Masterarbeit, 2018
100 Seiten
ACKNOWLEDGMENTS
ABBREVIATIONS
TABLE OF CONTENTS
LISTS OF FIGURES
LIST OF APPENDIX TABLES
LISTS OF APPENDIX FIGURES
ABSTRACT
Chapter 1. INTRODUCTION
1.1 Background and Justification
1.2. Statement of the problem
1.3. Objectives
1.3.1. General objective
1.3.2. Specific Objective
Chapter 2. LITERATURE REVIEW
2.1. Evolution of Bees and Beekeeping
2.2. Races and Species of Honeybees
2.3. Important Races of Honeybees
2.4. Geographical Distribution of Ethiopian Honeybees
2.5. Overview of Beekeeping System in Ethiopia
2.5.1. Traditional Beekeeping
2.5.2. Transitional Beekeeping
2.5.3. Modern and Frame box beekeeping
2.6 Opportunity of Bee Keeping In Ethiopia
2.7. Major constraints for Beekeeping in Ethiopia
2.7.1. Lack of skilled manpower and training institutions
2.7.2. Marketing problems
2.7.3. Inadequate of rural credit service
2.7.4. Agrochemicals Application
2.7.5. Major Honeybee pests
2.8. Honeybee Disease
2.8.1. American foulbrood (AFB)
2.8.2 European foulbrood (EFB)
2.8.3 Chalk Brood (CBD )
2.8.4 Stone Brood (SBD)
2.8.5 Amoeba Disease
2.8.6 Nosema Disease
2.9. Parasitic mite
2.10. Honey Bee Disease and pest Status in Ethiopia
Chapter 3. MATERIALS AND METHODS
3.1 Description of the Study Area
3.2. Data sources and methods of collection
3.3. Types of data collected
3.4. Sampling technique and sample size determination
3.4.1. Honeybee and Brood sampling
3.4.2. Field Observation
3.5. Laboratory Examination Procedures
3.5.1. Laboratory Examination of Varroa destructor
3.5.2. Laboratory examination of tracheal mite
3.5.3. Laboratory examination of Nosema and Amoeba diseases
3.5.4. Laboratory examination of chalk brood disease
3.5.5. Examination of American Foulbrood and European Foulbrood using
3.6. Data management and statistical analysis
Chapter 4. RESULT AND DISCUSSION
4.1. Socio-demographic characteristics of the respondent
4.2. Beekeeping Practice
4.2.1. Vegetation type and land holding of beekeepers
4.2.2. Land holding and land use of the respondents
4.2.3 .Bee forage farming practice
4.2.5. Beekeeping activities and potentials
4.2.6. Sources of honeybee colony
4.2.7 Season of active and dearth period
4.2.8. Trends of bee hives type, colony number and honey productivity
4.2.9. Purpose of beekeeping and Placement of honey bee colony
4.2.10 .Trend of honey bee colony and products
4.2.11. Agents of increasing honey bee colony population and products
4.2.12. Cause of honeybee colony and yield decrease
4.3. Major pests and predators in Wayu Tuka and Diga
4.3.1. Types of bee hive and effects of disease
4.4. Agrochemical application and its effects on honeybees
4.4.1. The use of agrochemicals
4.4.2. Types of agrochemicals used by beekeepers
4.4.3. The effect of Agrochemical application on beekeeping
4.4.4. Local control method of agrochemicals
4.5 The prevalent and incidence rate of honeybee disease and parasitic mites
4.5.1 .Prevalent and incidence of chalk brood disease
4.5.2 .Prevalent and incidence rate of Amoeba disease
4.5.3 .Prevalent and incidence of Nosema disease
4.5.4 Prevalence and infestation of Varroa mites
4.5.5 The prevalent and Incidence of bee lice
Chapter 5 .CONCLUSION AND RECOMMENDATIONS
REFERENCES
APPENDIX
Above all I would like to thank the Almighty of GOD without Whole blessing, it would not have been possible all my wishes to come in to reality.
I am very grateful to my advisors Dr. Hailu Mazengia and Dr Amssalu Bezabih for accepting me as their advisee, for their professional supports and due concerns from the very start of designing the research proposal up to the whole work of this study.
I am also grateful to the financial assists of Oromia Agricultural Research Institute as my support for the whole study and Bahir Dar University for hosting me.
I am grateful to Bureau of the Livestock and Fishery of Diga and Wayu Tuka districts, and Holata Bee Research Center for their laboratory support and guidance. Grateful acknowledgements are extended to the districts apiculture experts and bee technicians for their co-operation and to the sample respondents in supplying relevant information in addition to their hospitality during the period of data collection.
I wish to thank staff of the Department of Animal Production and Technology of Bahir Dar University for their support and friendship during my years of study, particularly Dr Muse Hailemelekot, Dr. Asaminew Tassew, Fantahun Mehiret and Damitie Kebede. I would also like to extend my sincere thanks to Dr Desalegn Begna for his comment, Alemayehu Gela, Hiwot Habtewoldi, Gete Daba and Gete Ayele who have helped very greatly during all the laboratory work at HBRC and for their considerable supports
This is dedicated to my beloved father Ato Arega Buli, my much-loved mother Woynitu Limenih, to my brother's son Tekalign Tamene and all my lovely family members and friends. Finally, I would like to express my deepest and endless thanks to my wife Ebise Ejeta for her wonderful support and encouragement.
Abbildung in dieser Leseprobe nicht enthalten
Table 1. Socio- demographic characteristics of households
Table 2. Vegetation type of Diga and Wayu Tuka Districts
Table 3. Land holding and land use of the respondents in Diga and Wayu Tuka Districts
Table 4. Bee forage farming practice
Table 5. Beekeeping starting time in the Diga and Wayu Tuka
Table 6. Source of honeybee colonies in Diga and Wayu Tuka Districts
Table 7. Placement of honey bee colony in Diga and Wayu Tuka Districts
Table 8. Trends of honeybee colony and products in Diga and Wayu Tuka Districts
Table 9. Cause of honeybee colony and yield decrease in Diga and Wayu Tuka Districts
Table 10. Honeybee pest and predators in Diga and Wayu Tuka Districts
Table 11. Effect of honeybee disease on types of hive
Table 12. The effect of agrochemical application on beekeeping in in Diga and Wayu Tuka Districts
Table 13. Local control method of agrochemicals in Diga and Wayu Tuka Districts
Table 14. Prevalent and incidence of Chalk brood disease
Table 15. The Prevalent and incidence rate of Malpighamoeba mellificae
Table 16. prevalent and Incidence rate of Nosema apis in inspected apiaries and honeybee colonies. . 56 Table 17 The Prevalent of varroa destructor
Table 18. Incidence rate of Varroa destructor
Table 19. Prevalent of bee lice in inspected apiary sites
Table 20. Incidence rate of bee lice
Figure 1. Small hive beetle adult and larvae
Figure 2. Wax moth larvae and adult
Figure 3. Nosema apis infecting the abdomen of bee
Figure 4. World distribution of varroa destructor
Figure 5. Life cycle of varroa destructor
Figure 6. Honeybee trachea infected by Acarapis woodi, Approx. 150 pm in length
Figure 7. World distribution of Acarapis woodi
Figure 8 Map showing the location of the study area
Figure 9 Flow chart of sampling strata of Diga and Wayu Tuka districts
Figure 10 Field examination and laboratory diagnosis procedure and results
Figure 11 Factors affecting bee forage planting in the Diga and Wayu Tuka
Figure 12. Season of active and dearth periods in Diga and Wayu Tuka Districts
Figure 13. Trends of honeybee hive type, colony number and honey productivity
Figure 14. Cause of increasing honey bee colony population and products
Figure 15 Major pests and predators in Diga and Wayu Tuka Districts
Figure 16. Agrochemical application in in Diga and Wayu Tuka Districts
Figure 17. Types of Agrochemicals in Diga and Wayu Tuka Districts
Figure 18. Laboratory result of Ascosphaera spore
Figure 19. Laboratory examination of Nosema apis and Malpighamoeba mellificae
Figure 20. Laboratory examination of brood for Varroa
Appendix Table 1 Local control practices of honeybee pests and predators
Appendix Table 2 Type of sample for laboratory diagnosis of disease
Appendix Table 3 Questionnaire for Beekeepers
Appendix figure 1 Honeybee diseases and pest Laboratory and field examination
The Prevalent and Incidence Rate of Honey Bee Diseases and Pests in Selected Districts of East Wollega Zone, Oromia National Regional State, Ethiopia.
The study was conducted in East Wollega Zone, Oromia Regional State, Ethiopia, from December, 2016 up to August, 2017 to determine the prevalent and incidence rate of honeybee disease and pests. Questionnaire survey and laboratory diagnostic methods were used for the study. The questionnaire was administered to 146 beekeepers (97.1% males) and two honeybee colony samples from each beekeeper totally (292 honeybee colonies) were collected from transitional and frame box hives for laboratory diagnosis. The honeybee samples collected were examined in laboratory for the prevalent and incidence rate of honeybee disease pathogens and pests. Majority of the respondents started beekeeping after 2010 (28.03%) by catching colonies as honey bee colony source (54.8%). The major dearth period of the area was late march to early may. The trend of beekeeping in the study area was shifting from traditional to modern beekeeping and the trend of honeybee colony and its yield was decreasing due to honeybee health problem of the area (pests, predators, pathogenic disease, high cost of bee equipment and agrochemical application). In the study area the major pests and predators considered as challenges were ants, beetles, wax moth, varroa destructor and some predators like honey badgers, bee eater birds, dead head hawks moth, lizards, wasps and birds respectively. Varroa, Nosema, Amoeba and chalk brood disease were confirmed while tracheal mite, stone brood, Ameriacan and Europian foul brood did not confirmed during the study period. The prevalent and incidence of varroa destructor was higher in dry season than wet season while the prevalent/incidence rate of nosema and chalk brood disease was limited during dry season. Amoeba disease was distributed in both seasons. For the reason of time restraint in this study area, farther study on economic threshold of honeybee disease and pests is suggested by monitoring throughout the year.
Key words : Disease, Honeybees, Infestation, Oromia, Pests, Prevalence,
Beekeeping is a long-standing practice in the rural communities of Ethiopia (Gidey Yirga and Mekonen Teferi, 2010) and the beekeeping sub-sector has been an integral part of agriculture in Ethiopia. It has been contributing to the household income and poverty alleviation and national economy through export. The country has huge apicultural resources that made it the leading honey and beeswax producer in Africa (Gemechis Legesse, 2014). Ethiopia is known for its tremendous variation of agro-climatic conditions and biodiversity which favored the existence of diversified honeybee flora and huge number of honeybee colonies (Nuru Adgaba, 2007).
