Posted: Wednesday 7 May 2014
by Richard Jones
A madly animated shining bullet takes off at top speed across the flagstone, but this is just another ordinary day for the gardener - it's a ground beetle.
A madly animated shining bullet takes off at top speed across the flagstone, but this is just another ordinary day for the gardener - it’s a ground beetle.
Perhaps the most beetle-shaped of beetles, this large group of sleek, relatively long-legged and highly mobile insects is fascinating. Some of the tiny (2-3mm) types dash around on the bare mud of pond and stream sides, while others hurtle across the patio in the bright sunshine. Some of the handsome larger (to 30mm), more sedate species are nocturnal, hiding away during the day under logs and large stones.
It’s easy to pick out some interesting facts about them. They all have sharp jaws to hunt other small invertebrates. They have large eyes, all the better to find their prey. Perhaps my favourite abstruse fact about them is a bulbous structure on each of their hind legs. This muscle-filled segment, the trochanter, gives them the ability to lever their body upwards with greater-than-average beetle power, when they have burrowed hard into the root thatch, allowing them to wedge-push their way even deeper into the soil/herbage interface.
And so it was with this one, happily wedging itself under the Alchemilla mollis down the edge of the old concrete front path that I was busy replacing last week. Leistus spinibarbis doesn’t have an English name (at least not one I’d deign to use, being a purist, you know). I almost find this slightly surprising, because it's a common and familiar insect in gardens, and a close look at the head shows that it has strangely flanged jaws, which stick out like Edwardian whiskered sideburns. Quite what the purpose of these broad mandibular edges is, I haven't quite discovered. I’ll add a postscript when I do.
Anyway, the most delightful thing about it is its colour. Racing ground-beetle metallic blue? It’s an obvious choice for car manufacturers. I’d buy one.