The ambush hunter. Common Bank Ground Beetle, Elaphrus riparius photographed in Belgium. This medium sized species of ground beetle is found on wet and relatively open banks of rivers and ponds, where he hunts on springtails. At first sight the species looks dull greenish brown and is barely visible against the brown colours of the bank of a pond, which is often locally overgrown with greenish algae. When having a closer look it is a precious green jewel with purple blue dots. Nature Threads