Bright lights and progress put glow-worms in the dark

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The Independent Online

Glow-worms glimmering in the night have for centuries been a source of fascination to poets, children and lovers.

Glow-worms glimmering in the night have for centuries been a source of fascination to poets, children and lovers.

But a study now suggests that the population may be dwindling or that the attraction of walking down country lanes after dark has dwindled and we simply no longer notice the presence of the insects.

Changes in human lifestyle mean that even people living near to colonies of the creatures are no longer aware of them, says John Tyler, co-author of the paper "Are Glow-worms Disappearing?" in the current issue of British Wildlife.

"Children used to collect them in match boxes but now they don't play in the countryside as they did in former decades," he says. "Also, since the advent of cars, adults walk along country lanes after dark less often."

Glow-worms have long cast their spell over humans. Shakespeare mentioned them at the end of the Ghost's speech in Act 1 of Hamlet: "The glow-worm shows the matin to be near/And 'gins to pale his uneffectual fire."

In 1648, the poet Robert Herrick used a glow-worm as an allusion in a romantic epistolatory poem The Night-Piece, to Julia. He wrote: "Her eyes the glow-worm lend thee/The shooting stars attend thee."

Fifty years ago, enterprising campers were known to collect them in jam jars to provide enough light to enable them to read in their tents after darkness had fallen.

But the study says that the glow-worm population is likely to be reduced. "Many habitats which once supported glow-worms have been completely destroyed through road-building, urban development and conversion to arable fields, improved pasture and forestry plantations," the study says.

"Since the 1940s, 97 per cent of lowland flower-rich grassland, 80 per cent of chalk and limestone grassland and 67 per cent of hedge rows have been destroyed. The destruction of these important glow-worm habitats must have had a severe impact on populations."

But increases in man-made lighting could further have affected numbers, particularly of males, which follow the glow of the female. "Male glow-worms are also attracted to house lights, often in large numbers. As well as actively attracting males, the glare of artificial lights may also reduce the visibility of the female's glow."