Monster larva

Monster larva

Observation - Monster larva - UK and Ireland. Description: 12mm across, in the middle of my compost bin among half-rotted material half a metre above ground le

12mm across, in the middle of my compost bin among half-rotted material half a metre above ground level. Warm and dry to touch - I kept it warm in a plant pot full of compost while I finished digging out, then put it back.
Edit: the following June I found a fresh glossy adult female a few feet away. Possibly the same insect.