The objective of this study was to estimate the loss rates of honey bee (Apis mellifera) colonies in six consecutive winters (2016-2017 to 2021-2022) in five states of the semi-arid high plateau region of Mexico, as well as study the factors associated with these losses. The survey included data from 544 beekeepers and 75,341 colonies. The colony loss rate differs significantly (p < 0.0001) between the winters analyzed and fluctuates between 14.9% and 30%, with an average of 22%. Colony losses were unaffected (p > 0.05) by migratory beekeeping practice and operation size, but losses were significantly affected by Varroa monitoring and control (p ≤ 0.001). The types of loss differ among the winters analyzed. In the winters of 2016-2017 to 2018-2019, beekeepers attributed higher loss rates to unresolved problems related to the queen (e.g., a queenless colony, poor laying), but in the winters of 2019-2020 to 2021-2022, the highest loss rate was the result of problems such as diseases, poisoning, and absconding (leading to dead colonies or empty hives). The results reveal high loss rates in the region studied, as reported by beekeepers from other countries. It is suggested that strategies should be implemented to improve the quality of queens, the control of varroasis and other diseases, and the degree of Africanization.
Keywords: Apis mellifera; COLOSS survey; Mexico; colony losses; risk factors; winter mortality.