In this paper, the food of nineteen species of Cychrini is given, for three genera: Cychrus, Scaphinotus and Sphaeroderus. The beetles of this tribe seem to be nearly exclusively carnivorous, feeding principally on snails and slugs, exceptionally on insects and vegetable matter. The head is narrow and prolonged; the mandibles are elongate and prominent, with two acute median teeth in outer half, apparently well adapted for entering the opening of a snail shell. The beetles may be useful in keeping down harmful molluscs.
The purpose of this study was to compile a list of data on the food of some Cychrini, from the literature and observations in the field. Almost all species live in forest country and appear to be nocturnal. Cychrus caraboides Linne, Cychrus dufouri Chaudoir, Scaphinotus bilobus Say and Sphaeroderus lecontei Dejean have been noted searching for food on rainy days.
"Notes on the Food of Cychrini (Coleoptera: Carabidae),"
The Great Lakes Entomologist, vol 5
Available at: https://scholar.valpo.edu/tgle/vol5/iss3/3