Bangalore scientists decode insect's choice of flower

How do the bees and flies pick up appropriate flowers to land in search of food?

Biologists in Bengaluru have cracked the code to unlock the secrets behind the insect behaviour, which could have potential implication to make farming climate-resilient in the future.

While it is known that pollination happens when bees, bumblebees and hoverflies fly from one flower to another, how these insects identify the suitable flowers remains unknown.

Bengaluru to Sweden

Biologists stumbled on the answer after experimenting with flower lookalikes in Bengaluru, Sikkim and Sweden.

"The question we had was if the flowers are different across the world, how can the same pollinator (a fly or bee) that lives across the world find all these different flowers," said Shannon B Olsson, the leader of the National Centre for Biological Sciences team, which carried out the study along with their collaborators from the Uppsala University, Sweden. The researchers found while some combination of colour, shape and odour attract the insects everywhere, there are also site-specific patterns that work in a specific surrounding only, suggesting the role environment plays in shaping the behaviour of a fly or a bee.

"Our results show one can attract pollinators to artificial objects that do not directly resemble real flowers, but possess combinations of attractive cues.

"If one wants to attract pollinators to an area like an agricultural field better, using lures could be helpful," Olsson said.

During the course of the experiments, the flower look-alikes were able to attract 150 visits in Sikkim, 112 in Uppasala and 146 in Bengaluru.

"If we put lures with real flowers that do reward the insect with sugar or pollen, the artificial flower signature could potentially help bring the pollinators in to a feeding place like flowering crops. It's like displaying fake food at a restaurant counter," she told DH.

The reason why scientists are interested in the problem is due to a decline in the pollinating insect population due to habitat loss, environmental change, pesticide use and disease.

But more than 80% flowering species need animal pollination for flowering.

"Our work could help determine if a butterfly garden created in the USA could be effective in India," said Olsson.

Also finding cues that work across environments and climates can help create climate-resilient systems.

“One could potentially use our ideas now to test ways to improve the attraction of pollinator towards crops, but this would require specific experiments,” she added.

The findings have been published in the November 27 issue of Proceedings of the National Academy of Sciences.