This week Hojun Song visited the Natural History Museum, London (after also visiting Philadelphia and Paris). Hojun's website (schistocerca.org) has a lot of information on this genus. It's well worth a visit.
There is a key to 43 Schistocerca species and a photo gallery in addition to background information on ecology, plagues, taxonomy and biogeography.
The image below if of Schistocerca obscura from Hojun's site.