Egg - The cream colored, kidney-shaped egg is about 3 mm long and 1 mm in diameter.
Larva - The larva is cream colored and legless, with a distinct reddish-brown head capsule. It varies from 5 to 15 mm in length.
Pupa - The pupa is cream colored to reddish-black, depending upon its age, and ranges in length from 15 to 20 mm. Some adult features - legs, antennae, and beak - are apparent.
Host Plant - Corn is the preferred host of maize billbugs. However, these insects have been collected from sorghum, cattails, and many species of wild grasses, reeds, rushes, and sedges.
Damage - The maize billbug is one of two billbug species which annually damage corn in the Coastal Plain of North Carolina. Although it causes similar damage, the other species, S. callosus, is apparently more abundant and difficult to control in both North and South Carolina. The adult billbug pierces corn seedling stalks with its beak, damaging the tender inner tissue. This injury often causes stunting or death of seedlings. Stunted plants usually produce excessive suckering and become deformed and nonproductive. Plants which survive attack are marked by rows of holes across the blades. In addition to adult attack, maturing larvae tunnel in the basal area of the stalk. Extensive damage is generally restricted to non-rotated corn fields or areas adjacent to the previous year's corn.
Life History - During April and May, the overwintering adults, which rarely fly, emerge from litter in the field, ditches or hedgerows. After feeding and mating, females lay about 200 eggs. Eggs are deposited in holes chewed out by females in the basal area of host plants. The tiny, legless larvae hatch from the eggs in 4 to 15 days and feed for several weeks in and around the taproot. Although several larvae have been observed in the taproot area of a single corn plant, there is usually only one larva per infested stalk. Larval development is complete in 40 to 50 days, and pupation occurs in cells in or near the excavated taproot. After a 2-week pupal stage in August or September, the adults emerge from pupal skins and either remain within pupal cells or exit and feed before entering hibernation. Only one complete generation occurs each year.