The term 'developmental insect stage' refers to the life cycle of an insect, which includes four stages: egg, LARVA, pupa, and adult. The LARVA stage is the second stage in the life cycle of an insect, and is characterized by a worm-like body with no wings or legs. During this stage, the insect undergoes a process of metamorphosis, where it changes from its larval form into its adult form. This process is essential for the insect's survival and development.