Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Superfamily: Pentatomoidea
Family: Pentatomidae
SubFamily: Pentatominae
Tribe: Carpocorini
Genus: Monteithiella
Species: M. humeralis
Binomial name: Monteithiella humeralis
Synonyms: Antestia orbona, Pentatoma pallipes, Strachia humeralis
Common name: Pittosporum shield bug

Monteithiella humeralis is New Zealand native member of stink bug family: Pentatomidae
It is also present in Australia (Queensland, Tasmania, New South Wales South Australia), The known host plants are Pittosporum crassifolium, Pittosporum eugenioides, Pittosporum ralphii, Pittosporum tenuifolium from which they suck sap with specialised mouthparts.
Shield bugs have glands in their thorax between the first and second pair of legs which produce a foul-smelling liquid, hence they are commonly called stinkbugs. This liquid is used defensively to deter potential predators and is sometimes released when the bugs are handled carelessly. 

1-Pittosporum shield bug Monteithiella humeralis.JPG  

1-Pittosporum shield bug Monteithiella humeralis-001.JPG

1-Pittosporum shield bug Monteithiella humeralis-005.JPG  

1-Pittosporum shield bug Monteithiella humeralis-004.JPG

The glands between the first and second pair of legs which produce a foul-smelling liquid are visible in the photo below.
Pittosporum shield bug .Monteithiella humeralis 3 .JPG  

Photo showing Monteithiella humeralis's long specialised sucking and piercing mouthparts that are used to extract plant sap. The forelegs have been removed from this dead specimen to make the mouth tube visible.
Pittosporum shield bug Monteithiella humeralis.JPG  

Monteithiella humeralis on a Pittosporum eugenioides branch1-Pittosporum shield bug Monteithiella humeralis-002.JPG

Damage done to the leaves Pittosporum eugenioides (Lemonwood)1-Pittosporum shield bug Monteithiella humeralis-006.JPG

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/