From Hatchling to Pre-Pupal
Determine BSF larvae stage through the size of head capsules (e.g., mouth part) and observation of a molt (e.g., shedding skins) between feeding-larvae and pre-pupal.
First instar: the larvae hatch from the eggs, also called neonate. The first instar becomes second instar larvae in less than 24 hours.
Second instar stays for 2 days. Within the 2 days, BSF larvae body mass and head capsule did not change so much.
From the second instar, a faster development occurs as the 3rd and 4th instar last only 1 day each.
Fifth instar lasts for 2 days (e.g., a window time for tipping or re-feeding).
The sixth instar spends 8 days actively feeding larvae before molting (i.e., see larval shedding the old skin) into the seventh instar.
Seventh instar (pre-pupal) has reduced mouthparts and enters non-feeding stage.