On-farm evaluation of bee space of langstroth beehive

Abu Teffera and G/Selassie Sahile*

Post-harvest technology researcher, Bahir Dar Agricultural Mechanization and Food Science Research Center,
P.O. Box: 133, Bahir Dar, Ethiopia
* Post-harvest technology technical assistant, Bahir Dar Agricultural Mechanization and Food Science Research Center,
P.O. Box: 133, Bahir Dar, Ethiopia
abuteffera@yahoo.com

Abstract

The study was conducted from July 2006 to December 2007 at East Gojjam and West Gojjam zone of Amhara regional state, Ethiopia. The objective of the study was to evaluate and identify appropriate bee spaces for different agro ecology on farm condition. For this study three trail sites that represent the highland and lowland agro ecology areas were selected. From each sits three beekeeping farmers were selected as host farmers to carry out the study. The treatments were three Langstroth bee hives contain different bee-space (7mm, 10mm and 14mm) replicated three times at each trail site and complete randomized design (CRD) was used. The collected data were analyzed using one-way analysis of variance.  Farmer’s comments also included for evaluation purpose.

Based on the analysis of variance and participant farmer’s comments, hives with bee spaces 7mm, and 10mm were found to be useful around lowland and highland areas. It will be most convenient to use the bee hive having 7mm bee space around lowland area and bee hive having 10mm around highland areas of the region. It is also necessary to use all management aspects so as to increase honey and honey products, since, only by maintaining bee space cannot bring good return. 

Keyword: Bee, beehive, bee-space

Introduction

Beekeeping is a useful sideline activity to most Ethiopian farmers. They use fixed comb beehives, which are traditionally made from locally available materials. Estimates show that there are more than 0.6 million beehives and the annual estimated honey production is 334 tones in the region in which nearly 99% of them are traditional hives (CSA 2001/02).  So that beekeepers are interested in obtaining the greatest possible yield of good quality honey at the lowest possible investment in labor and capital. But, the simplest, cheapest hive, operated on a simple honey gathering basis, dose not usually permit the farmers to obtain large quantity of honey.  The product they does obtain mixed with wax, broad and other impurities and often insufficiently ripe, can only exceptionally meet urban commercial standards. But using modern movable frame hives makes them possible to obtain combs of honey, unmixed with broad, that can fully separated from its wax by centrifuging if desired. The modern bee hives has advantage of making easy inspection of the interior of the hive, thus making better bee management possible. Therefore, to get more honey with good quality, it is required same investments and attention to management of beekeeping activities. 

So, it is necessary for the farmer to use the movable frame hives in order to be benefited the advantage of the hive there by make better quality and quantity of honey production. Langstroth frame hive is the most popular and extensively used hive in America, Europe, Asia, Australia, and Northern and Southern Africa. But, frame hives imported from these parts of the world cannot be successfully used in tropical Africa because honeybees found in temperate and sub-tropical regions are larger in size than the African bee and therefore require a larger bee space, and this leads to a different set of frame dimensions (Stephen 1990).   

Therefore, the most important aspect of the hives dimensions is the space left for the bees. The "Bee Space" is the gap between and around frames, which the bees will tolerate without trying to enlarge or block off thereby reducing the tendency for bees to stick the frames together or tear down the comb. This bee space, which should be between 6.35 mm and 9.53 mm of an inch, is vitally important to both the bees and the beekeeper. If a smaller space is left, the bees will stick the comb together, making inspection difficult. If the space is left wider bees will try to build another piece of comb in it (Curtis 1982).  That is whey during construction of beehive, it is important to note the species and the races as important determining  factor for dimension of hive, frames, queen excluder (size of the opening) foundation sheet (cell dimension) and width of the comb spacing (natural distance of the comb). By considering the design factors, the bee space will be maintained at each end of the frame, above and below and on each side. 

Hence, it is essential to identify the size of bee space to use according to the bee races or environmental condition. So that the accessible  langstroth  beehive should be further studied on farmer’s management’s  at  different agro ecology conditions for their suitable bee space for existing bee races to produce convenient working environment for the bee activities  to harvest better honey  and able to make appropriate recommendation of bee space for different agro ecology.  So that, this study is aimed on verifying and selecting of suitable bee- space among langstroth beehive.

