Bumblebee colonies are adversely affected by the largescale cultivation of maize, according to a study published last week (November 19) in the Journal of Applied Ecology.
Researchers at the University of Göttingen in Germany found that bumblebee colonies placed experimentally in environments dominated by maize gained less weight and collected fewer pollen types than colonies placed in landscapes of mostly rapeseed. The negative effect became more pronounced as the percentage of land covered by maize increased.
The researchers suspect that the results are due to the fact that, compared to some other crop types, maize fields contain “far fewer wild herbs,” study coauthor Teja Tscharntke says in a statement. “Insufficient growth, as shown here with bumblebees, is also to be expected with other insects, in particular those that rely on flowers.”
To offset the effects of maize on colony growth, the team advises land managers to plant strips of flowering plants or hedges alongside their crops.
A.L. Hass et al., “Maize-dominated landscapes reduce bumblebee colony growth through pollen diversity,” J Appl Ecol, doi:10.1111/1365-2664.13296, 2018.