled frame with good attachment to the bottom bar. "This design of frame allows for easy uncapping," says Crispin. "The bees form a very level comb in these frames. We uncap with a pair of parallel hot wires, l6mm apart. These are slid up the side bars and give a neat result.." They tested a range of materials, thicknesses, densities and hive sizes to make a lightweight, efficient and durable hive. "Thick wood was too heavy, whereas thin wood and masonite gave poor insulation. Rigid plastic degrades too quickly under the fierce African sun, but waxed cardboard offered certain advantages, and this in turn led us to the sheets of corrugated plastic we are now using and have registered." This material is made of
extruded polypropylene plastic incorporating 3% carbon black with a life
expectancy of eight to 10 years under the harshest ultraviolet conditions.
It is similar to carton cardboard, having two flat sides separated by
corrugated flutes. It has excellent insulating properties, and is very
light. The sheets are cut to shape, and lines are scored for the folds
to form the box, using a simple wooden jig. A wooden frame keeps the shape
and carries the weight of the frames. Handles 1.9cm wide and 3.2 cm deep are glued along the length of the box below the support shelf. Each is 1 metre long, protruding 10 cm past the ends of the box with a hole 3 cm from each end for suspension wires. The hives are suspended from trees or other support by four wires attached to the handles. This means the hives can be placed at any height. "Studies in the USA indicate that it is best for the bees to have the entrance of the hive at about four metres above the ground," he says. "Having the hives at this height overcomes several problems, for example that of vegetation blocking the entrance. It is difficult for vandals to damage the hive, and impossible for honey badgers. The problem of ants is easily overcome by smearing the support wires with grease. Hives suspended from trees also have the benefit of shade, and wind protection. Where hives are placed for pollination, if they are high above the ground, there is less danger of problems arising with farm workers getting stung. Cross braces, 46 cm long, are placed across the end walls of the box, screwed to the handles. The lid is attached to one of the handles and folds out of the way when working. A row of short pieces of dowel on the other handle hold the lid closed. The lid does not rest on the wooden frames but on the longer end panels of the hive, giving a ventilation gap, which allows for circulation of air above the top bars, dissipating heat and assisting in moisture evaporation through the relatively porous pine timber. Most beekeepers in South Africa work on a migratory system, following the honey flow to various parts of the country. There are various problems in moving conventional hives with supers on, not least of which is the need to keep the stacks of wooden boxes intact. With this hive most of the problems are eliminated because it is a lightweight, continuous structure, equal to a brood chamber and 2,5 supers. The hives are easily closed by lifting the flaps at the entrances, and sealing them with tape. Complete with bees and empty frames these hives weigh only about 6,5 kg, as against 30 kg and more for a Langstroth hive. The new hive is much cheaper than a traditional Langstroth hive, selling at around R200 as against a Langstroth of equivalent size costing about R440. These hives are easier to transport than Langstroth hives, and are easily stacked, he says. "We have not stacked higher than five hives but the inherent strength provided by the 16 mm dowel should allow more to be stacked." The Jacksons say that like
many other users of top bar hives, they have found that the bees in these
hives are calmer and easier to manipulate than similar sized Langstroth colonies
in the same apiaries. "We lightly smoke all entrances with a two minute
waiting period to allow the bees to start drinking from open cells. While
waiting we fold back the lid to expose the top of the frames. The back frames,
furthest from the brood area, are removed individually. Once these are removed
and the rear-most part of the swarm and honey storage area is reached light
smoke can be applied to make them move to the opposite side of the frame.
