These jewel-like bugs are known as Harlequin bugs. Their colours - bright metallic greens, blues and red make them easy to spot on the tree. These bugs suck sap from hibiscus plants and their relatives. Their main native food plant is the Beach Hibiscus (or Cotton Tree). The females (the big red bug on the left) lay clusters of eggs around twigs and guard them until they hatch. If disturbed, they emit a pungent odour. Phew!
(so don't be tempted to poke them with a stick :)
Cheerio for now,