Yes, quite a bit. They are in two different orders of insect. Mantises form their own order, Mantodae. Grasshoppers are a grade in the order Orthoptera. Manodea and Orthoptera branched off from a common stem maybe in either the Permian or Triassic period. read more
Praying mantises (Mantidae) and grasshoppers (Caelifera) are both noted for their impressive legs. These two insect species are not closely related, but have evolved independently to have some rather impressive leg adaptations. read more