IMAGO

In biology, the 'imago' is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, 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.