Mealworms go through four stages in their life cycle: egg, larva, pupa, and adult:
Egg
Female mealworms lay eggs on any surface, such as the bottom of a container or egg carton. Eggs hatch after 4–19 days.
Larva
Mealworms feed on dead insects and vegetation, and molt through 9–20 larval stages. Larvae can grow to be 2.5 cm or more in length.
Pupa
When temperatures drop, mealworms transform into pupae to hibernate. Pupae are C-shaped, stout, and yellowish-white in color. They darken as they get closer to adulthood. The pupal stage lasts 7–9 days at 25°C and up to 20 days at lower temperatures.
Adult
After emerging from the pupa, the adult mealworm beetle is white at first, then turns brown, and eventually almost black. Adult mealworms live for 2–3 months.
The length of a mealworm’s life cycle can vary from four months to a year, depending on the temperature and food availability. Mealworms are considered pests because they eat grains and get all the water they need from their food.
