Middle of the three main body regions of apocritan Hymenoptera, which looks like the insect thorax but is composed of the thorax plus the propodeum; sometimes called the alitrunk. [drawing

In Apocrita, the thorax plus the propodeum (cf. thorax).

The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings.