Jewel stink bug (likely harlequin shield bug)

Eucalyptus woodland, gardens, shrublands, and other warm habitats in Australia and nearby regions.

Adults and nymphs suck plant sap, especially from eucalyptus and related plants, using piercing-sucking mouthparts.

Usually lives on foliage in groups; nymphs are brightly colored and molt through several stages. Adults can release a strong defensive odor when disturbed and may fly readily.

Harmless to people, though it can damage ornamental plants or young shoots when abundant. It is part of native food webs and contributes to ecosystem biodiversity.