Impact of climate change and drought threat on the honey bees food collection

Climate change and the growing risk of drought pose a serious threat to pollinating insects and their food resources. The aim of the study was to analyse the effect of changing climate and weather conditions, as well as drought risk, on food collection by honey bees (Apis mellifera L.) from apiaries located in areas assigned to two classes of drought risk - DR (Drought Risk) and NDR (No Drought Risk), based on the Selyaninov hydrothermal coefficient. Data collected from 60 apiaries in Poland during the growing season (April-September) in the years 2018, 2019,and 2022 were used to analyse the differences in hive scale parameters, i.e. weight changes, ambient temperature and humidity, between the two drought classes. The GLMM results showed significant differences in climate parameters between the DR and NDR classes, which influenced food collection by the honey bees. DR apiaries, with higher ambient temperatures and lower ambient humidity, displayed significantly smaller changes in hive weight in the months with the greatest drought (July-August) than apiaries in NDR zones. Monitoring climate change and its impact on ecosystems, including on bees and their food resources, is crucial for planning and carrying out mitigation actions against the consequences of drought. Solutions preventing food deficiencies for pollinating insects must be implemented, including enrichment of the landscape with drought-tolerant plant species providing nectar and pollen, as well as increasing water resources essential for plants and animals.