Sweet-clover
Guides
Sitona cylindricollis
sweetclover weevil
Sitona cylindricollis, the sweetclover weevil, is a broad-nosed weevil in the family Curculionidae. It is a documented agricultural pest of sweet clover (Melilotus officinalis) and alfalfa/lucerne (Medicago sativa). Adults feed on above-ground foliage, causing defoliation damage that is most severe during late summer critical periods. Larvae feed on root nodules and root tissue underground. The species exhibits temperature- and light-dependent dispersal flight behavior, with peak flight activity occurring in morning hours when ambient temperatures reach threshold levels.