Fifth-instar larvae increase in weight 2000 times from first instars. Emerald ash borer has four larval instars. Larvae go through two instars before pupation. The postembryonic development consists of four larval stages (instars) and one pupa. Larvae progress through four distinct growth stages (instars). All beetle larvae go through several instars, which are the developmental stages between each moult. Within the puparial shell, tsetse complete the last two larval instars and the pupal stage. When possible, larva will cannibalize the larva of smaller instars. There are typically five larval instars (developmental stages), each lasting approximately one week. Lice have the fewest life stages of any insect (egg, 3 larval instars, and adult). Larvae feed inside the tents until the late instars. After five to six instars, the nymphs will molt into adults. Larvae have five instars or sub-stages of development. Oribatid mites have six active instars&colon; prelarva, larva, three nymphal instars and the adult. Their locomotion slows when they moult into their second and subsequent instars.