Two lamp-trimmers at Gwenallt Deep disagree about the beetle, and have for years. One holds that the glands above its eyes burn because it eats coal dust. The other holds that it burns because it eats the rot in the timbering. The naturalist has watched it chew both and cannot settle the matter, though the timber, at least, comes away with a pale, scraped look that coal does not.
Kerra Maddox trims lamps for the lower galleries, and her working day is built around the creature without ever requiring her to see it. She rises in the dark, fills forty-one oil reservoirs from a drum, and counts glow-glands instead of wicks. A live gland, orange-yellow and steady, is worth about six hours of lamp. She collects them from the carcasses of beetles that die of old age in the sump passages, never from the living, and sets them in glass jars along the haulage way. By midday the jars have dimmed and she swaps them for fresh ones. In the afternoon she walks the Uskerry gallery with a pole and a rag, wiping the soot off the jars. The beetle itself appears twice in her shift. Once at the ore chute, a body the length of a mule's head, dark red-brown with a mossy sheen on the wing cases, drinking from a seep. Once again near the end, crossing the track at a walk, its twin lamps throwing two moving circles on the wall. She stops her pole and waits until it is past.
The rule at Gwenallt is that no one strikes a flint within thirty paces of a feeding beetle. The glands flare when the creature is startled, and a flare will light the firedamp that gathers in the low drifts. Miners wet their palms and hold them over their lamps instead, and the beetle settles. The practical sign of one nearby is a smell of warm tin and a thin ash that dusts the floor behind it, which the miners call its wake and follow to find sound air.
Things have changed between my visits. On the first, the beetles kept to the sump passages. On the most recent, two had moved up to the Uskerry gallery and were feeding at the chute, and the miners had stopped being troubled by it. Maddox says the colony grew when the old pumps were shut down and the water pooled, which fed the rot. I have no means of checking this, and no one has counted them. There is one exception to all of it. In the dead end past Uskerry, the beetles do not glow at all. They lie against the rock with their glands dark and their legs drawn in, and a lamp held near does nothing to them. Maddox will not go there, and says the jars she once left there never held a light again.
- Classification
- Giant luminous beetle
- Habitat
- Deep mines, wet caverns, sump passages
- Danger
- Low
- Size
- the length of a mule's head
- Activity
- Always
- Realm
- Underground workings
- Binomial
- Lampyrinus ignivorax
- Diet
- Rotting timber, coal dust, seep water
- Temperament
- Placid unless startled