Impact of War on the Winter Survival of Bee Colonies in Ukraine: Monitoring Results for 2023-2024

Over the last 17 years, Northern Hemisphere countries, including the United States, European countries, Canada, and Mexico, have reported significant rates of annual losses of honey bee colonies, Apis mellifera L. These losses have significant economic consequences for the beekeeping and agricultural sectors, and, primarily, for ecosystems. This study aimed to analyze the honey bee colonies losses after wintering 2023-2024 in Ukraine in the context of international monitoring coordinated by the COLOSS organization, under the conditions of the third year of the war. Data collection was carried out using a questionnaire designed by the COLOSS working group, adapted to Ukrainian respondents and supplemented by national coordinators. The sample size was 684 protocols. All administrative regions and physiographic regions of Ukraine, except Crimea were covered by survey. It was found that the total rate of honey bee colony losses in Ukraine after the wintering of 2023-2024 is 9.52 %, which does not differ significantly from the corresponding indicators for the previous two winterings: after the wintering of 2022-2023 - 10.75 %, after the wintering of 2021-2022 - 8.8 7%. Colony mortality was 5.2% (after the wintering of 2022-2023 - 6.5 %). Negative natural phenomena caused losses of 2.3%, and unsolvable problems with queens – 1.99 % of colonies (after the wintering of 2022-2023 – 1.27 % and 3.27 %, respectively). The lowest rate of colony losses was found in the mixed forest zone (4.8 %), while in the broadleaf forest zone – 10.6 %, in the steppe zone – 10.5 %, in the Ukrainian Carpathians – 9.3 % and in the forest-steppe zone – 8.3 %. Like ech year, most often the dead bee colonies had many dead bees into or in front of the hive (37.4 %), and the least often they showed features of starvation (5.9 %). 90 respondents keep their apiaries in areas affected by military operations. The apiaries of about 5% of the beekeepers have suffered various types of damage, and more than 3% of beekeepers have lost contact with their apiaries due a number of reasons related to the war. An inverse relationship between loss rate and size of the apiary has been shown, and for the first time, significantly lower losses have been identified in stationary apiaries compared to migratory ones. 14.2 % of colonies in the spring turned out to be weak, but with a productive queen. However, no significant difference in wintering success between apiaries with such colonies and without them was found. Almost all respondents (98%) treated their colonies againts Varroa mites. Amitraz-based drugs remain the most popular, as before. However, no correlation was found between the use of such agents and low colony losses.