mes·o·tho·rax 
(mĕz′ə-thôrăks′, mĕs′-)
(mĕz′ə-thôrăks′, mĕs′-)n. pl. mes·o·tho·rax·es or mes·o·tho·ra·ces (-thôrə-sēz′)
The middle of the three divisions of the thorax of an insect, bearing the middle pair of legs and the first pair of wings.
mes′o·tho·racic (-thə-răsĭk) adj.