They leave nothing to burn

"They radiate a wonderful, imitating shining luster, which seems to compete with a lantern and the moon with regard to brightness," writes Alfred Brehm in his animal lexicon.
So much poetry for what? An insect. A crab-like black-brown beetle, in front of which, in daylight, little girls would probably run away screaming. The beetle is often referred to as a worm, but worms do not sound much poetic than beetles. Nevertheless, the firefly has made it a protagonist in a poem by Friedrich Gottlob Klopstock.
Not only does it deserve attention from poets, but it also creates something that many of the engineers, especially Thomas Edison, should envy: it shines.
Although it is not the brightest (a candle is 1000 times brighter), but the firefly is unique efficient. While each bulb emits only five percent of its energy in the form of light and the rest as heat, it is exactly the opposite of the Lampyridae: 95 percent of the generated energy is emitted in the form of light - an efficiency that has not yet been an artificially produced light source has achieved.


At all: Lights! Not simply fluorescence, like jellyfish, or phosphorescence, like the gluten starter above the child's bed. But: bioluminescence. This means that in order for your own lamp to go, they need not be charged or irradiated by the sun. Something that no other animal living on land can do as the firefly Bioluminescence is the ability of living beings to generate light in a chemical reaction in their cells. The enzyme luciferase converts the substance luciferin. Light is formed as a by-product of this reaction. This reaction can turn the beetles on and off, so they do not light continuously.

The cells of the fireflies thus generate their own light. This distinguishes the bioluminescent insects from other animals, which have only the art of phosphorescence and fluorescence. The latter only illuminate when they have previously been irradiated with light.

But not only the grown beetles glow but the eggs and larvae are capable of bioluminescence.
The lanterns, which are called lanterns, are always close to the surface, but can be distributed over the entire body. Inside, the lanterns are shielded with salt crystal layers, which reflect the light outward. This reflective layer makes fireflies so efficient light sources.

But why does it matter? Why does the insect flash and glow? But surely not so that we can write poems about them? For fireflies, their body-borne lamp is vital: sex, eating, non-eating - for all this, fireflies use their rays.

Tropical firefly larvae shine, for example, to signal toads that they are not at all palatable, or to lure prey into their nets, costing them less energy than any other strategy they might gain.

It is also indispensable, as a firefly, to be in the right light for the search for partners and for reproduction. Firefly beetles do not just light up anyhow, but according to a species-specific pattern, where females and males recognize themselves. With signal length and rhythm, the beetles munched their courtship messages through the forest and meadow at night.

However, depending on the species and habitat, fireflies flirt differently: American beetle males (Photinus pyralis) flash vigorously and wait for the female to answer. In tropical species, all beetles synchronize their lanterns, so that whole forest edges flash at the same rate.

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Other firefly men even risk their lives in love. The females of the tropical genus Photuris mimic the signals of the Photinus-Siblings and thus lure Photinus-males with joyous expectation on a female willing to mate. Instead of getting sex, they are eaten by the photuris-women.

Fireflies are at all very intrepid contemporaries. While we leave human snails to the stereotype according to the French, there is nothing more tasty than a slime-slug snail for domestic firefly larvae, which they take out with a single poison bite.

The small beetles use every night as if it their last. They radiate out of themselves with full force and are also still romantic: for grown beetles do not eat anything. They live by air and love. And their fat reserves. Until the light goes off.