The egg, larval, and pupal stages are aquatic. Longer days may prompt pupae to develop early, while shorter days result in pupal diapause. Most fleas are distributed in the egg, larval, or pupal stages. Insects emerge (eclose) from pupae by splitting the pupal case. Flea larvae metamorphose through four stages before spinning a cocoon and entering the pupal stage. Thrips can survive the winter as adults or through egg or pupal diapause. It has four life stages; egg, larval, pupal, and adult. In the temperate regions, the winters are passed in a pupal diapause stage. The caterpillar molts five times before entering the pupal stage. Mature larvae drop from the host and complete the pupal stage in soil. They moult at regular intervals, usually four to six times before entering the pupal stage. At the molt that marks the beginning of the pupal stadium stage, they become functional. At the end of the pupal stage, tsetse emerge as adult flies. Weevils in the pupal stage have snouts like the adults. It infects the subcutaneous tissues and propagates by spores formed during the pupal stage.