Paedogenetic: reproducing in the sexually immature or larval stage.
Paedogenesis: reproduction in the sexually immature or larval stage.
Ultimate: last or final: that larval stage just before pupation.
The empty case at a shows the last stage of the larval life.
The ant-lion was the larval form the lace-wing fly, of course.
In the skin of a larval salamander they are ...