Nezara viridula is not a fussy eater; they'll readily eat over 200 species of plant. Likewise, they will suck the sap from the fruits, seeds, leaves and stems of the plants they attack.
The Southern Green Shield bug is strikingly similar to our native Common Green Shield Bug. The Southern Green was first found breeding in the London area back in 2003. You can tell these two bugs apart from a few simple tricks.
Firstly, the Southern Green Shield bug is slightly larger than that of our native. Also, these bugs lack the darkened brown area near the tip of the abdomen, as seen on the Common Green.
Luckily these bugs aren't too much trouble as they tend to be most abundant towards the end of the harvesting season.