干旱区生态环境知识资源中心

Survival rates were monitored among three honey bee subspecies under two ecological regions within Saudi Arabia; Riyadh characterized by desert climate and Albaha resembling semiarid climate. Frequency of colony losses were counted and categorized within three temperature ranges of maximum monthly temperatures (20-28, 29-37 and 38-46 degrees C) for 24 months. Out of 420 colonies included in this study, 101 colonies were able to survive during the whole period of assessment. Survival rates among subspecies were highly associated with temperature ranges (chi(2) = 40.6, df = 4, P < 0.001) and were significantly different between both ecological regions (chi(2) = 10.6, df = 2, P < 0.005). Most of these losses (76%) occurred in summer months, August and September, when average maximum monthly temperature ranges between 38-46 degrees C. The highest losses were recorded in exotic honey bee subspecies; Apis mellifera carnica (92%) and Apis mellifera ligustica (84%), compared to (46%) in the local honey bee colonies, Apis mellifera jemenitica. Apparently extreme ambient temperatures during the summer season are highly detrimental to exotic honey bee colonies. Additionally, Varroa mite and Nosema spp. were the main pests that can contribute to colony losses throughout the period of the study. Results indicate low tolerance of the exotic honey bee subspecies to temperatures extremes of Saudi Arabia during the summer, thus selection and conservation of the indigenous honey bee race is highly demanded.