Smoke does not enter the hive cluster to disturb the bees unnecessarily. The
frame is inspected, and if it is partially drawn, uncapped, raw nectar ready
to be evaporated it is placed at the back of the hive as all the capped honey
will be found between this frame and the brood frames. The capped frames are
removed after gently smoking the side facing the beekeeper. They are then
loosened, and the remaining bees are shaken or brushed off the comb. The bees
shaken off the combs land on the floor of the hive and run toward the darker
section of the hive in the still-covered brood area. In this way they allow space for backwards movement of the brood cluster. "By removing the old brood comb we bring the whole brood cluster continually forward and maintain an area for the brood area to expand, and by regular harvesting we maintain sufficient honey storage area. Swarming has dropped to less than 5% per annum, from an average of 12% in Langstroth hives. In one apiary we have not opened the brood cluster for two years, other than removing old disused combs. A major advantage of the
new hive, says Crispin, is that it offers a practical solution to the Cape
Bee problem "Beekeeping on the South African highveld experienced drastic
changes as a result of the introduction of a sub-species of honey bee to the
area. The native Apis mellierra scutellata bees are hard working and profitable
in commercial applications. This is also true ofApis mellifera capensis, a
strain which presents a serious problem .The Cape laying worker is the only
bee that can lay fertile female eggs without being mated by a drone. When
the two strains hybridise and the progeny is then stressed, for example when
colonies are transported, the phenomenon of the "Capensis laying worker"
can occur, leading to a complex degeneration of the social structure of the
A.m.scutellata X capensis hive and the death of the swarm, because there are
too many pseudo queens for the colony to sustain. To prove his theory, he set about forcing a discrete cluster in one of the new hives. A strong, established swarm was opened and the two rear frames removed. These were replaced with two frames of a mixture of nectar, stored pollen and young bee-covered brood, taken from the brood cluster. This left a gap of eight empty frames between the back two frames and the swarm. The hive was closely monitored and within five days pseudo queens had infested the whole swarm, and multiple eggs were being laid in open cells on the back frames. The group of bees which had clustered on the back frames in the cold night temperatures were queenless as the A.m. scutellata queen had stayed in the brood area at the front of the hive. This led to a drop in the pheromone level of the back cluster and subsequent laying worker infestation. The bees seem very happy with the new hives, he says. "We have had wild swarms occupying the hive boxes in preference to standard Langstroth and five frame trap hives."An important reason for this, he believes, is that the plastic is conducive to evaporation. "When bees harvest nectar they have to evaporate it down, taking out about 80 per cent of the moisture because water content will ferment the honey. Bees will only collect as much nectar as they can evaporate down at any time. If they can process more nectar, they will collect more. With plastic sheeting instead of wood the relative humidity in the hive is reduced and more honey will be produced. This is particularly true in the tropics where wooden hives become impregnated with moisture. When it gets hotter this is released into the hive, limiting evaporation. With the plastic lining, water condenses on the insides of the hive; and runs out through drainage holes at the bottom." He says they use what is
called a 'cold' or 'closed' system, as opposed to the 'hot' or 'open' system
of the normal top bar hive. "By this we mean that the entrance faces
directly onto the first frame, which is a barrier to air entering the hive.
A normal top bar hive has the entrances at the side of the box, which means
that air can enter between the frames and circulate too freely through the
hive, and can result in undue cooling in the brood area. We are adamant that
maintenance of brood chamber conditions is of primary importance. If you can
get the queen to lay as many eggs as possible, and prevent unwanted pseudo
queens in the hive you will have a better swarm, better field workers and
a better honey crop." There has been a keen interest in the hive from overseas beekeepers. in 1998 Crispin went to Apimondia, a meeting of International beekeepers in Belgium, and to the International Federation of Beekeepers in England. Another possible application is that disabled people can now consider beekeeping because the hives can be set at a convenient height, or mounted on a mechanism for raising and lowering them. A man in wheelchair in Belgium told him that the important thing is to have a system where you don't need a lot of energy to harvest honey. In conclusion, he says, they are now convinced that a horizontally aligned bee hive of sufficient size to accommodate a vigorous queen, and with enough storage combs for a strong nectar flow, is the correct design for commercial bee keeping in tropical regions. Our hive is not intended to replace other forms of hives but to fit into its own specific niche within the field of beekeeping. We are continually modifying our hive to best serve the needs of apiculture in our tropical climates. |