Which insects have 1/2 inch adults with two pairs of wings that are often reduced in size?

The correct choice, earwigs, can be identified by their distinct characteristics. Adult earwigs typically measure around 1/2 inch in length and possess two pairs of wings; however, in many species, the second pair of wings is reduced and not fully functional. This unique feature sets them apart from other insects listed in the choices.

Earwigs are recognizable not only by their wing structure but also by their pincers or forceps-like cerci at the rear of their bodies, which is a critical identifying feature that distinguishes them. They are primarily nocturnal creatures and often hide during the day, making them less visible than other insects.

In contrast, cockroaches also have wings but are generally larger and their wings are fully developed. Silverfish do not possess wings at all, and although fleas have wings in some species, they are primarily known for being wingless parasites that jump rather than fly. Understanding these specific traits helps clarify why earwigs are the correct answer to the question regarding insects with reduced wing size.