Pollination is in danger Flowers in gardens are not enough for many insects to survive
Flowers in the garden are good, but not enough: a Zurich study shows that pollination by beetles and hoverflies is at risk without interconnected green spaces.
18.05.2026, 10:33
18.05.2026, 14:56
SDA
For the study, researchers from the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) analyzed the occurrence and behaviour of pollinating insects in 24 gardens in the city of Zurich, as the research institute announced on Monday.
Volunteers recorded and caught every flower-visiting insect for nine hours at a time over the course of a month. The researchers compared gardens in differently densely populated parts of the city and with a different range of flowers.
Bumblebees always find flowers
The result: large wild bees such as bumblebees found their way to individual flowering gardens even in densely built-up inner cities. Hoverflies and beetles, on the other hand, were less likely to be found in such areas, regardless of the availability of flowers in individual gardens.
The researchers cite the lack of suitable habitats at neighborhood level as the reason for this. Hoverflies require large areas of greenery, while many beetles rely on dead wood as a breeding ground. As a result, plants that depend on pollination by these insect groups produce fewer seeds and fruits in densely populated urban areas.
According to the researchers, the results make it clear that the efforts of individuals are not enough. Private garden owners could achieve a lot. "It is always worth doing something for biodiversity in a small area," ecologist David Frey, who led the experiment, was quoted as saying in the press release.
