Pentatomidae, generally called shield bugs or stink bugs. However, the term shield bugs are also applied broadly to include several related families (e.g. Acanthosomatidae, Scutelleridae, and Cydnidae), or specifically only to refer to species in the family Acanthosomatidae. The term shield bug refers to the generalized body shape of adult bugs in these families which resembles a heraldic shield when viewed from above.
The American name “stink bug” is specific to the Pentatomidae and refers to their ability to release a pungent defensive spray when threatened, disturbed, or crushed. The composition of this spray may vary between species, and even by sex or age, but generally includes aldehydes and alkanes. