Bumblebee populations rebound in Finland following warm May

An unusually warm and sunny May provided a promising start to the bumblebee summer in Finland. According to Janne Heliölä, a researcher at the Finnish Environment Institute, the development of nests began positively early in the summer, leading to a substantial number of eggs and larvae, which resulted in a large workforce of worker bees.

“Thanks to the hot May, the summer for pollinators progressed strongly,” Heliölä reports. The peak number of bumblebees was observed in July, but by August, their numbers had dwindled significantly. New queens were seen in sunflower fields in August, searching for winter hibernation sites.

Currently, only workers and male bees are left buzzing about; it is mainly the new queens that will survive underground until the next summer, with the rest of the colony dying off in the fall.

The Finnish Environment Institute has been monitoring bumblebee populations more closely through volunteers for the past five years. After a significant decline in bumblebee species in 2022, populations rebounded to average levels last summer, although the cause of the initial crash remains a mystery. This summer, bumblebees were spotted in greater numbers until late July compared to the previous year.

Finland is home to 37 bumblebee species, with 30 of them monitored in this initiative. Heliölä notes that among the common species this summer, the field bumblebee has been particularly abundant, as well as the bush and rock bumblebees.

Pollinators play a crucial role in agriculture and berry production. Without them, crops such as blueberries and lingonberries would not yield fruit. Heliölä emphasizes the importance of long-term monitoring, arguing that observing bumblebee populations can reveal insights about environmental conditions and climate change. Recently introduced EU initiatives aim to improve pollinator habitats, and Heliölä remains optimistic about the survival of bumblebees, noting their adaptability to different environments.