Butterfly Wings in a New Light

May 25, 2020
butterfly on a branch.

A study of reflective wing scales by researchers from Harvard and Columbia, including HUCE Faculty Associate Naomi Pierce, reveals new dimensions of their function and beauty

Harvard Magazine

By Bennet McIntosh

To hold a delicate butterfly harmlessly, conventional wisdom advises, softly pinch its wings together. Because butterflies depend on taste receptors on their feet to find food and a suitable nest for their eggs, it's wiser, the theory goes, to handle appendages that are only as alive as toenails or hair.

But the story is not that simple. Far from inert membranes, butterfly wings hold intricate networks of veins, sensory cells, and often scent pads for releasing and spreading mating pheromones. This winter, a collaboration between Harvard and Columbia researchers revealed just how alive these wings really are—including heat-sensing cells and tiny "wing hearts" that pump fluids through their delicate veins. And the fact that butterflies seem to use the heat sensors, and microscopic structures on their wings that reflect and radiate infrared light, to stay cool, demonstrates that much of the world a butterfly experiences involves light beyond the visible spectrum.

Hessel professor of biology Naomi Pierce, who is Harvard's curator for Lepidoptera (moths and butterflies), met Nanfang Yu when the latter, then a postdoc, contacted her with an unusual research proposal. Yu was studying electrical engineering with Wallace professor of applied physics Federico Capasso, and had noticed that moths' feathery antennae bore an uncanny resemblance to structures for guiding infrared light, suggesting that moths might use them to "see" light outside the visible spectrum, perhaps for finding food or mates.

Read full article >>