This is a Caddis imitation found in abundance in our Rivers.
A great pattern for Yellowfish on the Vaal or Orange rivers, bright green with a tungsten bead will ensure it will get down quickly where it needs to be. The Z-wing (Zelon material for the wing) imitates a caddis getting ready to emerge. If you start to see a few Caddis coming off the surface late afternoon, tie this on and you should see some results.
Often tied as a dropper fly with trailing nymph pattern on the point, helping to get the flies to the bottom of the river. The bright orange bead is very effective in slightly discoloured water like the Vaal.
Use the #14 in slow-flowing or shallow sections, step up to the #10 in the faster, deeper sections.