The country is also one of the four largest beeswax producing countries and this commodity is one of the major exportable products and in 2010/2011, about 620,101 kg of honey was exported (CSA, 2011) and annually an average of 420 million Ethiopian Birr is obtained from the sale of honey (Gidey Yirga and Mekonen Teferi, 2010). The total number or population of honeybee colonies of the country is estimated to be about 10 million, of which about 7.5 million are tamed and the remaining exist as feral colonies in the forest (SNV, 2005).
Like all other insects, honeybees (Apis mellifera) are susceptible to pests and diseases, the majority of which are specific to honey bees. It is important for beekeepers to be aware of these disorders, learn to identify them and effectively manage disorders to maintain healthy colonies. This is particularly important because the health of one beekeeper's colony can impact another beekeeper's colony in the surrounding area (FOA, 2006).
The honey population and its products decline from time to time by some factors like, honey bee disease, pests, predators, pesticide, environmental stress and genetic disorder (IIS, 2013). Some of pests and diseases are quite common while others are rarely encountered. It is important for beekeepers to be aware, learn to identify them and effectively manage pests and diseases to maintain healthy colonies. This is particularly important because the health of one beekeeper's colony can impact another beekeeper's colony in the surrounding area (Paul, 2016).
The economic loss associated with the presence of honey bee diseases and pest was estimated in some works and significant loss was reported. In the present time the major honeybee diseases, pests and predators and their rate of distribution was reported in Ethiopia (Haylegebriel Tesfay, 2014).
The current problem of beekeepers is there is a shortage method for efficient assessment of honeybee health. This makes it difficult to know the severity of losses with any meaningful degree of certainty. This will require increased cooperation by members of the industry with government survey groups such as the National Agricultural Statistics Service (NASS). In addition, growers should be included honeybee colony health in any survey (USDA, 2012).
There should be regular and wide scale diagnostic survey that monitor the occurrences of new one and also that establishes the distributions of the already reported for constraining measures. There are still insufficient evidences on the side effects of pests and diseases. Very importantly, comprehensive strategic response to the recently occurred varroa mite threat in determining its thresholds, economic damages and behavioral attributes with devising control options are very important (Desalegn Begna, 2015).
There are many honey bee diseases (bacterial, fungal, viral, microsporidial), parasites (mites), predators (bears, birds, humans), and pests (beetles, moths) that can adversely affect managed honey bee productivity and survival (Morse and Flottum, 1997). Colony strength and health status are regularly assessed, and samples are taken and checked for disease and parasite loads. Although laborious and cost-intensive, this project has proven useful, because it generates reliable data enabling relationships between risk factors and colony death to be determined (Dennis and Marina, 2010).
Like other living organisms, the life and products of honeybees are affected with harmful diseases, pests and toxic materials. Successful beekeeping requires regular and on time monitoring of any factors that endangers honeybee life and threaten their products. Apart from identifying the occurrences and distributions of endangering factors, regular monitoring helps to think on devising prevention and/or control mechanisms. To these facts, series of field diagnostic surveys and laboratory analysis works has been conducted to identify and characterize honeybee diseases and pests associated with local honeybee of Ethiopia (Desalegn Begna2015).
The adequate methods for defining and assessing the causes of death of honey bee colonies are not well implemented. This makes it difficult to assign annual die-offs to specific causes, and that makes it difficult for beekeepers to know what problems should be demanding their greatest attention. A well-defined list of symptoms for each honey bee pest, parasite, pathogen and predator allows for differential diagnosis of honey bee pathologies. Due to this difficulty in diagnosing a problem, it will be necessary to collect and archive samples of bees for regular basis. Accordingly, in East Wollega Zone there is no research information on honeybee disease and pests with prevalent and incidence rate in the area. Therefore, this study was conducted to assess the prevalent and incidence rate of honeybee disease and pests in the area.
To magnify honeybee pests and diseases by diagnostic survey and determine the prevalent and incidence rate of honey bee diseases and pests in selected districts of East Wollega Zone.
- To identify the common infectious disease and pest.
- To determine the prevalent of honeybee disease and pests.
- To determine the incidence rate of honeybee disease and pests.
1. What are major factors affecting honeybee health?
2. What are the common honeybee pests and disease in the area?
3. What is/are the prevalent and the incidence rate of honeybee disease and pests in the area?
According to the common gene pool of the main subfamilies of apidae is “Electrapis” of the Eocene, a rather vague group comprised of individuals with a varying mosaic of meliponoid, bomboid and apinoid characters. The subfamilies evolved in different directions and radiated during different epochs as shown by the rank of taxonomic units: Meliponinae 18 genera (300 species), Bombini 3 genera (290 species), Apinae 1 genus (4 species) (Friedrich, 1987).
The first global analysis of genome variation in honeybees has been revealed by scientists. The findings show a surprisingly high level of genetic diversity in honeybees, and indicate that the species most probably originates from Asia, and not from Africa as previously thought. The honeybee (Apis mellifera) is of crucial importance for humanity. One third of our food is dependent on the pollination of fruits, nuts and vegetables by bees and other insects. Extensive losses of honeybee colonies in recent years are a major cause for concern (Uppsala 2014).
Race in honeybees is a result of natural selection and honeybees have been adapted to different geographical areas of the world for many years without the interference of mankind. In so doing, there has been an environmental effect on the anatomy and physiology of honeybees leading to differentiation (Roubik, 1989).
Honeybees (Apis mellifera) consist of Most of these subspecies have been classified according to their morphological characteristics more than 24 different subspecies exists, and morphological characteristics thus have an important role in the classification aspects of honey bees. Different sets of wing and body morphological characteristics have been used to characterize and classify the subspecies by many authors and for various reasons. Wing venation characteristics have been studied more intensely than other body morphological characteristics (Hossam et al, 2013)
African and European honeybees, even though were from the same species, are differing in behavior, production and on some morphological variables of importance. Hence, quite a large number of subspecies (races) of honeybees are found in the world today. The presence of 23 distinct geographical races using multivariate analysis of the morphometric characteristics of honeybees was reported. In Africa alone, more than 16 subspecies or races are residing in different ecological places (Ruttner, 1986).
The races of Apis mellifera L. have evolved as a result of long periods of geographical isolation and ecological adaptation (Nuru Adgaba, 2002). The races and strains of Apis mellifera are overriding world importance in beekeeping, and are the basis of world's beekeeping industry. These bees are native to Africa and Europe. They have also been introduced in to almost the whole of the New World (the Americans, Australia, New Zealand and Pacific Islands) since 1500 where there were no native honeybees (Crane, 1976). European Apis mellifera is the bee first studied, and it still receives by far the most attention.
The races of Apis mellifera, especially honeybee is well distributed over the globe except in the severe cold of the Polar Regions (Adjare, 1990). It has, however, been shown that bees can also be kept in the desert or in urban areas (Vivian, 1985). They are generally less amenable to handling and management, swarm readily; also, the whole colony may abscond as a result of damage and disturbance of their nest or shortage of food. Moreover, the bees are easily alerted to sting and this allows their survival in the African tropics where they were liable to be attacked by many ‘enemies' (Crane, 1990).
According to recent study done on morph clusters of geographical races of Ethiopian honeybees five honeybee races have been reported to exist in the country. A.m. monticola exist in the northern high mountainous part of the country, A. m. bandasii found in central highlands of the country, A. m. scutellata f ound in the wet tropical forest lands, A. m. jemenitica is the yellowest honeybee but also consists black members and A.m. woyi- Gambella found in the extreme western and southern semi-aired to sub moist low lands found only in Ethiopia (Amssalu Bezabih , 2002).
As far as morphometric analyses of Ethiopian honeybees reported that Apis mellifera monticola from the Ethiopian plateaus (Smith, 1961) and later the presence of A.m. scutellata and A.m. jemenitica reported (Ruttner, 1975). Also (Ayalew kassaye, 1990) reported the existence of five honeybee races: Apis mellifera jemenitica (in eastern lowlands), A.m. monticola (in the southern mountains), A.m. litorea (in the extreme western low lands), A.m. adansonii (in the southern mid-altitude areas) and A.m. abyssinica (central plateau and southwestern parts of tropical forest) and (Radloff and Hepburn, 1997) recorded A.m. jemenitica, A.m. bandasii and A.m. sudanensis from Ethiopia.
However, these findings are inconsistent except for A.m. monticola and A.m. jemenitica and none of the results indicated the distribution, behavior and biology of these honeybees for the whole of Ethiopia. The smallest and yellow honeybee, A.m. woyi-gamballa in the western and southern lowlands; the small and yellowest honeybees, A.m. jemenitica in the eastern escarpment; relatively large and dark honeybees, A.m. bandasii in the central and eastern highlands; and dark honeybees, A m. scutellata in the wet tropical forests (Amssalu Bezabih, 2002).
The results of the northern and southern regions were well fitted to each other and multivariate morphometric analysis of the merged data (northern and southern) revealed the existence of five statistically separable morph clusters occupying ecologically different areas: Apis mellifera jemenitic a in the northwest and eastern arid and semi-arid lowlands; A.m. scutellata in the west, south and southwest humid midlands; A.m. bandasii in the central moist highlands; A.m. monticola from the northern mountainous highlands; and A.m. woyi-gambella in south western semi-arid to sub-humid lowland parts of the country (Amssalu Bezabih et. al., 2004).
In Ethiopia, apiculture has been practiced for centuries around the country and its potential is well documented. The beekeeping systems in Ethiopia are classified into four major systems: honey hunting, Traditional, top-bar and movable-frame hives. Honey hunting from habitats like tree cavities, Caves or other natural opening is a feral system of harvesting honey by destroying the whole Colonies and this type of honey harvesting common in few remote west and southwest parts of the country among traditional communities (Nuru Adgaba, 2007).
Ethiopia is blessed with adequate water resources and various honeybee floras, which create fertile ground for the development of beekeeping. Honey hunting and beekeeping have been practiced in the country for the exploitation of honey. In places where wild colonies of bees living in hollow trees and caves are found, honey hunting is still a common practice in Ethiopia (Tessega Belie, 2009). According to (Ayalew Kassaye, 2008), currently in Ethiopia beekeeping is practiced in three types of production systems namely; traditional, transitional and frame beehive beekeeping.
Traditional beekeeping is the oldest and the richest practice, which has been carried out by the people for thousands of years in Ethiopia. Ethiopia has huge potential for honey production which is clearly observed in the last few years with significant increment, even though the subsector is still practicing with traditional low productive systems. Research and extension made so far have tried to improve this scenario in the country. Various investigations in particular have identified the problems in the production and marketing of the Ethiopian honey industry (Gemechis Legesse, 2014).
This beekeeping practice is extensive and closely tied to swarm management: beehives are hung up in trees to catch swarms and are then transferred to the ground. Often, such beehives are placed in a kind of bee house that protects the beehives from the heat and rain. Several million bee colonies are managed with the same old traditional beekeeping methods in almost all parts of the country (Fichtl and Admasu Addi, 1994). Thus, two types of traditional beekeeping are found in the country: forest beekeeping by hanging a number of traditional beehives on trees and backyard beekeeping with relatively better management (Nuru Adgaba, 2002).
This type of beekeeping is one of improved methods of beekeeping practices that can be constructed from timber, mud or locally available materials. Each hive carries 27-30 top bars on which honeybees attach their combs. The top bars have 3.2cm and 48.3cm width and length, respectively. Transitional (intermediate) beekeeping practice has different advantages such as, it can be opened easily and quickly, the bees are guided into building parallel combs by following the line of the top bars, the top bars are easily removable and this enables beekeepers to work fast, the top bars are easier to construct than frames, honeycombs can be removed from the hive for harvesting without disturbing combs containing broods, the hive 7 can be suspended with wires or ropes and this gives protection against pests (HBRC, 2004).
Transitional beekeeping is an intermediate beekeeping system between traditional and frame hive beekeeping practices. Generally, top-bar (Ethio-ribrab) beehive is a single or double story long box with slopping side walls inward the bottom and covered with bars of fixed width; 32 mm for east African honey bees (Sisay Gobessa et. al., 2012). The advantages of top-bar hives include: Each comb can be accessed independently without disturbing the others. This ensures that bees are able to build combs right below each top-bar (Lukas, 2011).
Transitional beekeeping has its own disadvantages such as, top bar beehives are relatively more expensive than traditional beehives, and combs suspended from the top bars are more apt to break off than combs which are building within frames (HBRC, 2004). According to HBRC, transitional beekeeping started in Ethiopia since 1976 and the types of beehives used are: Kenya top-bar beehive, Tanzania top-bar beehive and Mud- block beehives. Among these, KTB is widely known and commonly used in many parts of the country (HBRC, 1997). The top bars are easier to construct than frames, honeycombs can be removed from the beehive for harvesting without disturbing combs containing broods, the beehive can be suspended with wires or ropes and this gives protection against pests. However, as compared to traditional beehives relatively it is expensive in price.
Modern beekeeping includes methods of honey, introductory, life of the honeybee, species of beekeeping, site selection and arrangement of apiary, beehive, food gathering by bees, management of bee colonies, management and diseases pest, extraction of honey & processing, quality of honey, equipment, economics of beekeeping. In the frame box hive beekeeping the frames are so arranged that they can be removed individually without disturbing other combs and without crushing bees, and the sides and bottom of the frame provide very good support for the comb (Adjare, 1990).
The frame hive beekeeping methods aim to obtain the maximum honey crop, without harming bees. It uses different types of frame beehives. Zander, Langstroth, Dadant, Modified Zandar, and foam beehives were existed in the country (Ayalew kassaye, 2001).
Langstroth also found that several communicating hive boxes can be stacked one above another, and that the queen can be confined to the lowest, or brood, chamber, by means of a queen excluder. In this way, the upper chambers (called supers) can be reached only by the workers, and therefore contain only honey-comb. This made hive inspection and many other management practices possible, and turned the art of beekeeping into a full-scale industry. Almost all commercial hives in use today operate on the Langstroth pattern, although they may contain from 10 to 13 frames (Adjare, 1990).
Currently the government is highly supporting self-contained watershed developing program in which beekeeping is part and parcel. Low cost modern hives is being produced using locally available materials and efforts are being made to organize farmers in groups and link them with local carpenters who produce modern bee hive. There is an increasing demand for honey for domestic consumption and export by different customers and organizations. Though scarce in dry seasons, there are many bee forage species throughout the year in most part of the study area. Availability of rich culture and tradition of beekeeping, suitable environment with different agro ecology, availability of farmers having indigenous knowledge, skills and keen interest to adopt improved technologies and to undertake beekeeping as a way of life are among the few to mention (Biressaw Serda et. al., 2015).
Opportunities for beekeeping in the country are the presence of natural resource and human capital, the current attention of the government toward the introduction of different beekeeping technology packages, the establishment of beekeeping association and the presence of government by giving courses of apiculture as science like Bahir Dar University and non-government organization who are involved in beekeeping activities and the presence of microfinance institution at grass root level. Still the country has potential with enormous nectar and pollen source that have not yet be exploited and beekeeping could probably be profitable activity to undertake.
Constraints in the beekeeping development of the country are complex and to a large extent vary between agro-ecological zones and production systems. Variations of production constraints also extend in socio-economic conditions, cultural practices, climate (seasons of the year) and behaviors of the bees (Adjare 1990). Technical constraints in beekeeping activities include poor extension systems (absence of coordination between research, extension and farmers), lack of skilled man power and training institution, marketing problem, honeybee health problem, lack of adequate credit services, and lack of records and up-to- date information, shortage of reading materials regarding to beekeeping, and inadequate research centers to address the problems related to apiculture.
Beekeeping is one of the disciplines which suffered and is being suffering from the lack of skilled manpower, appropriately skilled trainers, training materials and training institutions in the region. Majority of the beekeepers lack the knowledge of appropriate methods of beekeeping. In the country there is no concerned college or university which can provide diploma or certificate level course in beekeeping. Holata Bee Research Center is the only center that provides basic trainings to farmers, technicians, experts and Bahirdar University is the only university gives as Apiculture program in master's degree in Ethiopia. However, this doesn't meet the ever increasing demand of trained manpower in the country.
It has been observed that in the region the marketing system of honey has many problems. Most of the local markets are far away from the beekeepers and are inaccessible. Beekeepers travel on foot for several hours to sell their honey. The lack of grading systems does not encourage farmers to produce high quality products, thus, the price of honey changes widely based on the good will of buyers. Because of beekeepers have limited knowledge of the preferences of their target market, they do not try to make any changes in the quality of their product. Presentation of quality honey is generally poor. Most honey come to market is unextracted, unstrained and poorly managed.
The improved hives and working tools to the rural community are beyond the pockets of farmers and not easily available. There is limitation of the credit services for landless youths as well as households. Even if the rural credit service is around they do not easily serve due to limitation of awareness creation (Kerealem Ejigu et al., 2009).
Pesticides are substances used to eliminate unwanted pests. Insecticides rid us of unwanted insects. Unfortunately, honey bees are insects and are greatly affected by insecticides. There are several ways honey bees can be killed by insecticides. One is direct contact of the insecticide on the bee while it is foraging in the field. The bee immediately dies and does not return to the hive. In this case the queen, brood and nurse bees are not contaminated and the colony survives. The second more deadly way is when the bee comes in contact with an insecticide and transports it back to the colony, either as contaminated pollen or nectar or on its body (UGA, 2017).
Most herbicides are not toxic to bees; destroy many plants that are valuable to bees as source of pollen and nectar. The types of chemicals used include Malathione, Sevin, DDT, 2-4 D and Acetone. As it was seen from the beekeeper point of view, poisoning of honeybees by agrochemical has been increased from time to time. Some beekeepers lost totally their colonies due to agrochemical (Kerealem Ejigu et al., 2009, Desalegn Begna 2014) recently reported that there is a growing pesticides grievance on honeybee population and their products decline with considerable economic impacts on beekeepers.
The use of insecticides continues to be a basic tool in pest management, since there are many pest situations for which there are no known alternative management methods. Poisoning of bee pollinators is a serious adverse effect of insecticide use which leads to a decrease in insect population, to reduction of honey yields, to destruction of plant communities, to insecticide residues in food, and to a significant loss of beekeepers' income (Stefanidou et. al, 2003).
Honeybees are attacked by various pests, predators and other enemies. The major bee enemies are wax moths, wasps, birds, ants, hive beetles, mites, mice and bear, which destroy the raised combs, hives and hive parts, catch and kill bees, colony development, eat away the food reserves and cause nuisance to the bees, resulting into reduced colony productivity and returns per colony. Thus, regular monitoring and surveillance of colonies for early detection of diseases and enemies and use of non-chemical methods to keep pest population densities below economic injury level should be adopted for the management of bee diseases and enemies (Yadav et.al., 2017).
Ethiopia, as one of the sub-tropical countries, the land is not only favorable to bees, but also for different kinds of honeybee pest and predators that are interacting with the life of honeybees (Desalegn Begna, 2001). The existence of pests and predators are nuisances to the honeybees and beekeepers. Pests and predators cause devastating damage on honeybee colonies with in short period of time and even overnight. According to (Kerealem Ejigu et al., 2009) ants, honey badger, bee-eater birds, wax moth, spider and beetles were the most harmful pests and predators in order of decreasing importance. Some studies indicate that Ethiopia appears to be free from various honeybee brood diseases and at the same time at low level of adult bees' diseases incidences. A major category of diseases which cause economic loss comprises amoeba, nosema and chalk brood.
Honeybees are critical to the success of the agricultural industry within the United States. The insects are credited for up to 80 percent of all insect pollination, a crucial element of fruit and vegetable production. With the exception of Africanized honeybees, the insects are not aggressive by nature; they sting only when provoked or to protect their hives. The animal world presents many predators including arachnids, insects and mammals (Lalaena, 2017).
Honeybee harmful pest and predators listed out by (Guesh Godifey 2015) were Ants, Wax moth, Bee-eater birds, Honey badger, Spiders, parasitic mites, and Dead hawks moth in order of decreasing importance (Table 6). Major honeybee pests are listed as follows;
A) Small Hive Beetle
Small hive beetle (SHB) originally, this beetle (Aethina tumida), was only found in Africa, south of the Sahara. It first appeared in the southern United States of America in 1998 and has continued to spread north as far as Canada. In Africa, the beetle’s original range, only weak colonies or storage combs are affected. On the other hand, the beetle also invades a colony during management activities, e.g. during honey extraction. There is a risk that the beetle may spread to Asia. Cause the beetle Aethina tumida (order: Coleoptera, family: Nitidididae') is called the small hive beetle (FAO, 2006).
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Adult small hive beetles are often observed in the hive with their head and antennae tucked down beneath the thorax. They are oblong in shape, around 6 mm long, with variable coloration that ranges from tan to reddish-brown, dark brown or black.
Figure 1. Small hive bee^'e adult and larvae
Source: Adapted from (Ellis, 2009)
The period of development from egg to adult beetle is at least four to five weeks and also be living in the bee colony because their legs are longer and they have a row of spines on their back and do not spin nets or cocoons. A minor infestation is difficult to recognize because the beetles immediately hide in the dark. The most secure diagnosis is achieved after chemical treatment when the dead beetles can be gathered from the bottom inlay (OIE, 2004). The small hive beetle Aethina tumida (SHB) is an invasive pest of bee hives, originally from subSaharan Africa and also reported in Ethiopia (Guesh Godifey 2015).
B) Ants
Various types of ants, from tiny sized pharaoh ants to the large black carpenter ants, can be bee pests. Relatively few ants steal honey or bee brood. The real problem is the ants' nesting inside the warm dry hive and bothering the beekeeper in colony examination (MAAREC, 2006). Ants are among the most common predators of honey bees in tropical and subtropical Asia. They are highly social insects and will attack the hives en masse, taking virtually everything in them: dead or alive adult bees, the brood and honey. In addition to this destruction, they can also be a nuisance to beekeepers and may sometimes cause pain from their bites.
Ants are most troublesome to honeybees and beekeeping sector. Among the enemies of honeybees registered in Ethiopia, Ants share the greatest grievances in causing serious problems on honeybee colonies. It kills bees, robs their products and forces the honeybee colonies to leave their proper nest which results in reduction of honey production. In Ethiopia ants in colony of 8 honeybees were reported from different regions such as Addis Ababa (Desalegn Begna and Yosef Kebede, 2005), and cause a major problem in the adoption of improved beekeeping technologies.
C) Wax Moths
Wax moth larvae are very destructive and can quickly destroy stored beeswax combs. They tunnel and chew through combs, particularly combs that have contained brood and pollen. Wax moths are two species Greater wax moth (Galleria mellonella) and lesser wax moth (Achroia grisella). Female moths usually lay 300 to 600 eggs in clusters on comb or in small cracks in hive material. The almost spherical, pinkish to white eggs are about 0.5 mm in diameter. Lesser wax moth (Achroia griselld) is smaller than the greater wax moth and has a silver-grey to dull-yellow, slender body about 13 mm in length. They feed on combs, pollen and litter found on the hive floor. They are usually solitary, whereas greater wax moth larvae often congregate in large numbers (Russell 2009).
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Figure 2. Wax moth larvae and adult
Source: Adapted from (Russell 2009).
Distr ibution of Wax moth The wax moths are one of the most important pests of honeybee colony with worldwide distributions and it was identified as one of the serious local honeybee pests (Desalegn Begna, 2001). The wax moths (smaller and larger) in honeybee colonies were reported in the South and South West parts of Ethiopia in the year 2000. Understanding the severe problems due to wax moth, research program that aimed at assessing its prevalence and special effects on honeybees and then' products has been conducted in selected three zones of the country (Amsalu Bezabih and Desalegn Begna, 2007).
The greater wax moth (Galleria mellonella') The greater wax moth is often reported to cause damage both to honey bee colonies and to bee products The main reason for very serious infestation of beeswax in the region has been explained to be due to lack of proper seasonal colony management. It is in line with (Adjare, 1990), which states, in the absence of appropriate seasonal honeybee colony management, wax moth becomes a more serious pest of honeybee colonies in the tropical Africa in general.
Ethiopia, as one of the sub-tropical countries, the land is not only favorable to bees, but also for different kinds of honeybee pest and predators that are interacting with the life of honeybees (Desalegn Begna, 2001). The existence of pests and predators are nuisances to the honeybees and beekeepers. Pests and predators cause devastating damage on honeybee colonies with in short period of time and even overnight.
American foulbrood (AFB) is the most devastating honeybee disease. It is caused by the spore-forming, Gram-positive rod-shaped bacterium Paenibacillus larvae (Dirk et.al, 2012). A Paenibacillus larva, the causative organism, is a bacterium that can produce over one billion spores in each infected larvae. AFB spread from infected colony to non-infected colony through human activity (interchanging brood, feeding pollen and honey from unknown source, extracted honey suppers), and other contaminated bee equipment), between bees (robbing, drifting, swarming) and honey pest and predators.
Europian foulbrood (EFB) disease is a severe bacterial disease of honeybee brood caused by non-spore forming Gram-positive bacterium Melissococcus plutonius. The disease is widely distributed worldwide, and is an increasing problem in some areas (FERA, 2013). EFB affects larvae of the three honeybee castes, workers, drones and queens. The disease is not observed in the pupae and adult bees. Compared to the American foulbrood, the course of the disease is less severe (Otten, 2003) but due to its wide prevalence, it causes considerable economic losses to apiculture.
Infected larvae usually die prior to cell capping due to starvation rather than invasion of the body tissues by the bacterium and in some cases larvae may die after capping or in some cases survive to pupation, producing undersized adults. Secondary invaders such as Paenibacillus alvei, Enterococcus faecalis, Brevibacillus laterosporus and Lactobacillus eurydice may multiply and are commonly found in association with EFB (FERA, 2013). EFB is not a major cause of direct colony death and infections may occur at times of stress (Genersch, 2010).
Generally the two major diseases; European Foulbrood and American Foulbrood that are common in Europe and America have not been located or recorded anywhere in East Africa. In the 2014 survey of hives, in East Africa, scientists did not detect any signs of the disease but some spores have been detected in some hives (Theorganicfarmer, 2015).
The CBD is caused by fungus Ascosphaera apis and kills larvae after capping and makes them appear white, fluffy and swollen at first before shrinking and becoming hard. By this stage workers may have removed the cell cap (Bailey and Ball, 1991). It is a heterothallic organism and develops a characteristic spore cyst when opposite thalli (+ and-) fuse. Spore cysts measure 47-140pm in diameter. Spore balls enclosed within the cyst are 9-19pm in diameter, and individual spores are 3.0-4.0x1.4-2.0pm (Shimanuki et. al., 2000).
CBD can reduce colony productivity by lowering the number of newly emerged bees, and in some cases may lead to colony losses. The disease is found infecting honey bee brood in most regions of the world, including warm and dry climates. Clinical symptoms of chalk brood often appear for only a short time, typically under cold and damp weather conditions (Aronstein and Murray, 2010).
Stone brood disease (SBD) is Caused by Aspergillus flavus or Aspergilla’s fumigatus, also affects larvae after capping, first they appear white and fluffy but later become hardened and either a pale brownish or greenish yellow. There are no treatments available for this disease but it does not usually affect strong healthy colonies (Bailey and Ball, 1991)
The fungus erupts from the integument of the insect and forms a false skin and at this stage, the larva may be covered with green, powdery fungal spores. The spores of A. flavus are yellow green, those of A. fumigatus are gray green, and those of A. niger black. These spores can become so numerous that they fill the comb cells containing the affected larvae (Shimanuki et. al, 2000).
Amoeba disease is adult caused by Malpighamoeba mellificae a single-celled parasite that affects the abdomen (OIE, 2008) and excretory organs (malpighian tubules) of adult bees. All castes are susceptible, but drones and queens are rarely infected. This disease of the digestive system of adult honeybees is caused by the protozoan Malpighamoeba mellificae. The parasite affects malpigian tubules of honey bees and shortens the life cycle of bees. After ingestion, the cysts of the amoebae germinate and migrate to the Malpighian tubules. After 18 days, the amoebae, after consuming many epithelial cells, form cysts that are soon after liberated from the tubules and then voided (Mike, 2014).
The disease is spread similarly to Nosema, with which it is often found as a mixed infection. It is not considered to cause colony mortality, but may be serious because it impairs the functioning of the Malpighian tubules, which act as the kidneys of the bee. The diagnosis of the disease can only be done microscopically, but an apparent inability of healthy-looking colonies to build up may indicate infection. No control chemical is registered and good management practices are the only measure to adopt (Mike, 2014). The existences of amoeba diseases and its distribution were studied and reported in Ethiopia (Gezahegn Tadesse and Amssalu Bezabih, 1991).
Nosema apis is one of the most important adult honeybee pathogen (OIE, 2008). The repercussions of infection with this parasite have been considered to equal or exceed the losses caused by all of the other diseases, including the more easily diagnosed brood diseases (Michael, 2008). Nosema occurs in adult bees and spores of nosema are ingested with the food and germinate in the mid gut of the bee. Each sends out a long thread, known as the polar filament, which penetrates the cells lining the gut. The living 'germ' of the spore passes through this filament and into a gut cell. Here the organism multiplies and soon fills the infected cells with spores (Mike, 2014).
Note of the editors: This picture was deleted due to copyright issues
Figure 3. Nosema apis infecting the abdomen of bee
In Ethiopia the survey was conducted and nosema was reported in low infestation (FAO, 1989). Survey conducted in 58 districts of Oromia, Amhara, Southern Nations and Nationality and Peoples (SNNP), Tigray, Gambella, Benishangul -gumuz, Somale regional state of Ethiopia, Nosema apis were identified the species causes nosematosis with 37.3% of infection rate (Amssalu Bezabih and Desalegn Begna, 2005).
The genus Varroa is the only genus in family Varroidae and currently is made of only four species namely Varroa jacobsoni Oudemans, which was firstly described to infest Asian bee Apis cerana, Varroa underwoodi found in Apis cerana in Nepal, Varroa rinderi found to infest Apis koschevnikivi from Borneo and Varroa destructor which was described to parasitize Apis cerana and Apis mellifera and also was once known as Varroa jacobsoni (Genersch and Aubert, 2010).
A) Varroa destructor
Varroa are ectoparasites that feed on the haemolymph of immature and adult honeybees and the world's most devastating pest of honeybees, Apis mellifera. Although the Varroa complex includes multiple species, V. destructor is the species responsible for the vast majority of the damage attributed to mites from this genus. However, taxonomic work (Anderson and Trueman 2000) indicated that a previously unidentified species of Varroa destructor was responsible for the damage to Apis mellifera. Since that time, the mite has spread around the world and has become nearly cosmopolitan in distribution. Those countries not hosting Varroa maintain strict quarantine procedures to lessen the chance of an accidental importation of the mite.
The adult bee is only an intermediate host and a means of transport for the mite. The female mite ingests small quantities of adult haemolymph but, to stimulate laying egg, she must consume larval haemolymph (Mary, 2007). Mites can live for several months on adult bees. The rate of infestation depends on brood ratio and the age of the mite. However, most mites enter brood cells for reproduction a few days after they have been released into the colony. Varrroa destructor is more distributed in the world now (James and Zettel, 2010).
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Figure 4. World distribution of varroa destructor
Source: Adapted from (James and Zettel, 2010).
The Life Cycle of Varroa
The life cycle of varroa has two stages, first the phoretic stage, mites ride on adult workers or drones, at the same time feeding on blood (haemolymph) from bees, usually from the intersegmental membrane on the abdomen. Second the phoretic stage lasts about 5-11 days when there is brood in the colony. Of course, mites are forced to remain phoretic if there is no brood, and this can last 5-6 months in cold climates. Mites experience higher mortality during the phoretic stage. The phoretic stage is important for mites to transfer horizontally to other colonies, by being accidentally dropped onto flowers and then picked up by other foragers, by mite-carrying bees drifting to another colony, or finally by bees robbing a colony dying from mite infestation (Zachary, 2012).
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Figure 5. Life cycle of varroa destructor
Source: Adapted from (Christian, 2016).
B) Tracheal Mites (Acarapis Woodi)
Tracheal mite is caused by Acarapis woodi which infests the respiratory system of adult honeybees. Tracheal mites can infest all castes - queen, workers and especially drones. Mites usually infest adult bees when they are less than 3 days old, but older (up to 10 days) bees are also susceptible, particularly within the winter cluster (Williams, 2015). Acarine disease could persist in the colony for years causing little damage, but combined with other diseases or unfavorable conditions, the disease increases the mortality of colonies.
