The Glow Worm
The Glow Worm (Lampyris noctiluca)  is without doubt, one of our most fascinating of insects, potentially having the charm to encourage an early interest in our natural history. Its glow is the basis of fairy tales and folk lore over countless centuries, but the Glow Worm is in national decline.

Nottinghamshire is fortunate in having one of the largest colonies in the UK within the heart of Sherwood Forest. We have studied this colony since 2008, but continuously since 2009. Much has been learned about them, but there is much more to learn from a beetle that we originally thought had already offered its secrets to the world of science.

The Glow Worm is a difficult species to see through having nocturnal habits anyway, but we are finding evidence that it is difficult to find through being in decline.

Glow Worm life-cycle

Mated females begin to lay eggs shortly after mating is completed. A female we caught with a male one evening in 2008, had begun laying by the end of the night. Eggs were laid just into the soil substrate, usually into available cracks and crevices and hatching took place after three weeks. The larva is carnivorous, feeding on a diet of small snails and slugs. Maturity can take around two years to complete, but is often shortened when larvae are kept in captivity, where the temperature is slightly warmer and the food supply is good.

The adult female is unable to fly, but the male is fully-winged and more typically beetle like. Both adults do not eat, but they can absorb water. Glow Worms traditionaslly prefer grassy habitats, but disused railway lines, open forest rides and roadside verges on well drained soils are all ideal sites to look for them.

The light from glow worms is a form of bioluminescence and caused when luciferin molecules are oxydised to produce oxyluciferin, with the enzyme luciferase acting as a catalyst in the reaction (Ref: UK Glow Worm Survey website) Subtle differences are evident in the shapes of the glowing plates of four different females, photographed at Clipstone Old Quarter during June and July 2008.

Nottinghamshire and UK status

It is safe to claim that we know little more about the current status of the Glow Worm in Nottinghamshire now, than Victorian naturalists did over 100 years ago. The one fact we should actually know, is whether or not the Glow Worm has actually declined in the county. Certainly there is a lack of modern records from many of its known sites, but is this through genuine decline, or just a lack of recording?

The problem is that few people, other than ourselves and a handful of others, are actively going out and recording Glow Worms in Nottinghamshire. Anti-social behaviour and the fear of violence, must play a considerable part in stopping people venturing out after dark in certain areas, which can be quite understood as personal safety has to come first, so public reporting is always going to be unlikely.

  The Nottinghamshire county recorder is still of the opinion that Glow Worms are quite widespread throughout the county, yet the distribution maps would claim otherwise and the lack of historical records or reported sites, would suggest that Glow Worms have never actually been widespread. Certainly, there must be an element of secrecy regarding some colonies in Nottinghamshire and while we have been informed of at least one healthy colony on private land in the Dukeries, there must be others out there.

If other people are indeed keeping an eye on their local colony, then they are not letting on. This is a shame really, because nationally collated data suggests that the Glow Worm has actually decreased in the past 100 years. This may well be the case, but has our most charming beetle declined in Nottinghamshire? The answer is probably yes, but it is proving that it has declined effectively through a lack of surveying, that seems to be the main problem.

The Nottinghamshire Glow Worm Survey 2015

In 2012, we started a county wide survey for Glow Worms. We had hoped to get most of the sites surveyed during the Summer of 2012, but the challenge proved too great to be undertaken in just a single year. If you would like to help and join in the survey next year, please contact us by clicking the banner below for more information and the latest survey results from 2013 and 2014. Or if you know of any Nottinghamshire sites, simply send any records you already have directly to us.

Historical records of the Glow Worm in Nottinghamshire