Abstract: The structure of respiratory system during the 1st-2nd instars and the 3rd-6th instars of Luciola substriata larva was observed using micro-dissection, transmission electron microscope (TEM) and scanning electron microscope (SEM). The results indicated that the 1st-2nd instar larva had trachea without air sacs, while the 3rd-6th instar larva had trachea and air sacs in the respiratory system. The structure of the posterior spiracles of the 1st-2nd instar larva was the same as that of the 3rd-6th instar larva. Observations by TEM suggest that the hairs on the culticle are tracheal gills.  

Key words: Luciola substriata, larva, respiratory system, trachea, tracheal gills, air sacs