Biology · Structural Organisation in Animals · NEET
The hindwings (second pair, from the metathorax) are used for flight. They are thin, transparent and membranous, so they can flap and generate lift. The forewings (tegmina) are hard and mainly act as a protective cover for the delicate hindwings; they do not do the real flying.
Tegmina (forewings) are on the mesothorax (the middle thoracic segment). The hindwings are on the metathorax (the last thoracic segment). NEET loves to swap these two, so fix it as: Meso = Tegmina, Meta = membranous hindwings.
Tegmina are the first pair: dark brown, thick, tough, opaque and leathery, arising from the mesothorax, and they protect. Hindwings are the second pair: pale, thin, transparent and membranous, arising from the metathorax, and they are used to fly. Both are wings, but only the hindwings do flight.
Tegmina (singular: tegmen) simply means the leathery, thickened forewings of insects like cockroaches and grasshoppers. They are not for flying; they are hardened covers that shield the folded membranous hindwings underneath. In beetles this same idea appears as harder elytra.
A cockroach has two pairs of wings, so four wings in total. The prothorax (first thoracic segment) has no wings; only the mesothorax and metathorax bear wings. A common trap is thinking each thoracic segment carries wings.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
The forewings (tegmina) arise from the mesothorax and the hindwings arise from the metathorax. The prothorax bears no wings but carries the first pair of legs.
Tegmina are thick, tough and opaque, so they are too stiff to flap efficiently. Their job is to cover and protect the soft membranous hindwings when the insect is resting.
Cockroach morphology was rationalised out of the latest NCERT reprint of Structural Organisation in Animals, but the cockroach is still part of the NEET syllabus and questions on it (including wings) continue to be relevant.
Both are hardened forewings that protect. Tegmina (cockroaches, grasshoppers) are leathery and still slightly flexible, while elytra (beetles) are much harder and shell-like. In cockroaches the membranous hindwings still do flight.