A. woodi is a tracheal mite affecting the respiratory system of honey bees, causing the disease acarapisosis. These microscopic mites measure 150 pm in length and feed on the haemolymph of their hosts. They enter, live in and reproduce in the large prothoracic tracheae of all bees, but can also be found in the head, thoracic and abdominal air sacs (OIE, 2012).
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Figure 6. Honeybee trachea infected by Acarapis woodi, Approx. 150 pm in length.
Source: Adapted from (James and Zettel, 2010).
Life cycle of tracheal mite and distribution
Tracheal mites will infest all castes of a honeybee colony including workers, drones and queens. The invading mites are attracted to the current of expired air coming from the first thoracic spiracle. Once inside the host bee, after 1 or 2 days the female mite lays 5 to 7 eggs over a period of 3 to 4 days. Eggs hatch in 3 to 4 days and progress through a larval stage, then a nymph stage before finally reaching adult form. The male takes 11 to 12 days to fully develop, whereas the female takes 14 to 15 days to fully develop. The female is capable of laying almost one egg a day, each of which is about two thirds the weight of the female herself. As many as 21 offspring from each female is possible (Douglas, 2011).
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Figure 7. World distribution of Acarapis woodi.
Source: Adapted from (Douglas, 2011)
The most commonly known honeybee diseases reported to exist in Ethiopia are Nosema, Amoeba and Chalk brood diseases (Desalegn Begna and Amssalu Bezabih, 1999; Desalegn Begna, 2006). Furthermore, research review of different times in Ethiopia indicates that investigations of about 16 different types of pests and three microbial diseases are found in the country (Desalegn Begna, 2015).
Honeybees are infected with fungal, bacterial and protozoan pathogenic organisms (Haylegebriel Tesfay, 2014). Honey bee diseases, predators and pests are problems for bee keeping practice in Ethiopian. Field diagnostic surveys and laboratory analysis works has been conducted to identify and characterize honeybee diseases and pests associated with local honeybee of Ethiopia Honey bee diseases in Ethiopia include Chalk brood diseases caused by pathogenic fungi, Ascosphaera aphis, Nosematosis caused by Nosema apis and amoeba caused by a single protozoa Malpighamoeba mellificae (Desalegn Begna, 2015, Haylegebriel Tesfay, 2014). Some major types of honeybee pests and predators, magnitude of their damage, and some possible solutions to minimize the damage they cause on bees and their products were deliberated (Desalegn Begna, 2001). The economic loss associated with the presence of honey bee diseases and pest was estimated in some works and significant loss was reported.
The study was conducted in East Wollega Zone, Oromia Regional state at about 332km away from Addis Ababa, and the capital city of Ethiopia. It is bordered on the southwest by Buno Bedele Zone, on the west by the Didessa River, which separates it from West Wollega, on the northwest and north by the Benishangul Gumuz Region by the northeast by Horo Guduru Wollega, on the east by West Shoa, and on the southeast by the Gibe River which separates it from Jimma Zone. The zone is located in the area stretching from 36 0 30'00” to 36 0 45'00''longitude and 9 0 05'00'' to 9 0 15'00'' latitude with elevation ranging from 1000m to 3207m. The range of annual rainfall of the zone is from 1500mm to 2200mm with mean annual temperature 15-20 degree centigrade (CSA 2005, 2007). The study was specifically conducted in two districts; Diga and Wayu Tuka.
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Figure 8 Map showing the location of the study area.
(Source: Ethiopia: Oromia Region Administrative Map, 2013)
Diga district is one of East Wollega Zone, Oromia Regional State. The Woreda is located at about 346 km away from Addis Ababa and 15km from Nekemte town to the West. Based on agro-climatically conditions namely: Highland altitude ranges 2100-2342m and Midland ranges 1200-2100m with annual rainfall of 2400mm (Josha O,et al; 2010, CSA 2007).
The study was conducted in Wayu Tuka district in east Wollega Zone, Oromia Region. Wayu Tuka district is located 324 km from the capital Addis Ababa at an altitude of 1700-2200 m above sea level and has an average annual rainfall of 2400 mm (CSA 2007).
In this study, both primary and secondary sources of data were used. The primary data was collected from sample household beekeepers through a semi-structured questionnaire (Appendix, 1), field examination and laboratory diagnosis of adult worker honeybees and brood. Secondary data was obtained from various sources through desk review.
The data collected comprises both qualitative and quantitative data that generated by questioner survey and laboratory diagnostic. Quantitative data comprise, age, family size, number of colony owned, amount of honey harvested, prevalent and incidence rates of honey bee disease and pests, while sex, educational level of respondents, types of hives owned, colony placement, constraints of beekeeping, trends of colonies were taken as qualitative data.
A multistage sampling procedure was employed to select beekeepers and honeybee colonies. In first stage two districts were selected from the administrative zone using purposive sampling method based on their possible for beekeeping potential and accessibility. In second, stage six rural villages (six beekeeping site) selected from each districts based on their potential beekeeping. In the third stage, twelve beekeepers were selected in each rural village and two honeybee colony samples from each beekeeper sites were selected using random sampling method.
In total 146 beekeeper respondents' 68 beekeepers from Wayu Tuka district and 78 beekeepers from Diga district were taken. The beekeeper samples were based on owning honeybee colonies with frame box and transitional beehives from both districts. The information of each beekeeper was collected from secondary sources, mainly from Livestock and fishery bureau of the study districts. The beekeeper should maintain colony without absconding in order to take sample twice from his or her honeybee colonies for the study.
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Figure 9 Flow chart of sampling strata of Diga and Wayu Tuka districts.
In order to examine the prevalence and infestation rates of the onset of diseases and pests, two honeybee colonies considering each 146 beekeeper as one apiary site, totally 292 honeybee colonies samples were taken from both districts. The beekeeper should be 2km-5km far distant from each other as apiary site parameter and the samples were collected two times: on dry season (January or February), and wet season (June or July)). The internal and external inspection was done to collect data on the health status and samples of adult honeybees and broods were taken for laboratory diagnoses. Finally, prevalence for apiary level and infestation/infection for colony level was calculated using (Vanenglesdorp et al., 2013) protocols:
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Frame box or transitional bee hives opened and Colonies were internally examined for brood and adult bee disease with symptom of American and European foul brood disease, Chalk and Stone brood disease and Varroa destructor and other pests.
The presence of small hive beetle and wax moth were identified through its adult, larvae or pupae and colony examination methods as described by (Neumann et al., 2013). Larvae of SHB have pairs of prominent brownish dorsal spines on each segment with 3 pairs of anterior prologs. The larvae of wax moth has no spines, but number of setae(hairs) on each segments with 8 pairs of prologs (3 pairs,4 pairs and 1 pairs on anterior, abdominal and last segments respectively (Ellis et al., 2013). Unlike Small hive beetles, it produces silken galleries.
The study followed the standard methods for Varroa detection (Dietemann et al. 2013).Samples of adult bees were collected from honeybee colonies hived in frame box and transitional beehives. From each bee colony, 250 adult honeybees were brushed off from the brood comb directly into a wide mouth plastic container. The collected adult bees were killed using 70 % ethyl alcohol and placed in 10 ml of 1% detergent-water solution (10 ml detergent in 1000 ml water) and vigorously shake for 1 minute to dislodge mites. The mites were collected filtering the solution through a ladle (8- to 12-mesh) that hold the bees back and let out the mites with the solutions. Then, wire gauze was used to hold the mites back and discharge the solutions. The wire gauze was turned down to white paper on which the presence/absence of the mite was examined and counted.
Furthermore, brood examinations were done by cutting off 5 X 5 cm brood comb areas from drone and/or worker pupae broods. About 100 pupae were randomly removed from their cells using forceps and checked for the presence of varroa mites on the worker and/ or drone pupae. Number of varroa mites observed in both diagnosis (adult and brood) were recorded.
Samples of 20-30 adult honeybees collected from colonies at random. The sample of honeybee were preserved by adding 70% alcohol.The head and first pair of legs of honeybees were removed using scissor. Transverse-section thoracic disks were sliced and placed directly in a small bottle containing 10-percent potassium hydroxide (KOH). The sliced thoracic disks in KOH were heated and stirred gently near to boiling point for approximately 10 minutes until the soft internal tissues dissolved to expose trachea rings. The trachea ring sections were retrieved through filtration and washed with tap water. The disk-trachea suspension were examined for infested under microscope at 10 magnification power (Sammataro et. al, 2013).
As these two diseases affect the abdominal contents of adult honeybees, their sampling and diagnostic techniques are almost the same. Therefore, bee samples collected for either of the two can help to tell the condition or status of the other (OIE, 2008). Hence, following the (Fries et al., 2013) procedure, asample of 30-60 worker adult honeybees were collected from the hive entrance.
The sample bees were collected in 70% alcohol until laboratory analysis. The abdomen of honeybees from each sample was cut using scissors. The cut abdomens were placed and grounded in mortar containing 5-10ml distilled water until an even suspension is formed using pestle. The mortar and pestle were thoroughly cleaned before being used again. A loop of suspension were placed on microscopic slide using the sterilized loop and covered with cover slid. Then suspension was examined under light microscope using 40 magnification power.
The chalk brood mummies were checked at the bottom board of hive entrance, in thecomb cells and on the ground beneath the hive entrance. Mummies were moistened withdistilled water and the supernatant was placed on microscope slid, covered with cover slid andexamined under light microscope for spores and/or spore balls and cysts of Ascosphera apis (Jenssen et al. 2012) .
Field diagnostic procedures for AFB and EFB were used based on the (OIE 2008) procedure. During the early stages of decay until about three weeks after death, the dead larvae have a glue-like consistency. To test for the AFB disease, larvae that would be discolored, exhibits a melted appearance, ropness (the larvae can become glutinous in consistency and can be drawn out as threads when a probe is inserted into cell); hard and dark scales that adhere strongly to the lower sides of the cell and protruding tongue were checked for its presence.
The most significant symptom of EFB is the color change of the larvae. They change from a normal pearly white to yellowish, then to brown, and finally to grayish black; they can also be blotchy or mottled. Infected larvae lose their plump appearance and look undernourished. Larval remains often appear twisted or melted to the bottom side of the cell. Unlike larvae killed by AFB, recently killed larvae rarely pull out in a ropy string when tested with a toothpick. The dead larvae form a thin, brown or blackish brown scale that can be easily removed. Therefore during field diagnosis, all clinical symptoms were checked.
The collected data were stored in Microsoft Excel and SPSS software programs (SPSS @, version 20) for analysis. The statistical analysis used in the study varied depending on the type of variable and information obtained. Summarized data was presented in the form of tables and figures.
