Scientists from the University of Cambridge and the University of Bristol, both in the UK, say that plants use a special mechanism to ensure that pollinators can remain attached to their petals for prolonged periods of time.
Many experts have wondered as to how bees, for example, can hold their grip on petals even in strong winds, when they should slip and slide. The new study found that petals are outfitted with Velcro-like cells that ensure the legs of insects can gain a solid foothold.
Details of the work were published in the latest issue of Functional Ecology, a journal edited by the British Ecological Society. The team says that these specialized cells are part of the reason why many insects find certain plants more attractive than others.
Interestingly, the stunning structure of the cells in question can only be viewed under an electron microscope, since they are very small. The lead author of the new investigation was Cambridge Department of Plant Sciences professor, Dr. Beverley Glover.
Together with her colleagues, the expert developed a version of snapdragon that did not feature the special cells on its leaves. When bees were allowed to choose which of the two plants to pollinate, they selected the one that featured those mutant cells, since this provided them a solid grip.
“Many of our common garden flowers have beautiful conical cells if you look closely – roses have rounded conical petal cells while petunias have really long cells, giving petunia flowers an almost velvety appearance, particularly visible in the dark-colored varieties,” Glover explains.
“It’s a bit like Velcro, with the bee claws locking into the gaps between the cells,” she goes on to say.
But studying snapdragons was not very conclusive. These plants have a heavy lid covering their nectar, which the bees needed to pry open in order to get to the good stuff. As such, it made more sense to have the Velcro-like cells, since it would have been nearly impossible for insects to get the nectar otherwise.
“Many of our garden flowers like petunias, roses and poppies are very simple saucers with nectar in the bottom, so we wanted to find out why having conical cells to provide grip would be useful for bees landing on these flowers,” Glover explained.
The group discovered that the special cells are of great use even to simple plants. In strong winds, the tighter grip enabled the insects to continue feeding, and thus pollinating the plants.