How long do fireflies live

Shine only to die - the fireflies' spectacular love game

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On mild summer nights in June - if you are lucky - you can watch a mysterious natural spectacle: the dance of the glow worms. During the day they lead a rather unspectacular life. But as soon as night falls, passion overcomes it, and everything revolves around one thing.

Fireflies are not worms, but beetles and are therefore also called fireflies. The worm in the name goes back to the appearance of the females of the great firefly. The big firefly is the most common type of firefly in Switzerland. Between June and July you can observe his luminous mating ritual, especially at the edges of the forest, in meadows, gardens or parks. It's nice to look at - but there is also a certain romantic tragedy behind this pairing dance.

Green love lights

When it gets dark, the females climb up blades of grass and from there send signals to the males with their glowing rear parts. The search for a partner is a race against time, because the life energy of adult animals is limited. After their transformation from larva to beetle, adult fireflies only stay alive for barely three weeks. During this time they take no more food and live, so to speak, exclusively on air and love.

In contrast to the females, the males of the great firefly are flying. As if magically attracted by the feminine glow, they let themselves fall on the chosen one from a height of around two meters. Those who shine the brightest are most successful in attracting a male.

Better than any lightbulb

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A firefly is the most efficient light body there is. It achieves a light output of almost 100 percent. Its light is created by a chemical reaction in which a substance called luciferin is put into a high-energy state. Only two percent of the energy is lost in the form of heat. For comparison: A conventional light bulb only emits 5 percent of its energy in the form of light, the rest is lost as heat. (Source: NZZ, link will open in a new window)

As soon as two have found each other, the firefly lady discreetly turns off her love light. The sexual act lasts around a quarter of an hour. After successful mating, the male dies. The life of the female is also coming to an end. It will no longer shine again, just lay eggs and then die too. His goal in life is thus fulfilled.

Please turn off the light

According to Pro Natura, fireflies are still widespread in our country, but they are also affected by the general death of insects. They increasingly have to struggle with shrinking living space and increasing light pollution. In our 24-hour society, a lot of artificial light is brought into the vital darkness for fireflies. No matter how much the females can shine - in vain. They are not found in this way by the males.

If you want to observe the magical glow of fireflies in your own garden, you need one thing above all: darkness.

The night is full of life

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Not only fireflies need darkness, but also, for example, bats that are only active at night or migratory birds that use the stars for orientation. For many insects, lamps can be deadly traps.

Placing no or only sparse artificial lighting in the garden is a first step towards a firefly-friendly garden. If you still want light in the garden at night, it is best to opt for lamps with precise light control or with screens that direct the light specifically to where it is needed. Motion detectors for light sources can be set so that the light does not come on with every movement, no matter how small. Not only fireflies, but also many other nocturnal animals will be grateful.

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Angela Wagner

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