Common glow-worm
Lampyris noctiluca
Also called: Common European glow-worm
At a glance
- Flash
- No flash — the flightless female emits a steady green glow to attract flying males
- Habitat
- Grassland, hedgerows and woodland edges, often on chalky soils
- Range
- Across Europe and into Central Asia
- Season
- Midsummer nights (roughly June–July)
- Size
- Female up to ~25 mm; the flying male is smaller
- When active
- Late evening through the middle of the night
Overview
In this species it is the female that glows. She is larviform and wingless, and on a midsummer night she climbs a grass stem and raises the tip of her abdomen, shining a steady green light upward to call in the flying males. It is a continuous lantern, not a flash — one of the quiet marvels of a European summer.
The males fly and have large eyes tuned to find that single green point in the dark. Neither sex feeds as an adult; all their energy went into the year or two the larvae spent hunting snails in the undergrowth. A steady glow low in the grass, held for many minutes, is almost certainly this species.
How to identify
A steady, non-blinking green light low in the grass on a warm summer night is the female glow-worm. If it isn't blinking, it's very likely Lampyris.
Conservation
Declining across much of Europe. Light pollution is a direct threat — artificial light drowns out the female's glow so males can't find her. Volunteer glow-worm surveys track the trend.
Sources & further reading
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