Scientists say that bumblebees like it hot and learn to use the color of plants to select blooms with the warmest nectar. Through trial and error, bees learn which flowers are the hot spots that offer and additional reward in the form of heat or energy for pollinating insects.
Scientists tested bees with four different colored artificial flowers with varying temperatures, the majority of the bees chose the darker colored, warmer flowers; and when the colors and temperatures were switched, the bees still preferred the warmer colored blooms.
When bees go off to collect nectar, they are attracted to colours of flowers which act as signals for them about the type of flower colours that provide more or less nectar. They will favour certain colours over others according to track experience, this means that if they have found yellow flowers to provide more nectar they’re more likely to visit yellow flowers and will favour certain colour over others.
What colors do bees like?
Bees have the ability to distinguish colors, they have a trichromatic color vision — that means that bees can see the three primary colours of blue, green and violet or Ultraviolet (UV) spectrum and tend to view things in ultraviolet patterns. Bees cannot see red.
The article “How bees see their world” puts it like this:
“Although both honey bees and people have a visual system based upon three-colors, the limits of this color sensitivity are very different. People cannot see very far into the Violet or Ultraviolet region of the electromagnetic visual spectrum. We are essentially blind to wavelengths of light below 400 nanometers/millimicrons (light in this regions is called UV-A and UV-B light). These are the powerful light rays which cause us to tan or sunburn. Bees can see these invisible-to-us rays of light! Another interesting difference happens at the opposite end of the visible spectrum. We can easily see the color of a red sweater or red fire engine (at least many of them used to be red!). To a honey bee, however, the color red is invisible. They see red objects as black, or the absence of color.”
How do bees see their world?
Bees have five eyes. First of all, worker honey bees have those two eyes that are great ellipses on opposite sides of their head. Each compound eye is made up of about 6,900 individual hexagonal units called ommatidia. Each ommatidium captures light rays from a small angle of view. The rays are focused by several lenses onto light sensitive pigment. Once stimulated, these sensory cells pass along nervous impulses coding information on the quality of the light to the optic nerves which eventually reach the the honey bees’ brain. Found on top of their head are three ocelli (simple eyes with a single lens) arranged in a triangular pattern. These simple eyes tell the bee of the changes in light intensity and help the bees get to and from the nest at dawn and dusk.
Source: “How Bees See Their World” – GEARS Carl Hayden Bee Research Center