Honeybees and bumblebees: weather impacts on pollinator activity in Irish orchards

Honeybees and bumblebees exhibit differing responses to weather conditions in Irish apple orchards. Honeybee activity, including foraging and pollen collection, is highly sensitive to temperature, solar radiation, and wind speed, peaking at 20°C and declining with high humidity and wind. Bumblebees show greater resilience, with activity less affected by weather extremes, particularly at lower temperatures and higher humidity. Solar radiation negatively impacts honeybee flight, possibly due to diurnal timing constraints, while bumblebees’ larger eyes may enhance foraging under low light. Relative humidity reduces pollen foraging in both species, but bumblebees maintain activity longer. Wind speeds above Beaufort 2 significantly reduce honeybee activity but not bumblebee foraging. The study highlights functional complementarity, where bumblebees can compensate for reduced honeybee activity in adverse weather, underscoring the importance of pollinator diversity for ecosystem resilience under climate change. Findings support the need for diversified pollinator management in agriculture.