There are two very similar species of Sphaeroderma in Britain and both feed on Thistles. Both are red coloured and generally round-bodied. S. testaceum is slightly larger but there is much overlap.

S. testaceum: Body less strongly rounded, slightly but distinctly elongate, the pronotum less strongly narrowed from the base and more strongly punctured, especially towards the basal margin. 2.5-4.2 mm.

S. rubidum: Body strongly rounded, often almost circular, pronotum very strongly narrowed from the base and very finely punctured. 2.3-3.5 mm.

Found wherever the foodplants, various species of Thistle and occasionally Common Knapweed are abundant, including roadsides, wasteland, woodland etc.

May/June to September.

Pupation occurs in the spring and new generation adults are seen from May. Both larvae and adults feed on leaves.

Common and widespread in England and Wales, less so further north.

Fairly frequent in Leicestershire and Rutland.