Which life stage of the brown-banded cockroach is recognized for banded markings?

The brown-banded cockroach is known for its distinctive markings, and these banded patterns are best observed in the adult stage of the cockroach. Adults typically display two light-colored, parallel bands that are visible across their wings and body, which is a key identifying feature of this species.

While nymphs do undergo several molts and develop as they grow, they do not exhibit the same banded markings as adults until they reach that life stage. Egg cases and pupae do not have any visible markings akin to the adult's banding, as eggs are housed in an ootheca and pupae are transitional forms that do not yet show the characteristic features of adult cockroaches. Therefore, the adult life stage is the one that exhibits these unique banded markings, making it the correct choice.