October 12, 2010

Flowers That Are Red, Striped Attract Bees

Gardeners could help out the declining worldwide bee population by planting flowers that are red or have stripes along the veins, UK researchers announced on Monday.

Experts from the John Innes Centre (JIC), an institute of the Biotechnology and Biological Sciences Research Council (BBSRC), studied the foraging patterns of bumblebees on a field of snapdragon plants located near the British city of Norwich.

By comparing the number of visits the insects made to each plant, they were able to determine that bees made more frequent trips to the red-colored flowers and those with venation patterns than white, pink, or non-striped varieties. The bees also visited more flowers on each of the target plants as well, JIC researchers report.

"Stripes following the veins of flowers are one of the most common floral pigmentation patterns so we thought there must be some advantage for pollination," JIC Professor Cathie Martin said in a statement. "Stripes provide a visual guide for pollinators, directing them to the central landing platform and the entrance to the flower where the nectar and pollen can be found."

"We examined the origin of this trait and found that it has been retained through snapdragon ancestry. The selection pressure for this trait is only relaxed when full red pigmentation evolves in a species," she added, noting that bees typically return to flowers where they had previously discovered food.

Bees, which play an important role in agriculture by pollinating crops and other plant life, are in the midst of a global population decline. Known as Colony Collapse Disorder (CCD) or Honey Bee Depopulation Syndrome (HBDS), this phenomenon has been observed in the U.S. and in several European countries. No official cause has been pinpointed, though various factors, including viruses, fungal infections, environmental changes, malnutrition, and pesticides, have been suggested.

During a presentation at the UK's Science Media Centre in June, Living with Environmental Change Program Director Andrew Watkinson called the effect of CCD on the bee population "catastrophic" and, according to BBC News, said that there was no one factor that could explain their decline.

"There's a whole range of agriculture and land use, disease, environmental change [and] pesticides," he added, according to BBC Science Reporter Katia Moskvitch. "To tackle a complex problem like the decline of pollinating insects, where there are a number of potential causes, requires wide-ranging research."


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