The data collected through semi structured questionnaires were analyzed using descriptive statistics and the ranking of the different types of beekeeping constraints, Common Cause of honeybee colony and yield decrease, control method of bees from agrochemicals and the effect of pest and predators on honeybee colonies obtained in the study were done by using the rank index formula as described by (Musa et al., 2006):
Rank index=sum of (5 X number of household ranked first + 4 X number of household ranked second + 3 X number of household ranked third + 2 X number of household ranked fourth + 1 X X number of household ranked fifth) for an individual reason divided by the sum of (5 X number of household ranked first + 4 X number of household ranked second + 3 X number of household ranked third + 2 X number of household ranked fourth + 1 X number of household ranked fifth) for overall reasons.
Based on the data collection and laboratory diagnosis method the following result was recorded during the study period (figure 10).
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Figure 10 Field examination and laboratory diagnosis procedure and results.
Of 146 sample households, about 2.9% and 97.1% were female and male headed in Wayu Tuka district respectively and 3.8% and 96.2% were female and male headed in Diga district respectively (Table 1). The survey result indicates that beekeeping activity in the study area was practiced dominantly by male. This is an agreement with the finding of Teklu Gebretsadik (2016) who indicate that beekeeping is more of male's occupation due to traditional bee hives are hanged on tall tree branches where female could not access and manage. The result also related to (Alemu Tsegaye, 2015) results of the study, the majority (91.1%), of sampled respondents were males and the rest 8.9% were females.
About 70.6% of respondent's age in Wayu Tuka district ranges from 18 to 42 years and (76.9%) of respondent's in Diga district aged between 18 to 42 years (table 1). This result shows that beekeeper in the study areas were more in productive age. The survey result indicated that marital status of most beekeepers in Wayu Tuka (89.7%) and Diga (88.5%) were married.
The result concurs the finding of (Guesh Godifey, 2015) who indicate that people in the most economically productive age are actively engaged in beekeeping activities. These is also in agreement with (Challa Kinati, 2010), in that people in most productive age are actively involved, accommodating experiences from elders and finally become independent beekeepers in his study area.
About 32.4%, 22.1% and 7.4% of respondent beekeepers in Wayu Tuka district have attended elementary, secondary school and diploma respectively while 38.2% of respondent beekeepers cannot read and write. Similarly about 44.9%, 19.2% and 1.3% of the beekeepers in Diga district have attended primary, secondary school and diploma respectively and remaining 34.6% of respondent beekeepers cannot read and write (table 1). Beekeeping activity in the study area was practiced by both educated and non-educated beekeepers, but beekeepers with better educational background are more productive since they are quicker adopters of beekeeping technologies than that of non-educated ones.
Education status of beekeepers affects their chances of shifting from traditional beekeeping to modern technology beekeeping (Kidane Mollaw, 2014). Therefore, beekeeper would be interested to innovations to boost bee production hence, profit level; all other factors remaining unchanged. So that the educational level of the beekeepers were taken as a good proxy indicator of management abilities. It was assumed that those who have attained secondary or primary level education might be better skilled and productive than those without formal education. Education increases the ability of beekeeper to access and use information relevant to the beekeeping. A higher level of education was therefore expected to increase the production level (Ajiao and Oladimeji, 2013).
Concerning to occupational status of respondents, 95.6% in Wayu Tuka and 96.2% in Diga districts were farmers. The family size were small (39.7%, 32.1%) and medium (50.0%, 42.3%) in Wayu Tuka and Diga districts respectively (table 1). Most of beekeepers practice beekeeping as side of crop production in the study area.
The result indicate that the family size of the respondents were large and as study indicated by (Workneh Abebe et al., 2008) beekeepers with large family size have interest to accept improved beekeeping technologies. Also the study by (Guesh Godifey, 2015) states that that labor is one of the important factors to their beekeeping practices.
Table 1. Socio- demographic characteristics of households
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As the result shows in (Table 2) most parts of the study area were farm land (55.65%), and forest land (3.35%) in the study districts however some of respondents home land area was surrounded by forest and natural resource conservation area. As study by (Pongthep, 1990) states that the beekeeper seeks to place his colonies in or near areas where a sufficient quantity of honey plants, be they crop or pasture plants, weeds, shrubs, forest trees, roadside planting exists, in season or throughout the year. Planting special crops for bees is not likely to yield a good economic return. Beekeeping is therefore one of the rare forms of agriculture in which the planting of crops is not in particular vital.
Table 2. Vegetation type of Diga and Wayu Tuka Districts.
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The mean land holding of the sample respondents was 2.60 and most of the sample respondents at the time of study use their own mean of land by dividing 2.17, 0.11 and 0.3 for farm, natural resource conservation and for grazing respectively (Table 3).
Table 3. Land holding and land use of the respondents in Diga and Wayu Tuka Districts
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Majority of the respondent did not practice bee forage plantation (59.6%) in both Diga and Wayu Tuka districts during the study period and only (40.4%) of house hold beekeeper participated in bee forage plantation practice (table 4). This Poor bee forage management resulted to weak colonies that are more susceptible to various honey bee disease and pests and honeybee colonies absconding during dearth period. Due to these and other reasons, beekeepers of the study areas were suffering from loss of their honeybee colonies. Less honeybee forage planting practice of beekeepers in the study area during the study period were attributed to number of factors of which the main ones are shortage of farmland and improved bee forage seeds.
Bee forage plantation can be important for increasing the beekeeping potential since beekeeping is dependable on environmental suitability of an area than any other livestock production (Nuru Adgaba, 2006). Honeybee population and their productivities mainly influenced by the nature of honeybee flora of an area (Birhanu Tesema, 2016). Without bee forages it is difficult to establish apiary and maintain honey bee colony strong and healthy.
Table 4. Bee forage farming practice
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The major factors that hinders household beekeeper for bee forage farming practice were lack of improved bee forage seed (28.1%), shortage of farm land (17.2%) and soil fertility problems (15.8%) in the study area (figure 11).
Not only bee forage there is different factors cause agricultural productivity to decrease. These are weather, the capacity of a given farm, pests, available equipment, the supply and demand in the market (Wise G, 2015).
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Figure 11 Factors affecting bee forage planting in the Diga and Wayu Tuka.
Based on respondents and visual observation the beekeeping activities in Wayu Tuka and Diga districts have been practiced sideline with other agricultural activities. There were no any respondents who depend only on beekeeping. Most beekeepers in Wayu Tuka and Diga districts were started beekeeping before 2000(3.80%), 2001-2005 (10.89%), 2006-2010 (18.41%) and after 2011(28.03%) in increasing respectively (table 5) and this indicate these beekeepers were related within age of between 31-42 years. Based on household respondents, beekeeping practice was increasing in the study area with beekeeping technology. Majority of beekeepers started after year 2011.
Table 5. Beekeeping starting time in the Diga and Wayu Tuka
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Before beginning beekeeping, beekeeper decides on source of honeybee colonies according to availability. In the study area during interview with respondents, the result revealed that the capture of natural swarms (54.8%) was common technique which was practiced almost by all beekeepers in the study area and others got honeybee colonies from their parents and both (from parents and catching swarms) source, 31%, 25%, respectively as a source of colony for honey bee colony increase (Table 6).
The result is related to the study by (Asaminew Tassew, 2015) that indicates the sources of colonies were mainly by catching swarms and gifts from parents, but, nowadays catching swarms and buying colonies are the common practices.
Table 6. Source of honeybee colonies in Diga and Wayu Tuka Districts.
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Based on respondent’s frequency, there were two major active seasons and one less active season. This was based on estimation of respondent by flowering season majority of honeybee flora species of the area flower in first (September to November) in Diga (51.1%) and (53.6%) in Wayu Tuka and in the second season (December to February) in Diga (31.4%) and 29.6%) in Wayu Tuka districts. These indicate there were two main honey flow season, the next honey flow season (end of May to June) and March to early May was dearth period during the study periods (figure 12).
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Figure 12. Season of active and dearth periods in Diga and Wayu Tuka Districts.
According to beekeeper household the amounts of traditional beekeeping and their products decreasing while transitional and modem beekeeping increase but the honeybee colony population was decreasing. In terms of beekeeping system, frame box and transitional beekeeping with product is increasing due to awareness of honeybee management system and most of beekeepers were shifting traditional beekeeping to transitional and frame box beekeeping (figure 13).
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Figure 13. Trends of honeybee hive type, colony number and honey productivity 4.2.9. Purpose of beekeeping and Placement of honey bee colony
Based on the results in the study area all respondents keep honeybees for honey as general (61%) and few of them for both honey and wax (39%) (Table 7). There were no household beekeeper keep honeybee colonies for other honeybee products.
Majority of the beekeepers (28.90%) in the study areas placed their honeybee colonies at the backyard where as about 16.32 % of the beekeepers placed then honeybee colonies at different selected sites. The other beekeepers placed their honeybee colony in backyard and selected apiary sites (9.8%) (table 7).
Table 7. Placement of honey bee colony in Diga and Wayu Tuka Districts.
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Similar description with (Guesh Godifey, 2015) in selected zones of Tigray region, majority of the beekeepers (76.3%) in the study areas placed their honeybee colonies at the back yard where as about 12.5 % of the beekeepers placed their honeybee colonies at closure areas (protected areas). The rest placed in inside house (10.9 %) and hanged on trees found near to the home (0.3%). However according to (Etenesh Mekonen, 2016) most of the beekeepers in Ade'a Berga district kept their hives at back yard for simple management and day to day service for beekeepers.
Based on majority of respondents the trend of honey bee colony and its Products was decreasing in traditional, transitional and frame box beekeeping (31.80%) without any harvest (4.18). Some of beekeepers also respond to honeybee colony and yield increasing (19.25) and others responded to stable (table 8). Based on visual observation during survey most of the respondents (5.86) were shifting their traditional beekeeping to transitional and frame box beekeeping system. This decrease is more obvious in area since there is no more practice of queen rearing. Sometime the colony population and products was decreasing with various factors. As the result of data, most beekeepers faced with shortage of food for their honey bee colony and faced with no products.
Table 8. Trends of honeybee colony and products in Diga and Wayu Tuka Districts.
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In the study area there were an increase in honey bee colony population and products in each respondent’s site because of the use of new technology of beekeeping (52.05%), use of new technologies with availability of good market price (25.34%) and availability of good marketing bee products (22.60%) and the use of both (figure 14).
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Figure 14. Cause of increasing honey bee colony population and products.
Majority of the respondents states the cause of honey bee colony and yield decrease by ranks were lack of bee forage (as 1st), pest and predators (as 2nd) and Honeybee diseases (as 3rd) and others (Table 9) and all these cause the decrease in productivity and honeybee colony population.
The result is agreement with (Kerealem Ejigu et al., 2009) shortage of bee forage is ranked first due to population pressure, lack of land use policy and the high demand for farmlands put pressures on mountainous areas to be used for crop production and livestock grazing. These create deforestation, soil erosion and irreversible ecological degradation. Moreover, burning of undergrowth and destroying of forestland for expansion of farmland could trigger a reduction of honey producing floras and foraging areas.
