The scutellum is the posterior portion of either the mesonotum or the metanotum of an insectthorax; however, it is used almost exclusively in the former context, as the metanotum is rather reduced in most insect groups. In the Hemiptera, and some Coleoptera, the scutellum is a small triangular plate behind the pronotum and between the forewing bases.[1] In Diptera and Hymenoptera, the scutellum is nearly always distinct, but much smaller than (and immediately posterior to) the mesoscutum.
^Richards, O. W.; Davies, R. G. (1977). Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development; Volume 2: Classification and Biology. Berlin: Springer. ISBN0-412-61390-5.
