The
scutellum is the posterior portion of either the
mesonotum or the
metanotum of an
insect thorax; 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. In
Diptera and
Hymenoptera the scutellum is nearly always distinct, but much smaller than (and immediately posterior to) the
mesoscutum.