Wednesday, August 31, 2011

Weatherwatch: glow-worms

The glow-worm is named both well and badly: although it is a kind of beetle, not a worm, it certainly does glow. Or the female does, at least. Being flightless, she needs to use subterfuge to attract a mate. So as the males fly overhead, she illuminates a small patch towards the rear of her abdomen, which produces an extraordinary greenish-yellow light, via a process known as bioluminescence. This can be seen up to 50 metres away, especially on moonless nights.

Glow-worms have suffered in recent years through a combination of habitat loss and light pollution. The weather, too, has an effect: warm, muggy nights from June to August usually see more activity than cool ones.

The best places to look for them are along unlit country lanes, especially with hedgerows and grassy banks, where the females can safely hide until they emerge for their nocturnal performance. Once glow-worms have successfully mated, the female will lay her eggs. These, too, are affected by weather conditions, taking just four weeks to hatch during warm summers, but over six weeks in cool ones.

Glow-worms would have been a familiar sight to our rural ancestors, and unsurprisingly figure in our weather forecasting folklore. Some sayings seem to contradict each other, with one rhyme claiming that "When the glow-worm lights her lamp, the air is always damp", while another says that "When the glow-worm glows, dry, hot weather follows".


guardian.co.uk © Guardian News & Media Limited 2011 | Use of this content is subject to our Terms & Conditions | More Feeds

Source: http://www.guardian.co.uk/news/2011/aug/30/weatherwatch-glow-worms

Children Liberal-Conservative coalition Nepal Insects Tottenham Hotspur Savings

No comments:

Post a Comment