My son and I found this caterpillar on our allotment last year and so far have been unable to identify it. It was found on bare soil, and its head and body segments had a hard covering. As you can see it had hard spines rather than hairs along the sides of it body. We have nicknamed it the "war caterpillar" for its formidable appearance!
What a great find. This is not a caterpillar but the larva of a beetle - admittedly looking a lot like some caterpillars. The beetle is Drillus flavescens (common name = Drillid beetle) and the larvae are snail eaters, which is just what you want to hear about insects living on your allotment. In the UK it is a species with patchy and somewhat local distribution and most common in chalky areas - I have only found them occasionally in the Chilterns for example.
Here is a little more info with image of the adult beetle on the appropriately named "wonders at our feet" website - which it truley is.
Many thanks for your help - thats very interesting and my son will be fascinated, he's a very keen young entomologist! We live in Dorchester, dorset, which matches your description as it is a very chalky area. Im also sure ive seen the adult beetle on the site as well.
Gordon and Max.
I'm quite fascinated by this species now - it has one of the most remarkable cases of sexual dimorphism in the animal kingdom. The male emerges from its pupa as a beetle, the female emerges having hardly changed from its larval form at all!
I think I found a female emerging from its pupa a couple of weeks ago. Sorry about the picture quality but I only had my phone on me.
I then moved it to a plank for a better shot, then set it free in some leaf litter.