Absence of the bee flora calendar in most parts of the country is another severity to the development of honeybee feeding development strategies. Cultivation of bee forage is not practiced in the country. This problems results critical honeybee forage scarcity and hindering the production and productivity increment of honeybee in the country. Absence of the bee flora calendar in most parts of the country is another severity to the development of honeybee feeding development strategies (Mulisa Faji and Fekadu Begna, 2017).
Application of chemicals such as fungicides, pesticides and herbicides hinder the productivity and production of honey bee colonies. Deforestation was under way in some parts of the districts and this cause one of the problem raining season irregularity that reduces nectar and pollen source for honeybee colonies.
Honeybee colonies and their products are susceptible to various diseases, parasites and pests. The honey bee disease is serious problem on honey bee colony population and productivity. The major types of honeybee pests and predators, magnitude of their damage, and some possible solutions to minimize the damage they cause on bees and their products were discussed in Ethiopia (Desalegn Begna, 2001).
Shortage of bee forage causes the honeybee colony to abscond to areas where resources are available for their survival. Shortage of bee forage directly associated with off flowering period of major honeybee forages. The respondents reported the occurrence of sever feed shortage following harvesting time. Almost all sample respondents indicated that there is no provisions of supplementary feeds at the time of sever feed shortage. This is relating with the traditional practices of forest beekeeping. From this we can conclude that, in the study area honey bee colony population and production were in a decreasing trend (Kidane Mollaw, 2014).
Table 9. Cause of honeybee colony and yield decrease in Diga and Wayu Tuka Districts.
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Index = Sum of (5*ranked 1st+ 4* ranked 2nd+3* ranked 3rd+2* ranked 4th+1* ranked 5 th) for individual reasons divided by the sum of (5*ranked 1st+ 4* ranked 2nd+3* ranked 3rd+2* ranked 4th+1* ranked 5th) for over all reasons.
Similarly with (Desta Abi, 2017) indicated that the Presence of honeybee pests and pathogen, prevailing bad weather (prolonged precipitation and freezing and heavy wind speed etc.), Lack of knowledge and skill of honeybee Pest and diseases control, application of agrochemical (direct spray of pesticide on bee visited agricultural crops), Shortage of bee forage, poor or absence of practice of hive shading, Lack of practice of Hive inspection and Shortage of improved hive types were ranked in the decreasing order of their importance.
Among all constraints of beekeeping, these natural bee enemies were known to cause great damage to honeybee colony life and products. In the study area the major pests and predators considered as challenges ranked with their relative degree of importance were ants, beetles, wax moth (figure15), honey badger, bee eater birds, dead hawks moths, bee lice and some predators like, lizards, wasps and spiders (table 10).
The result is current with (Bekele Tesfaye et al., 2017), report in assessment of pests and predators in Bale zone, pests and predators were a major challenge to the honeybees and beekeepers in the study area and respondents were reported that the presence of Honey badger, spider, bee-eating birds, bee lice, Beetles, wasps. Death Head hawks moth. Mice and lizards in order of their decreasing importance.
Table 10 . Honeybee pest and predators in Diga and Wayu Tuka Districts
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Index = Sum of (5*ranked lst+ 4* ranked 2nd+3* ranked 3rd+2* ranked 4th+l* ranked 5th) for individual reasons divided by the sum of (5*ranked 1 st+ 4* ranked 2nd+3* ranked 3rd+2* ranked 4th+l* ranked 5th) for over all reasons.
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Figure 15 Major pests and predators in Diga and Wayu Tuka Districts
In the study area majority of respondents honeybee colony and products was more affected in traditional bee hive (51.4%), transitional bee hives (30.1%) and modern bee hives (18.5%).The less affected of honeybee colonies in the frame box and transitional bees hives is due to ease operation of bee disease for control (table 11). According to (Guesh Godifey, 2015) traditional beehive is more prone to honeybee pests and predators followed by both transitional and improved frame bee hives equally.
Table 11. Effect of honeybee disease on types of hive.
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The term pesticide covers a wide range of compounds including insecticides, fungicides, herbicides, rodenticides, molluscicides, nematicides, plant growth regulators and others (Wasim et al., 2009). In the study area agrochemical was used to manage agricultural products at farm land and storage area. The major agrochemicals in use are pesticide and herbicide.
Based on survey result all respondents (100%) were using agrochemicals to increase yields of agricultural products, to protect at store and less spoilage during storage. However, the use of certain agrochemicals has also been associated with some important environmental and ecological problem (Govinda, 2014).
Based on agricultural activity of the area majority of the respondents uses agiochemicals for weed control (47.3%), crop pest control (23.3%), Malaria Control (15.8%) and (13.7%) for tsetse fly control (Figure 16).
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Figure 16. Agrochemical application in in Diga and Wayu Tuka Districts
A factor that has received a lot of attention has been the use of pesticides in agriculture, particularly insecticides. Insecticide sprays were responsible for a number of fatal incidents with honeybees and the introduction of new insecticides must reduce (Oliver, 2012). The application of agrochemical is occurring in the summer season and usually due to agricultural misuse of certain pesticide products (AFSSA, 2009).
Agiochemicals (pesticides and fertilizers) are looked upon as a vehicle for improved crop production technology though it is a costly input. Balance use, optimum doses, conect method and right time of application of agrochemicals ensures increased crop production. The requirement of fertilizers and pesticides for crops differ according to soil and meteorology (Bhandari, 2014)
The agrochemicals most frequently used by respondents were 2, 4-D (24.9%), Malathione (11.6%), Roundup (19.2%), DDT (10.2%, Mancoze (12.1%). hi the area fanners serve as the main unit of pesticide application. Hence, their degree of awareness of pesticide residues that affects honeybee colony was their methods of pesticide application (Figure 17).
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Figure 17. Types of Agrochemicals in Diga and Wayu Tuka Districts
Pesticides include chemically synthesized compounds, devices or organisms that are routinely utilized in agriculture to manage, destroy, attack or repel pests, pathogens and parasites. Pesticides include both organic and inorganic moieties and may be classified into different groups based on their chemical composition (Govinda, 2014).
The trend of agrochemical application was increasing and the local controlling from honey colony also takes place by fanners. Based on the result the effect of honey bee colony and yield lost decreasing from year to year due to awareness of beekeepers (Table 12).
Acute exposure to pesticides can kill individual honey bees and entire colonies immediately or within hours of exposure. Chronic pesticide exposure may include lethal and sub lethal effects on the brood, workers, drones, and queen, who may be killed or rendered infertile. Within an individual bee, certain pesticides and their associated metabolites can attach to, alter, or destroy cells in the gut, brain, or other tissues, thus affecting the bee’s physiology and behavior. Sub lethal effects of pesticides include physiological effects that impact enzyme activity and brain activity, leading to impairment of olfaction, learning, and memory; and behavioral effects on motor activity leading to alterations in navigation, orientation, and feeding behavior (Ellis, 2017).
Agrochemical applicators must determine if there is a clear hazard to managed populations of honey bees. Potential exposure of honeybees to pesticides can vary greatly depending on the type of pesticide, formulation, application method, label restrictions, and other factors. The goal in using agrochemical is to achieve maximum benefit (success) with minimum negative impact, and these factors should always be considered in pesticide selection (J. D. Ellis, et al., 2017).
Table 12. The effect of agrochemical application on beekeeping in in Diga and Wayu Tuka Districts.
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The concern therefore, is that low levels of exposure may affect the normal functioning of bees such that it is a threat to the honey bee colony population. These concerns about the potential for sub-lethal effects are theoretically valid and the European Food Safety Agency concluded that sub-lethal effects could not be fully excluded in worst case situations (EFSA, 2012). However to date, there is no overwhelming evidence from “real-life” situations that any of them cause serious problems.
Total 146 household representatives were interviewed during the survey for local control of agrochemicals from honeybee colony by ranking indicate as 1st adjusting season of spraying (before flower blooms), 2nd adjusting time or hour of application, and 3rd feed their colonies during application (Table 13)
Table 13.Local control method of agrochemicals in Diga and Wayu Tuka Districts.
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Index = Sum of (5*ranked 1st+ 4* ranked 2nd+3* ranked 3rd+2* ranked 4th+1* ranked 5th) for individual reasons divided by the sum of (5*ranked 1st+ 4* ranked 2nd+3* ranked 3rd+2* ranked 4th+1* ranked 5th) for over all reasons.
Respondents themselves were the main agent of agrochemical application in the study area. Therefore the awareness of agrochemical application and control method reduce the negative effect on honeybee colony and yield. Whether they apply pesticides in a standardized method affects the generated amount of pesticide residues, thereby ultimately influencing the safe production of agricultural products (Bo and Linhai, 2010).
The global colony losses of A. mellifera are believed to be caused, in part, by parasites, pathogens, and pests. The decline of honeybee populations is of great concern in Ethiopia. In this study of 146 beekeeping sites and 292 honeybee colonies were examined for major honeybee parasites (varroa mites, bee lice and tracheal mites), adult honeybee diseases (Nosema and Amoeba) and brood diseases (Chalk brood, American Foul brood and European Foul brood) with their prevalence and infestation rate in the study area. However AFB, EFB, SBD and tracheal mite did not confirmed during the study period.
In this study of 146 beekeeping sites and 292 honeybee colonies were examined to determine the prevalent and incidence rate of chalk brood disease and Ascosphaera apis the causative agent Chalk brood spore was confirmed (figure 18). From the examined beekeeping site to determine the prevalent of chalk brood disease was 26(17.4%) and 34(30.4%) were confirmed during dry and wet season, respectively. From the total of 292 honeybee colonies examined for the incidence of chalk brood disease 49(13%) in dry and 53(17.9%) in wet season were recorded during the study (table 14). The reason of prevalent and incidence rate of chalk brood disease was significantly (p<0.05) higher in wet season may be due to the growth of fungal related with wet condition.
Table 14. Prevalent and incidence of Chalk brood disease
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The prevalent and incidence rate of Chalk brood disease was limited during the dry season. The growth of chalk brood in the honey bee nest appears to be enhanced by high moisture (colonies not well ventilated in high humidity situations), cool temperatures, and colony stress. This is similar description with (Lopes et al, 2015), the fungal Ascosphaera apis, that occurs in bee larvae's (A. mellifera) is usually more prevalent in the spring ( Europe) and since the growth is enhanced in cool and damp place.
The incidence of Chalk brood is more prevalent during the spring, once the development of fungi is favorable in cold and wet hives (Flores et al, 1996). The result is similar with (Desalegn Begna, 2000; Guesh Godifey, 2015,) that stated that humidity favors the multiplication of fungus.
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In both Diga and Wayu Tuka districts, 146 beekeeping sites and 292 honeybee colonies were assessed for the prevalence and infestation of Amoeba (Malpighamoeba mellificae) disease. The prevalence was recognized in beekeeping site 113 (77.4%) in dry and 119(79.7%) wet season. From 292 honeybee colonies, 200 (78.4%) and 243 (81.8%) honeybee colonies were infected during dry and wet season respectively (table 15).
