The bright glow of the Firefly's tail has always been a mystery. Scientists have succeeded in unraveling the mystery — at the protein structure level — of the mechanism at work in the glowing tail of the “Genji firefly” (Luciola cruciata Motschulsky), which is considered to have the highest luminous efficiency of any known source of illumination. By changing the the chemical composition of luciferase (a bioluminescent enzyme), the research team succeeded in changing the emission color from its normal greenish-yellow to orange and red. Researchers are now attempting to recreate the blue glow of the sea firefly (Vargula hilgendorfii) and firefly squid (Watasenia scintillans) in order to have all three primary colors at their fingertips.

When energy is converted to a light there is some loss due to heat, incandescent light bulbs have only 10% efficency, while fluorescent light have around 20% and LED efficiency is around 30% where as Firefl tails are 90% effective.
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