Tag Archives: Iridescent Beauty: Development function and evolution of plant nanostructures that influence animal behavior

Structural colo(u)r with a twist

There’s a nice essay about structural colour on the Duke University website (h/t Nanowerk). Long time readers know my favourite piece of writing on the subject is by Cristina Luiggi for The Scientist magazine which I profiled here in a Feb. 7, 2013 posting.

This latest piece seems to have been *written by Anika Radiya-Dixit* and it is very good. From the Oct. 27, 2015 Duke University blog posting titled, Iridescent Beauty: Development, function and evolution of plant nanostructures that influence animal behavior,

Iridescent wings of a Morpho butterfly

Iridescent wings of a Morpho butterfly

Creatures like the Morpho butterfly on the leaf above appear to be covered in shimmering blue and green metallic colors. This phenomenon is called “iridescence,” meaning that color appears to change as the angle changes, much like soap bubbles and sea shells.

In animals, the physical mechanisms and function of structural color have been studied significantly as a signal for recognition or mate choice.

Glover, one of the post’s authors, is a scientist who believes there may be another reason for iridescence,

On the other hand, Beverley Glover believes that such shimmering in plants can actually influence animal behavior by attracting pollinators better than their non-iridescent counterparts. Glover,Director of Cambridge University Botanic Garden,  presented her study during the Biology Seminar Series in the French Family Science Center on Monday [Oct. 26, 2015] earlier this week.

Hibiscus Trionum

Hibiscus Trionum

The metallic property of flowers like the Hibiscus Trionum above are generated by diffraction grating – similar to the way CD shines – to create color from transparent material.

In order to observe the effects of the iridescence on pollinators like bees, Glover created artificial materials with a surface structure of nanoscale ridges, similar to the microscopic view of a petal’s epidermal surface below.

Nanoscale ridges on a petal's epidermal surface.

Nanoscale ridges on a petal’s epidermal surface.

In the first set of experiments, Glover and her team marked bees with paint to follow their behavior as they set the insects to explore iridescent flowers. Some were covered in a red grating – containing a sweet solution as a reward – and others with a blue iridescent grating – containing a sour solution as deterrent. The experiment demonstrated that the bees were able to detect the iridescent signal produced by the petal’s nanoridges, and – as a result – correctly identified the rewarding flowers.

It’s worth reading the Oct. 27, 2015 Duke University blog posting to just to see the pictures used to illustrate the ideas and to find out about the second experiment.

*’written by Beverley Glover and Anika Radiya-Dixit’ has been changed to ‘Anika Radiya-Dixit’ as per information in a comment received November 27, 2021.