Table Mountain hopper (nymph?)

There was talk that this may be a milkweed locust nymph. Is this true? I have seen these small nymphs often in fynbos around Kleinmond, sometimes with red instead of green colouring. I have never seen one in excess of about 15mm long, and have tried to rear them through to adulthood on a variety of food plants but having no experience with grasshoppers my success rate is zero to date. Is there a special trick other than the usual ventilation, fresh and correct food, and clean housing?