Materials and methods

Description of treatments (langstroth bee hives)

Langstroth hives were used for evaluation purposes. The parts of this hive are made of wood. It contained broad chamber, two supper and cover. The cover is laminated by 0.28 mm galvanized sheet metal. Each box has the same size and holds exactly equal numbers of frames. The boxes are mounted one over the other as required. The bottom box is mostly used for reproduction of bee colony and home of the queen and the rest boxes were used as honey storage. The treatments were identical by their type of material used and the function, but according to their frame sizes the value of the bee space is different. The overall sizes of a single hive box having bee spaces 7mm, 10mm and 14mm are equal to 50 x36.5 x 24.5 cm, 50 x 39 x 24.5 cm, and 50 x45 x 24.5 cm length, width and height respectively. 

Evaluation procedure  

The study was conducted from July 2006 to December 2007 at East Gojjam and West Gojjam zone of Amhara regional state, Ethiopia. For this study three trail sites that represent the highland and lowland agro ecology areas were selected. Participant farmers and sites were selected based on the criteria set and through discussion with the respective district Agriculture and Rural Development Office experts, development agents and farmers at the experimental location.  The locations of the study were Geray,from West Gojjam    that  represent the lowland  agro-ecology and from East Gojjam  at Enerata  and Dejen trail site  that represents the  highland agro ecology. For each trail sites three participant’s farmers were selected. Practical training was providing to the host farmers on operation and management of bee hives in order to minimize the factors that influence the result of the experiment. All participants were volunteered to participate in the study and have experience on beekeeping activities. 

Three different sizes of langstroth bee hive having 7mm, 10mm and 14mm bee space were used as treatments for the study.  Their  manufacturing drawing were  prepared  and  a total of 27 beehives nine from each size were manufactured at Bahar Dar Agricultural Mechanization and food science Research center work shop. The treatments were replicated three times at each trail site and complete randomized design (CRD) was used.

Follow up was under taken two times a year that is on dearth and harvesting time. During these times, bee colony transferring time, absconding, colony strength, number of honey comb frames harvested, attached frames together and additional comb build to the normal frames were observed and recorded on the data sheet. The amount of pure honey that identified per frame bases from each treatment was measured before and after extracting using spring balance having 0.01kg precision.  Finally outputs of pure honey per frame and formers preference among the three treatments were used for comparison purpose. The collected data were analyzed using one-way analysis of variance.  Data from Dejen trail site was not included for evaluation purpose, due to inadequate data collected and can be substituted by the data collected from high land trail sites. 

Results and discussion

The discussion was based on the results collected from Enerata and Geray trail sites. These two sits were representing for highland and lowland agro-ecologies respectively. It was aimed to investigate the most effective size of hive bee-spaces at the two extreme agro-ecological locations.   

In each experimental site 24 honey comb frames were assigned randomly to the three treatments, randomly eight frames to each of three treatments. The outcome of the experiment has been given in table 1a below with total and means of the treatments. Analysis of variance result also shown in table 1b.  

· T₁ = Langstroth bee hive having frame center to center distance 32mm or 7mm bee space

· T₂ = Langstroth bee hive having frame center to center distance 35mm or 10mm bee space

· T₃ = Langstroth bee hive having frame center to center distance 39mm or 14mm bee space

By consulting F table for 2 and 21 degree of freedom, the critical value was found as 3.47 at α = 0.05 the obtained value of F = 5.9 far exceeds the critical or tabled value.  On the basis of the F test, the experiment concluded that the bee-space of the three langstroth hives studied were not equally efficient for high land topographical location (Table 1b).

Therefore the different size of hives bee-spaces produced significant difference among the treatments. However as F is an overall index, does not indicate which of thee difference among the pair of mean are significant. To find this, post hoc comparisons between treatments means is done.  The result was shown in table 1c.   

Thus approximately 28% of the variance in the dependent variable is accounted for by the difference in the usage of bee spaces that could provide for the bee colony convenient working environment. In other words, there is fairly enough relationship between bee colony (location) and the bee spaces for the results of honey yield. That is whey langstroth hive with 10mm bee space perform better than others hives at highland

 
Formula used for strength of association is:

 
The analysis of the raw data found from Geray trail site (Table 2), show that slight difference on the yield of honey per frames among the treatment. But the single factor analysis of variance show that the difference among the treatments on the rate of pure honey production per frame not significant. However even though there is no significant difference among the bee spaces, there was seen a difference of honey yield among the hives per frame, that is 1.19, 0.995 and 0.987 kg/frame respectively (Table 2).  

