part of adult thorax notum TGMA:0000426 TGMA:0000426 The tergum of a thoracic segment comprising the primary segmental sclerotization and the preceding intersegmental sclerotization, the acrotergite. In most winged insects, the acrotergite of the mesothorax remains as a narrow anterior strip of the mesonotum while the acrotergite of the metathorax becomes the postnotum of the mesonotum. As in other Pterygota, the mesonotum of mosquitoes has retained the acrotergite and is defined in the classical sense as the notum of the mesothorax. Although it is understood that the notum of the metathorax includes the mesopostnotum, the term "metanotum" is customarily applied to the primary segmental sclerotization only. default_namespace