LIFE CYCLE The Tenebrio molitor beetle has 4 life cycle stages. The time spent in the egg, larva and pupa can vary widely depending to diet humidity and temperature. Egg- The egg stage lasts between 4 and 20 days. If the eggs are kept in the fridge or at temperatures below 10c the eggs will remain dormant and will not develop until temperatures rise. Larva- 4 weeks or longer. The larva stage is the longest stage of the beetles life cycle. The time spent in this stage is mainly dependent on diet and temperature. The larva are known as mealworms. Pupa- Pupa look like white aliens and are immobile while they complete metamorphous. The pupa can wriggle. It can take as little as 6 days for pupa to hatch into beetles depending on temperature and the diet they ate in the larva stage. Pupa should be removed from larva and beetles to avoid being eaten. Beetle- The beetle stage can last up to 8 weeks and not much longer. The beetles sole concern is eating and mating. They are most active at night. Each female beetle can lay several 100 eggs in over the 8 weeks they live.