Do you recall which of your veges they were feeding on? The one that specialises in cucurbits (zucchini, cucumber, pumpkin etc) is identified at Epilachna sumbana on Canberra Nature Map. We had it on our cucs last season in large numbers. There's another species that goes more for Solanum family things.
In that case we can probably upgrade the ID to E. sumbana. I tried comparing your photo with ours but the angle was different so I couldn't be positive it was the same critter.