substage of immediately preceded by developmental stage early third instar larval stage wandering third instar larval stage third instar - uncleared gut stage FlyBase_development_CV FBdv:00007019 Temporal ordering number - 462. This is commonly assayed by adding 0.5% bromophenol blue to the food and looking for wandering third instar larvae with the same color guts (dark blue) as feeding larvae (Andres and Thummel, 1994). Larvae at this stage are in chromosomal puff stage 1 (Andres and Thummel, 1994). The substage of the wandering third instar larval stage, prior to the beginning of clearance of the gut.