When I looked it up in my "Essential Illustrated Guide to Southern African Wildlife" by Readers Digest, I saw that it is called a Stink Locust (because, when threatened, it emits a vile-smelling yellow fluid ) or a Gaudy Grasshopper.
This guy only has short, non-functional wings so when in danger, it can do no better than just hop away. The bright colours, however, serve as a warning to predators. Apparently they're a pest for fruit trees and vegetables but I've never had a problem with them. I use no pesticides in my garden. All are welcome to visit or live in my garden.
When I returned to South Africa in 2006 and began to revamp my garden in earnest, my husband showed me a fellow similar to the one above crawling up one of the shrubs. He said: "You'd better kill it, or it will wreck your garden" (Ole drama king!) I said, no, just leave nature to itself but I could see he didn't believe me. A few hours later he called me and excitedly pointed to a thorn on the acacia tree. A locust had been caught and hung there by the Common Fiscal which is also known here as Jackie Hangman or the Butcher Bird. This neat black and white bird is part of the shrike family and hangs it's food on barbed wire fences or on thorn tree spikes until it's ready to eat it.
I looked at hubby and said: "Well dear, I rest my case..."