Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Hemiptera (True Bugs, Cicadas, Hoppers, Aphids and Allies)
Suborder: Heteroptera (True Bugs)
Infraorder: Pentatomomorpha
Superfamily: Pentatomoidea
Family:   Pentatomidae (Stink Bugs)
Common names: Stink beetles, Stinkbug, Shieldbugs. Stink bug

Pentatomidae is one of the largest heteropteran families (true bugs), with almost 5000 species in ~900 genera of 10 subfamilies worldwide. The stink bug derives its name from its tendency to eject a foul smelling glandular substance secreted from pores in the thorax when disturbed. The chemicals involved include aldehydes, making the smell similar to that of coriander; whether or not a human finds the smell unpleasant or pleasant may be genetic. In some species, the liquid contains cyanide compounds with a rancid almond scent. This is a form of anti-predator adaptation.

Many stink bugs and shield bugs are considered agricultural pest insects, because they can create large populations which feed on crops (damaging production), and they are resistant to many pesticides.

A small 3mm Pentatomidae bug on a flower petal.
 

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