I decided to a bit of work in the garden yesterday afternoon. As I was clearing away some of the dead wood from some old tree stumps round the back of my shed, I came across these wee beasties. They were massive. Unfortunately they were a tad camera-shy, but before they curled up, they were around 50mm long and 8-10mm in diameter…
They certainly seem able to chew some quite impressive holes in these rotting tree stumps – some 10mm-12mm in diameter.
As you can see from This close-up, they seem to have quite powerful jaws too.
Thoughts of that old Dr Who series “the Green Death” flashed across my mind when I first stumbled upon them yesterday. Though TBH I was more concerned that they were hostile guests from another country rather than from another planet. They clearly like wood. Unfortunately the rotting tree stumps they currently inhabit are a few centimetres from my new wooden shed and less than a metre from a row of young Portuguese laurels we planted to replace the unsafe trees we had to fell. However further reading suggests they like decomposing wood and are unlikely to eat my shed. Apparently tanalised timber does not taste nice to a wood-boring grub. 🙂
After asking around a few folks with far greater knowledge of the things than I have, I concluded they are first year stag-beetle larvae. Apparently they can grow to over 110mm long. The trees were felled five years ago. One of the stumps has already rotted and disappeared. In fact it collapsed when I stepped on it around this time last year. Unfortunately I already broke off a chunk from this stump too, before I learned of the existence of its inhabitants. But there is still a sizeable chunk left, which I will leave alone at least until after they have pupated.
However I think these creatures face another danger. The space behind the shed is part of our “hedgehog highway”. I didn’t actually weigh them, but guestimating from their size (πr²l) I reckon they are currently around 4 cubic centimetres – meaning they probably weigh around 4 grams. Which means that unless they stay well hidden, I fear many may become tasty nutritious snacks for passing hedgehogs. 🙁
Quite an interesting “lifecycle diagram” I came across…
Fortunately, my visitors only seem interested in these old tree stumps and are probably doing me a favour. So I carefully put them back where I found them and left them to their business. No large wood-boring grubs were harmed in the production of these photos!