The incidence rate of amoeba disease in dry and wet season in Diga and Wayu Tuka districts were not significantly different (P > 0.05). This indicates that the incidence of amoeba disease may be depending on colony population and agro ecology.
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The result showed that Malpighamoeba mellificae pathogen was occurred throughout the year. The same result reported by (Amssalu Bezabih et al., 2010) indicated that Amoeba disease was reported to be widely distributed and identified in most places of the country throughout the year. The difference in prevalence and infestation level of amoeba disease was affected by agro ecology and temperature. The result contradicted with the finding by (Amssalu Bezabeh and Desalegn Begna, 2012) who reported that highest cyst number (infestation) in the months of April and August (high humidity) and lowest intensity in the month of January (high temperature) was recorded.
Diagnosis made on honey bees in field and laboratory at Addis Ababa reported a prevalence rate 73% of amoeba prevalence. The diseases was also reported with high prevalence rate in different regional state of Ethiopia such as; Oromia region with prevalence (88%), Amhara region (95%) and 60 % in Benishangul- Gumuz (Aster Yohannes et al., 2010).
In the study area 146 beekeeping sites and 292 honeybee colonies were examined for the prevalent and incidence of Nosema apis and it was confirmed (figure 19) in Diga and Wayu Tuka districts. From 146 apiary sites examined for the prevalent of nosema during the study were 64(43.8%) sites in dry and 122(63.6%) sites in wet season. The incidence rate also tested that out of 292 colonies 137(34.8%) tested positive in dry and 173 (52.6%) tested positive in wet season (Table 17). The incidence rate of nosema disease in Diga and Wayu Tuka districts was significantly (p<0.05) higher in wet season than dry season. The difference of incidence rate of nosema disease may be due to the humidity condition. The incidence of nosema disease was high in wet season due to availability of moisture for the growth of nosema spore in the hive.
Table 16 prevalent and Incidence rate of Nosema apis in inspected apiaries and honeybee colonies.
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According to study by (OIE 2013) justify the infestation level increase when bees are confined, such as in the autumn and winter in colder climates because the disease is transmitted among bees via the ingestion of contaminated comb material and water, and by trophallaxis; honey stores and crushed infected bees and Nosema can cause problems during winter Months when bees are confined within the hive for long periods (Marla and Gary, 2016). Nosema levels generally increase when bees are confined, such as in the autumn and winter in colder climates when the amount of brood is decreasing and perhaps in the early spring when there is an increase in the brood (Webster, 1993).
The occurrence of Nosema apis was in agreement with (Bailey and Ball, 1991), who found that the pathogen was limited during the dry and the highest prevalence of Nosema apis was identified in wet season than dry season. Studies by (Manning et al., 2007) also shown that Nosema levels are lowest during the summer months, while they go up in spring or autumn.
Nosema disease is probably the most widespread of the diseases of adult bees (Michael, 2008). As an extremely low rate of infection by N. apis was found in each season) and, nosema disease occurs wherever bees live. However the prevalent of Nosema apis was high in wet season than dry season in the study area. In the central highlands of Ethiopia, highest infestation level of Nosema apis and spore number per individual honey bees was reported in the month of August and September by (Amssalu Bezabih, and Desalegn Begna, 1998).
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Nosema spores (bean shaped) and Amoeba cysts (circle shaped)
Figure 19. Laboratory examination of Nosema apis and Malpighamoeba mellificae.
Varroa originally evolved in Asia, on a different species of honeybee, the Asian honey bee (Apis cerana), and has since spread to the western honey bee (Apis mellifera') throughout most of the world. According to (Paul, 2012) Varroa is now present in almost all honey bee colonies at different levels of infestation that are always increasing unless treated.
A) The Prevalent of varroa destructor
From the total of 146 sample of apiary sites examined for the prevalence of varroa, 110 sites (69.6%) and 84 sites (60.9%) were positive to varroa mites in adult bees during dry and wet seasons, respectively. Similarly, from the total of 146 beekeeping sites examined in sealed brood, Varroa mites positive 86(56.5%) in dry and 72 (52.2%) in wet season (Table 17). The result indicate that prevalence of Varroa mites was higher in dry season (59.7%) than in dearth period (43.8%) (p<0.05).
Table 17 The Prevalent of varroa destructor
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B) The incidence rate of varroa destructor
From the total of 292 honeybee colonies examined for incidence of Varroa mites in adult bees, the incidence rate recorded during dry and wet seasons was 200 (78.5%) and 170 (69.6%), respectively(table 18). The varroa destructor incidence was limited during wet season. The incidence was higher in dry season than wet season. The difference in incidence rate in dry season may be due to more availability pollen source for brood rearing since brood rearing depend on bee forage availability in the area and the result indicate that, the incidence rate was higher (p<0.05) in dry season than in wet season.
Table 18. Incidence rate of Varroa destructor
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N=Number of beekeeping sites and honeybee colonies examined, +Ve= Number of honey bee colonies found positive
Varroa mite incidence rate was high and related with brood population which is higher at active season or dry season than in wet season (table 17). According to (Guesh Godifey, 2015) the causes of variation in prevalence might be attributed to different factors such as ecological variability, season and management aspects.
The reason as discussed by (Paul, 2012) observed that the mites prefer nursing honeybees, which tend to stay in brood combs. The increased rates of prevalence and infestation of colonies under honey production may be due to the greater presence of drone cells in these colonies in the period with greater abundance of food. The numbers of varroa offspring generated in a brood cell depends on the time the cell remains capped. As the new adult bee emerges from the brood cell, the parent mite and the female mite offspring are released. The parasitized honey bee brood will emerge weakened with a shortened lifespan.
The varroa mite population recovery was also reported in the drier months of January and March attributed to lower brood rearing during dry season (Desalegn Begna et al., 2016). The study also conducted by (Desalegn Begna 2015) during the fall season from October to November 2010, during which the numbers of mites reach high point.
Varroa destructor poses an increasing global threat to the apicultural industry and agricultural ecology; however, the issue of whether certain environmental factors reflect the level of mite infection is far from resolved. Moreover, mite infection in honeybee colonies was positively correlated with temperature but negatively correlated with humidity (Genet, 2016).
The high prevalence of varroa mite infestation on both brood and adult bees is terrible problem to beekeeping and honey production practice of area unless an appropriate management practices is instituted to minimize the well-known weakening and devastating effect of Varroa mite infestation (Adeday Giday et al., 2017).
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Figure 20. Laboratory examination of brood for Varroa.
From the total 146 apiary sites examined for the prevalence of Braula coeca, 21(26.1%) and 7(13.0%) had lice during dry and wet seasons respectively (Table 19).
Table 19. Prevalent of bee lice in inspected apiary sites
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N=Number of apiary sites examined, +Ve= Number of sites found positive
Incidence Rate of Bee lice From the total 292 honeybee colonies examined for incidence of Braula coeca, 32(21.9%) and 26(17.8) of them were infested during dry and wet seasons, respectively (Table 20). The prevalence of bee lice was higher during dry season due to more Population of honeybee colonies than in wet season (P<0.05)
Table 20 Incidence rate of bee lice
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The overall prevalent of bee lice (21.9%) observed in the current study was much greater than other previous reports in Ethiopia. The present result was higher than report of (Gidey Adeday et al., 2012) who indicated the prevalence rate of 4% in adult honey bees. However, the current finding was less than the report by (Gemechu Gizachew et al., 2013), who found 42% lice prevalence in and around Holata.
The study by (Guesh Godifey, 2015) also indicate that from the total 87 apiaries the prevalence of Braula coeca, is 43(49.4%) and 15(17.4%) during honey flow and dry seasons respectively. Some report by (Belie Tessega 2009), also indicate bee lice infestation is 105 (27.5%) and 22(5.73) of them during honey flow and dry seasons, respectively. The bee lice prevalence, the highest (46.5%) was observed in movable frame hives (Alemu Tsegaye, 2015). This higher bee lice prevalence in modern hives might be associated with the modern hives', kept close with minimal spacing, exposure to drifting and robbing.
However according to (Gizachew Gemechu et al., 2013) highest prevalence of bee lice observed in the strong colony than of weak colony is not in agreement with other previous studies, and might be different method of categorizing the colony status. Different level prevalence of bee lice was observed among the different study sites, between medium land and high altitude areas, between apiary and backyard management system, and between types of hives and the difference is due to environmental factor like temperature.
According to (Abd et al, 2008) the infestation rate began to increase rapidly in winter season reaching maximum rate of 16.2%, 15.8% and 17.4% for A. m. carnica and 22.6%, 23.9% and 22.9% in December of 2004, 2005 and 2006, respectively.
Beekeeping is an important to rural communities by providing a variety of goods honey, wax, pollen, royal jelly, propolis in particular and enriching ecosystem by pollination. However honeybee colony and its products decrease due to honeybee health, poor management, lack of improved bee equipment, lack of bee forage, absconding and improper application of agrochemical.
The most common pests and predators revealed in the study area were ants, beetles, wax moths, dead head hawks moth, bee eater birds and honey badgers and these were major problems on honeybee colony health and product in the study areas.
Honeybee disease like American Foulbrood, Europian Foul brood, Stone brood diseases and tracheal mites do not confirmed in the study area however the common parasites and pathogens such as Braula coeca, Varroa destructor, Nosema apis, Malpighamoeba mellificae, and Ascosphaera apis were confirmed in areas.
In terms of the prevalent and incidence, Nosema apis and Ascosphaera apis were more prevent with higher incidence rate in wet season than dry season , however varroa destructor were more prevent with higher incidence rate in dry season than wet season and the amoeba disease was common in dry and wet season.
Furthermore, based on laboratory and survey result the most common honeybee diseases and pests, Amoeba, Nosema, chalk brood diseases and varroa destructor were identified with their different prevalence and infestation within dry and wet season during the study period.
According to the result of this study, some of the suggested issues that require consideration by beekeepers and any development organizations are high lightened below:
-I- To save honeybee colony form agrochemicals, beekeeper and others in mind chemicals which are not harm full to honey bees and the application should not match with flowering season to minimize the poisoning effect on honey bee.
-I- Scientific information of honeybee pests and parasites in addition, standards evaluation of honeybee disease and pest with their prevalent/incidence rate is needed to evaluate the health of honeybee colonies.
-I- Awareness creation for beekeepers in terms of internal and external inspection for honeybee disease symptoms and report the status to laboratory for diagnosis.
-I- Beekeepers should maintain strong and healthy honeybee colonies enable the natural prevention of honeybee from disease and pest.
-I- For the reason of time restraint in this study, farther study on economic threshold of honeybee disease and pests is suggested by monitoring throughout the year.
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Appendix Table 1 Local control practices of honeybee pests and predators
Abbildung in dieser Leseprobe nicht enthalten
Appendix Table 3 Questionnaire for Beekeepers
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