Life cycle and appearance of the corn earworm

The eggs of corn earworm are a milky-white colour, which turn dark grey before hatching, and have a ribbed spherical shape. The larvae hatch after around four days. The corn earworm caterpillars go through six larval instars, over a total period of two to three weeks, developing a greyish colour and a black cephalic capsule in the first stage, but later adopting a variety of colours such as green, brown, pink, and yellow. Other features are its size in the final instar (approximately 35 mm) and its longitudinal stripes on the body. When the larva has fully developed, it stops feeding and descends onto the ground to bury itself around 10-12 cm deep. This prepupal stage takes one to two days. It then pupates for ten to fourteen days, or three to five months in areas with very cold winters. The pupae measure around 18 mm and have a slightly shiny brown colour. The adults have a brown-coloured body, with a wingspan of 35 to 40 mm and a dark stripe on the side edge of the forewings and hindwings; they live for around two and a half weeks.