the complex method of development of certain insects (blister beetles, Rhipiphoridae and certain other beetles, stylopids, neuropterans, bee flies, and certain hymenoptera), in which the structure and mode of life of larvae of different instars differ sharply. In the first instar the larvae move around actively and settle in new places, but do not feed. The feeding larvae of older instars live in a specific environment (for example, in the body of the host insect in parasitism and in the food supplies of bees). Sometimes the transition from one active form to the next demands a restructuring during which the larva does not feed and is immobile (the pseudopupa, which is similar to the pupa).