Head: Black, shiny. Whiskers (palpi) reddish-yellow.
Antenna: Yellowish-brown, reaching to end of thorax. Sometimes segment 1 slightly lighter.
Thorax (Pronotum): Black, shiny, squarish with rounded corners. Lower margin depressed and rough (punctured). Faint longitudinal indented line down middle of thorax. Sides only slightly rounded, rim or shelf narrow at base, widening at lower margin.
Wings (Elytra): Black, not as shiny as head and thorax; wings as wide as thorax. About 8 or 9 longitudinal indented lines down wings. Tips bluntly rounded, abdomen slightly protruding past wings.
Legs: Reddish to yellowish-brown. Thighs (femora) have dark tips. Shins (tibia) with rows of dark hair. Male has front and mid feet with pads on underside.
Abdomen: Underside dark.
Similar Species: Seedcorn Beetle Stenolophus ochropezus is almost identical, except for size. Antenna segments 1 and 2 light yellow, rest of antenna dark. Only 5 to 8 mm long.
Size: 13 to 16 mm.
Habitat: Field edges and meadows with long grasses, especially switchgrass; alvars.
Food: Grass and weed seeds and small insects, including moth eggs and larvae.
Flight Time: Late July to September.
Life Cycle: Adults nocturnal, hiding in debris during the day. Larvae live in tunnels in the ground, and pack them with seeds. Mating in late summer. Over-winters in all life stages. Adults can live up to 2 years. Attracted to lights.
Comments: Essex County – Point Pelee National Park. Widespread in Ontario, common.
For information on synonyms, references and type specimens see next page