Bumbles like it hot

The idea that insects seek out flowers with the most pollen or nectar or pollen might not be quite correct.

Researchers at Cambridge University and Queen Mary College, London have discovered that bumblebees prefer to visit warm flowers and can use colour to predict the bloom's temperature. Why they should want warm flowers is unclear, but they might be using warmer blooms to help maintain their body temperatures and save energy.

The finding may also throw light on the evolutionary link between plants and pollinators:

“About 80% of flower species have a peculiar structure in their flowers; the skin is made up of little cells that are cone-shaped. It has never been fully understood what function they served,” Professor Chittka said.

“But one effect it does have is that the cones act as little lenses to focus light directly into the parts of the cells that contain the floral pigment; because more light is absorbed it warms the flowers -- that's a clever trick.

“We think the fact that 80% of floral species have this, it could be a broad evolutionary innovation in order to generate warmth and thus lure pollinators to collaborate with them,” he suggested.