Posts Tagged ‘pollination’

Bee_eye.jpgThe eye of a honey bee (photo credits).

Flowers look very different to insect pollinators, such as honey bees, compared to what we mammals see.

As the photo on the left shows, bees have compound eyes.

How a bee sees patterns as a result of its compound eyes is wonderfully illustrated at Andy Giger’s B-Eye website.

Like humans, bees can perceive different colors. (This has been know for over 100 years.)

Unlike humans, however, bees can perceive ultraviolet (UV) light.

Thus, the pigments in flower petals that absorb UV light create patterns visible to bees, but that may be invisible to humans. (see photos below)

These patterns are sometimes referred to as “honey guides” or “nectar guides” that presumably serve to direct the pollinators toward the center of flowers.merge

Flowers in Ultraviolet is a fantastic website that illustrates this in dozens of flowers categorized by plant families.

It was Thompson and co-researchers in 1972 that first published a connection between chemicals called flavonols and patterns on flower petals that may attract insect pollinators.

Plant flavonoids may be the UV-absorbing pigments mostly responsible for the patterns that attract insect pollinators as discussed here.

Taking Photos of Flowers in UV

If you are interested in taking such UV photographs of flowers this is an excellent website to learn how and to see what you need to get started.

For another website on the science and practice of photographing the “invisible” please visit beyondvisible.com.

Flowers Use Several Strategies to Attract Pollinators

It’s clear that some plants have the petal equivalent to “landing lights” at airports to guide airborne pollinators such as bees to the flowers.

Plants also use nectaries and floral scents to attract pollinators. (Bees have odor receptors at the base of their antennae.)

Recent research has provided clues regarding how moths key into the scent of a flower, for example.

Bees apparently have pretty short (5 to 10 seconds) memories and, thus, use a combination of visual and chemical (volatiles) cues to locate flowers.

More on this subject can be found in an excellent review (PDF) of how pollinators recognize flowers.

These just in:

Flowers may also facilitate pollination by using a sort of petal “velcro”.

Video of bee landing.

Bees Recognize Human Faces Using Feature Configuration

“Landing Lights for Bumblebees”

Bees can solve complex mathematical problem.

Leaked Memo Shows EPA Doubts About Bee-Killing Pesticide

For further reading, here are some books about bees:
The Buzz about Bees: Biology of a Superorganism

The Life and Times of the Honeybee

Plan Bee: Everything You Ever Wanted to Know About the Hardest-Working Creatures on the Planet

Bottom Line: Many plant species have flower petals containing pigments that absorb UV light, producing patterns presumably visible to – and providing guidance to – insect pollinators, but not to humans (normally, non-pollinators).

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