Glow worms at Priston

Glow worms are one of those creatures that most people have heard about but few have seen. However, if you know where to look and when, it is possible to find glow worms in the countryside surrounding Bath. When discovered, glow worms should be left undisturbed in their natural habitat.
 
Glow worms belong to a family of beetles called the Lampyridae. There are two species of glow worm in Britain, one of which is quite rare. The photos below show the common species Lampyris noctiluca in the lanes around Priston Village near Bath. The pictures were taken by a party of people who were surprised to count more than twenty glow worms on one night in August 2007.
 


 
A glow worm emits it’s pale green light

 
The wingless female glow worm is worm-like in appearance as the name suggests, whereas the male is more recognisable as a beetle. The female produces a glow in the last three segments of her body to attract males. The segments contain a layer of a substance called luciferin, as well as a layer of reflective crystals. By controlling the flow of oxygen to the luciferin the female is able to turn her glow on and off. The chemical reaction is very efficient, as nearly all of the energy is converted into light.
 


 
The female glow worm is longer than the male

 
Adult glow worms only live for about two weeks. Having mated, the females lay their eggs and die shortly afterwards. The larvae hatch a few weeks later and remain as larvae for one or two years, before turning into adults. The larvae feed on small slugs and snails, grasping them with their jaws and injecting them with a fluid which liquefies them ready to be consumed. Glow worms are typically found in hedgebanks and grassy areas.
 
The photos in this article are reproduced by kind permission of Mr Richard Bottle, who writes a community website for Priston at: www.priston.org.uk.