In biology, the imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis (biology), or after emergence from the pupae where the metamorphosis is complete. As this is the only stage during which the insect is sexually mature and, if it is a winged species, has functional wings, the imago is often referred to as the adult stage.
The Latin plural of imago is imagines, and this is the term generally used by entomologists - however, imagos is also acceptable.
The stage of subimago exists in the Ephemeroptera (mayflies). Insects at this stage have functional wings but are not yet sexually mature.