The morphological ontogeny of Melanozetes interruptus Willmann, 1953 is redescribed and illustrated. The juveniles of this species are brown with dark-brown sclerites. In juveniles humeral organ and humeral macrosclerite are present, seta c₁ is inserted on humeral macrosclerite, and setae c₂ and c₃ are inserted on microsclerites. In the larva, the gastronotal shield has seven pairs of setae (d-, l-series and h₁), in the nymphs it has nine pairs (d-, l-, h-series), whereas all setae of p-series are inserted on microsclerites, which is unique in Melanozetes Hull, 1916. In most nymphs of this genus seta p₁ is inserted on gastronotal shield. In the juveniles and adult the legs are stocky, all femora are flattened, and femora I and II have a large ventral carina. Solenidion ω₂ on tarsus I is located anterior to solenidion ω₁ and is longer than ω₁. In this species tarsal setae a are clearly longer than seta s.