June 20, 2013
Flower Patterns Play Role In Bumblebee Choices
Lee Rannals for redOrbit.com — Your Universe Online
Researchers writing in the journal Naturwissenschaften - The Science of Nature discovered bees prefer radial patterns when looking for food.
The team performed a couple of experiments using both radio-frequency identification technology and video recordings. They exposed over 500 flower-naive bees to two types of patterns on artificial clay flowers, pitting concentric patterns against radial. Concentric patterns are composed of circles or rings with the same center, while radial patterns are distinctly colored lines extending from the outside of the flower.
The patterns were placed in two positions on petals of the artificial flower, either central or peripheral. Researchers found both visual properties had significant effects on flower choice, but pattern type trumped position.
When they compared the influence of radial patterns in the center with the influence of radial patterns on the periphery, there was little difference in the bees' response. The team believes the visual cues from the radial pattern helped guide bees to the periphery of the flower.
"Which came first: the chicken or the egg? The behavior of bees has been shaped over the course of evolution as adaptations to flower appearance," the researchers wrote in the journal. "Equally, floral appearance has evolved in ways that cater towards bees' visual and olfactory abilities. Flowers may be taking advantage of a principle that will be familiar to students and teachers alike: the bees need not be shown the food itself, but rather, how to find it."
Last year, scientists wrote in the British Ecological Society's journal Functional Ecology that Velcro-like cells on plant petals play a big role in helping bees grip flowers. The study focused on special cells found on the surface of petals and discovered conical cells help bees visit hard-to-reach flowers such as snapdragons. With this flower, bees have to land on a vertical face and pull open a heavy lip to reach the nectar.
“Nobody knew what these cells were for, and now we have a good answer that works for pretty much all flowers," said lead author Dr. Beverley Glover. “It is too easy to look at flowers from a human perspective, but when you put yourself into the bee´s shoes you find hidden features of flowers can be crucial to foraging success."
This study provides another perspective on how flowers may have adapted to help bees become better pollinators.