Decline of honeybees and its consequences for beekeepers and crop pollination in western Nepal

Abstract

AbstractPollination service by insects is globally threatened, yet trends outside of Europe and North America are poorly understood. Therefore, in less-studied regions of the world, beekeeper records can provide valuable insights into changes in pollinator populations.We conducted a questionnaire survey of 116 beekeepers in 10 villages in the Jumla District of western Nepal, where the native honeybeeApis cerana ceranais widely kept as a managed honeybee. We complemented the beekeeper survey with field data on insect-crop visitation, a household income survey, and an interview with a local lead beekeeper.76% of beekeepers reported declines in theApis cerana ceranapopulation. 86% experienced declines in honey yield per hive, and 78% reported declines in the number of beehives per beekeeper. Honey yield per hive fell by 50% between 2012 and 2022, whilst the number of occupied hives decreased by 44%. Beekeepers ranked climate change and declining flower abundance as the most-important drivers of the decline.The drastic bee declines raise concerns for the future food and economic security of this region, where honey sales contribute to 16% of total household farming income.Apis cerana ceranaplays a major role in crop pollination and contributes more than 50% of all flower visits to apple, cucumber, and pumpkin.To mitigate further declines in this region, we promote the use of pollinator-friendly farming practices including more wild flowers and maintenance of native habitat areas, and well-insulated log or top-bar log hives to buffer bees against extreme temperature fluctuations, which are expected to worsen with climate warming.