Paul writes: It’s a pity that the appearance of this beetle isn’t quite as dramatic as its common name suggests. The name comes from the beetle’s defence mechanism, which is that when threatened the beetle releases a bright red fluid from its mouth.
It’s a slow moving domed beetle, up to 20mm long, coloured black or bluish black depending on the light. Also, the feet appear to have a creamy white edge or underside. The beetles usually start emerging in April, but adults can live up to 14 months, so they can turn up throughout the year. I usually see them in grassy habitats lumbering slowly through the undergrowth or across a path, like these two were. Males are generally smaller than females, which shows up in the picture. They are flightless, so once seen are quite easy to follow. Being flightless also gives another good identification feature. The wing cases (or elytra) which normally open when a beetle takes flight, can be seen to be fused together along the back.
It is quite widespread in England & Wales, maybe less so in Scotland, and as usual with most insects, is commoner the further south you are. I found this one last year at Nosterfield Nature Reserve in North Yorkshire. This was on 9 April, which is the earliest I have seen it. I don’t think I’ll beat that this year but hopefully it won’t be long after before I see one.