A body form that is worm-like, lacks a distinct head, and is legless. This term often is used to describe fly (Diptera) larvae, but also applies to newly hatched grasshoppers. Such newly hatched grasshoppers, called vermiform larvae, are enclosed in a membrane, so the legs are not functional. Vermiform larvae wiggle from the below-ground egg pod to the soil surface, where they free themselves from the membrane and possess functional appendages. Only after escaping from the membrane is the young hopper considered to be a first instar.