Inappropriate bee space reduces honey yield. Consequently, the bee space must be maintained at each end of the frame, above, below and on each side. If a smaller space is left, the bees will stick the comb together, making inspection difficult, and if wider, they will try to build another piece of comb in it which makes difficult to remove the frames without breaking the comb and thereby damaging the colony or losing a part of the honey crop.  The test shows that out of five 14mm langstroth beehives type harvested frames, three of them were observed that bees built additional piece of comb, whereas the rest were found free of additional built combs (Figure 3). This condition confirms the above facts described about the consequence of using inappropriate bee space. Therefore, the existing 14mm bee space beehive does not maintain the required bee-space for the study area.  

But the factors for high honey production are not only bee space, but the gap has also great influence on honey yield. The majority studies conducted around bee keeping area advises that frames should be 35 mm center to center for European races of the western hive bee, and 32 mm for African races. So that they recommended range of bee spaces that should be between 6.5 up to 10mm (Curtis 1982). Based on these facts, bee hives with 7mm and 10mm bee space shows good performance around lowland and highland areas. The average honey yield was 1.19 and 2.05 kg/frames respectively. The reason is these hives are found at the ranges between this generally suggested standard of bee spaces and become suitable for bee races found at highland and lowland areas.  

Photo 1. Additional attached to the main comb

In agriculture, there is increasing use of pesticides for the control of insects, and diseases of crop plants. But in other hand bee are killed by pesticide usage on crop protection and results in direct loss of honey production. Our observation found that this condition was the major problem, because Pesticides reduce the foraging areas available to the bees to utilize potential forages, kill bees, reduce colony strength and contaminate hive products. This condition strongly contributes negative effect around Dejjen trail site for the numbers of hives not to be harvested and also rejection of the data.  

The purpose of proper bee colony management and bee space selection is to support the colony to build up to its maximum capacity during the main nectar flow and to survive the dearth, because well-managed colonies reduce number of colony absconding and assure the greatest possible return for the beekeeper.

Absconding due to inappropriate bee spaces will results by influencing the proper bee colony working environment. But same studies describes that absconding is the colony's natural response to such unfavorable hive environments or attacks by the bees' enemies. (Senguttuvan  et al). On table 3 shown the numbers of bee colony absconded within two years. It also indicates that the rate of absconding is reduced from year to year, that means the knowledge of farmer increased how to handle and control absconding of bee colony.

Therefore, the results shows that the necessity of technical and hive management issues to be considered strongly. So that it is advised that the most practical and appropriate approach for minimizing the absconding behavior of colonies lies in good colony management, good hive construction including on proper selection of bee space, suitable apiary sites, supplemental feeding during dearth periods, prevention and control of honeybee pests, diseases. Further than the technical and statistical evaluation, participant farmers from all trial sites, based on their own criteria’s make their chose among the hives.

According to their opinion some of participant farmers believe that hive having less volume helps the colony to control over all frames immediately.  This condition gives them to have less to be attacked by wax moth, will be easy to maintained internal hive temperature and since it has less size simple to carry with out no difference on honey yield pre hives.  In other hand, there was also a threat that the small size hive like having 7mm bee space might restrict free movement of the colony.   The large one like hive having 14mm bee space is too wide to control by limited number of colony. So that they prefer the average one which is not very small or very big like hive having bee space 10mm. Therefore, Out of nine participant farmers from the three sites, four of them selected bee hives having 10mm bee space, two of them were selected the hive having bee space 7mm and the rest make their chose on hive having 14 mm bee space for their respective areas.  

Conclusion and recommendation

• Beehive having 14 mm bee spaces can be used as bee colony nest but has draw backs. The major problem is due to   excess space between frames and box which is not suitable for African bees that have small size.  So the bees build an additional comb that will not be easy to separate the comb without breaking. This results in less honey production as it requires much time and energy for bees to build unnecessary comb between the excess free spaces.  But for the others two bee hives, having bee space 7mm and 10mm, according to the test results, observation and farmers opinions they are found suitable for the type of honey bee races found in the study area. It will be most convenient to use the bee hive having 7 mm bee space around lowland area and bee hive having 10 mm around highland area of the region.  Maintaining the bee space alone cannot enhance honey production. This has to be harnessed with improved management practices so as to maximize good return to beekeeping farmers. Therefore it is necessary to follow strongly proper hive management techniques that will ensure greater honey crops. 

References

Received 24 June 2011; Accepted 14 July 2011; Published 10 October 2011

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