#3
The immatures of Coleoptera are called larva(e) for they are holometabolic i.e. a complete metamorphosis (egg-larva-pupa-imago; as in Diptera and Lepidoptera). The immatures of hemimetabolic insects are called nymphs i.e. the immatures have the appearance of the adult and after each moult resemble them even more. They do not have an actual pupal stage (as in Heteroptera or Odonata). Under the shortened elytra you will discover true wings, which are absent in larval and nymphal stages. In nymphs you only have wingsheaths, becoming progressively longer after each moult.
I'm not much of a Coleoptera specialist but this picture seems to be Staphylinidae as Jorgen suggest, but the other one on agrozoo.net seems to be another family. There is more than one Coleoptera family with reduced elytra.