Each female lays about 275 eggs, which hatch into larvae in 4 to 14 days. Eggs are laid singly or in clusters during the spring over a period of 22 to 137 days. Larvae may spend up to two years in this stage depending on the environment. Individual larvae may wander far from the food source to pupate, making it difficult for homeowners to locate the source of infestation. Most larvae mature by fall, overwinter and pupate in the spring, with the pupal stage lasting 7 to 24 days.
Adults emerge in the spring and early summer, living two to three months.
Control Measures Prevention Mealworms are not always considered pests since some people raise them for fish and animal food. Use good night-light discipline to reduce beetle attraction and infestation indoors. Sanitation is the simplest means of controlling mealworms. Moist, dark, undisturbed areas containing damp grain or milled cereals should be eliminated. Poultry litter dumped into piles outdoors can result in mealworm migrations indoors.