Nature Notebook

Glowing, glowing, gone?

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Worcestershire Wildlife Trust @WorcsWT t worcestershirewildlifetrust G worcswildlifetrust.co.uk w

The light of a glowing beetle was once much more common across Worcestershire but they’re still hanging on...

On a balmy evening last summer I left the door open later than usual and in flew a male glow worm. I was so excited! It’s hard work to try and find glow worms these days so to have one in my house was incredible. What’s even more exciting is that it probably means that there’s a glow worm population not far away – the males are reluctant fliers so, theoretically, he’d come from relatively close by.

Despite their name, glow worms are actually beetles. Only the females glow brightly; males and juveniles have the ability to produce a weaker glow but rarely do. The yellow-green glow is called bioluminescence – a chemical reaction – in a number of segments at the base of the abdomen. Flightless females clamber up tall grass stems, lift the bottom of their abdomen into the air and glow to attract a mate…perhaps it was the glow of the light in my house that confused the male that arrived last year. As well as pesticide use and mismanagement of the places that they live, light pollution could be one reason for their decline – how could a female glow worm possibly compete with street or security lighting?

Adult glow worms live for just a few weeks and put all their energy into finding a mate and producing the next generation – they don’t even eat. This is left to the larvae who can take two to three years before fully maturing. During this time they are voracious snail hunters with toxic bites that paralyse their prey and dissolve its soft body parts. Glow worm larvae have occasionally been spotted riding on the snail’s shell, waiting for the process to complete before drinking the gloopy remains!

Glow worms are widespread across Worcestershire but we think populations are decreasing – they’re certainly much harder to spot these days and in fewer numbers too. Could this be down to the fact that the females stop glowing when they’ve mated and we’re just not seeing them at the right time? So, here’s your challenge! Gardens, bases of hedgerows, railway embankments, canal towpaths, woodland rides – places where the grass is left long until late summer – are all places that you might spot a glowing beetle. To spot a glowing female you’ll need to be out when dusk has fallen and darkness is on its way (they burrow underground during daylight hours to avoid predators). Let your eyes adjust to the light levels and look carefully because they can be easy to miss.

I’ll definitely be spending time this June looking for my local glow worm colony and I’ll be doing this as part of 30 Days Wild, the annual celebration of nature where we invite you to sign up for a free pack of inspiration to help you reconnect with nature each and every day of June. Take a look at www.worcswildlifetrust.co.uk/30DaysWild for more information. n