Diagnostic study on major honeybee disease, pests and predators in North Western Ethiopia.

BACKGROUND: The study was conducted in Pawe district from Benishangul-Gumuz and Jawi and Fagita Lekoma districts from the Amhara region to investigate major honeybee pests, predators and diseases. METHODS: Using a purposive sampling technique, 183 households were interviewed, and 240 samples were collected for laboratory analysis of bee disease; data were analysed using descriptive statistics. RESULTS: The share of hive types owned by sampled respondents was 88.6%; overall, 1.1% and 10.3% were traditional, transitional and modern beehives, respectively. About 92% of the sample respondents acquired their base colonies by catching swarm bees on the apex of trees. The majority of beekeepers executed external inspections of their colony, whereas only 50% carried out internal inspections. Based on the responses of beekeepers, around 48.9%, 56.3% and 23.1% of colonies absconded every year from Pawe, Jawi and Fagita Lekoma districts, respectively. Ants, wax moths, bee lice, beetles, spiders, birds, monkeys and honey badgers were the major honeybee pests and predators discovered in study areas in decreasing order. Concerning the incidence of Varroa mites, Nosema apis and amoeba disease, 27.5%, 60% and 71.6% of samples showed positive results in study locations, respectively. CONCLUSIONS: From this result, we observed that ants, wax moths, bee lice, beetles, spiders, birds, monkeys and honey badgers were the major honeybee pests and predators. The prevalence of amoeba disease was comparatively higher in highland areas and in the summer season. This finding suggests the need for the alertness of beekeepers in controlling bee disease and pests and strengthening bee colonies through seasonal colony management. There should be a strict quarantine, and check-up undertaken when a new colony is purchased from one region to another is essential.

Evaluating the Impact of Commonly Used Pesticides on Honeybees (Apis mellifera) in North Gonder of Amhara Region, Ethiopia.

Global honeybee losses and colony decline are becoming continuous threat to the apicultural industry, as well as, for food security and environmental stability. Although the putative causes are still unclear, extensive exposure of bees to pesticides could be the possible factor for worldwide colony losses. This study was aimed at evaluating the impact of nine commonly used pesticide incidents on adult worker honeybees (A. mellifera) under the laboratory condition, in North Gonder of Amhara region, Ethiopia. Feeding test, contact test, and fumigation tests were carried out for each pesticide following the standard procedures, and each pesticide toxicity was compared to the standard toxic chemical, dimethoate 40% EC (positive control), and to 50% honey solution (negative control). The results revealed that all the tested pesticides caused significant deaths of the experimental bees (P < 0.05) in all the tests when compared to the negative control. Diazinon 60% EC, endosulfan 35% EC, and malathion 50% EC were appeared highly toxic causing 100% mortality of bees, while chlorsulfuron 75% WG killed 90% of the experimental bees as tested via feeding. On the other hand, agro-2, 4-D and its mixture with glycel 41% EC are moderately toxic, and mancozeb 80% WP and glycel 41% EC were slightly toxic to honeybees as compared to the positive control (dimethoate 40% EC). Suddenly, diazinon 60% EC and malathion 50% EC triggered 100% mortality of bees, while endosulfan 35% EC and chlorsulfuron 75% WG caused 63.63% and 90.82% of bee mortality, respectively, when evaluated via contact test. The fumigation test also showed that chlorsulfuron 75% WG, diazinon 60% EC, and endosulfan 35% EC caused 100%, 86.7%, and 65.6% mortality rate of bees. Our result also highlighted that tested LD50 of all pesticide incidents were significantly lower than the manufacturer-based LD50. This shows that local honeybees A. m. jemenetica are extremely sensitive to commonly used agricultural pesticides, which may affect the colony level due to the intensive application of these pesticides in Ethiopia.

Performance evaluation of local honey bee race (Apis melifera secutellata) in the Metekel Zone of North Western Ethiopia.

BACKGROUND: Honeybee colonies differ in performance due to variations in their traits in terms of production, productivity and behaviour. The objective of this study was to identify and evaluate the performance of honey bee race at their geographical location. METHODS: A total of 20 honey bee colonies from traditional hives were transferred into frame hives and arranged randomly with enough space between the colonies. Colonies were evaluated for aggressiveness, hygienic behaviour, brood area, pollen and nectar stores, absconding and honey yield. RESULTS: The results indicated that colonies were generally aggressive, and the majority of colonies at 2.3-m away from the entrance reacted to the external body. They removed 95.7% ± 0.75% of the pin-killed pupae in 24 h, and there was significant (p < 0.05) variation among the different observations. The average population of the brood was 24.925 ± 7.714 unit area of brood/hive during the honey flow period. Similarly, the area allocated for storing pollen grains could reach up to 11.46 ± 3.96-unit area of pollen/hive. The swarming and absconding behaviour of the race was on average 3.39 ± 0.6, and 25% queen cells were found during the breeding season and dearth period, respectively. On average, the 8.85 ± 0.54 kg honey yield per colony per harvest on one honey chamber box was nearly similar to the national average (19.4 kg/hive/year) when harvested two times per year. CONCLUSION: In general, the Apis mellifera secutellata race is good in hygienic tendency and also performs well for honey yield under optimal management practices. The absconding and aggressive behaviour was high; the main reasons were extreme weather condition, and different pest and disease, seasonality of bee flora were the major ones. So, based on the current findings A. m. scutellata was predominantly available in the area and highly productive if well-managed. On the other hand, we are recommended on dearth period management and on the height of shade bee colonies.