When you see a Spring Azure butterfly, imagine a covetous Cleopatra.
The ancients cherished this brilliant hue of blue with a hint of green, so like the sky on a clear day. The word azure comes to us by way of Lazheward, the Persian name for the region of Afghanistan where lapis lazuli has been mined for over 6,000 years.
The world’s first synthetic pigment may have been “Egyptian blue“, but artists from that African empire carved sacred scarabs and other symbols of royalty and eternal life from imported lapis lazuli. The stones are prominent among burial gifts. Cleopatra mesmerized Caesar and Anthony with eyes shadowed with powdered lapis lazuli.
What if Cleopatra, seeing this magical creature flashing the color of life and nobility in mid-air, had the vain and devious thought to capture and powder it for her adornment? Nature has an answer for such hubris! The scales of the butterfly’s wings would grind down to a translucent white glop. You see, the Spring Azure has not a bit of its namesake pigment.
The iridescent dazzle of the Spring Azure comes from nature’s nanotechnology. The Spring Azure boasts a “structural color,” meaning its wing scales have an elegant microscopic architecture that reflects very specific wavelengths of color. Textile manufacturers have already mimicked this trick to make fabrics that never fade or dull, while bankers are weighing how structural colors might make currency harder to counterfeit. And yes Cleopatra, “photonic cosmetics” is an emerging industry. The most exciting prospect, however, is a new information revolution that takes cues from nature to create transistors based on light rather than electricity.
The following video is a great introduction to this field of research:
While Spring Azures are easy to spot across a field, they’re pretty rare in the big city. Seek them in woodlands and open fields in our parks, or in gardens. Females often deposit their eggs on dogwood tree flower buds and lower to the ground in blueberry bushes and New Jersey tea. Males hang out near mud puddles and the mucky edges of stream banks and ditches. Both sexes feed on the nectar of rock cress, winter cress, dandelions, buckeyes, and violets.
If you’d like to boost your chances of spying a Spring Azure, please consider volunteering for the Butterfly Project NYC, donating to the organization, and going on field trips.