The cockroach has two pairs of wings which are attached dorso-laterafly to die mesothorax & metathorax. First pair of wings are thick, hard & leathery. They are called as tegmina or elytra or coverites. The tegmina covers the 2nd pair of wings during rest. The second pair of wings are thin, transparent & membranous. During rest, they remain folded below the first pairs of wings. The wings have a network of veins containing haemolymph at the time of formation. Later on. the blood dries up & tire network of veins act as an endoskeleton. Now, they are called as nervures. Hie wings are formed as evagination of the body wall between the tergum & pleuron. Well developed wings have only two layers of the cuticle. The basal part of the each wing is attached to the sternum with the help of basilar muscle. There is a pair of tergostemal muscles in each thoracic segment which are attached between the tergum & the sternum and are also called as dorso-ventral muscles. The contraction & the relaxation of the basilar muscles and tergostemal muscles are responsible for the movement of the wings.
