In the early evening, females lay single eggs on geranium buds or on leaves of other plants. The larvae have several stripes but can be quite variable in overall color. Dark forms are common but red, green or light brown larvae also occur. Color differences are related, in part, to the color of the flowers on which the Insects are feeding. The caterpillars become full-grown in about a month, drop to the soil and pupate.
Adults emerge to repeat the cycle, with two generations normally produced each year.
At the end of the season, determined by declining day length and temperatures, the Insects go into a state of suspended development, which they maintain through winter. Adult tobacco budworm. In Colorado, the tobacco budworm spends the winter as a pupa. The pupal stage occurs below ground, buried 2 to 6 inches deep, and is formed within a packed earthen cell that the full-grown caterpillar produces. The insect is therefore poorly adapted to the harsh winters of Colorado.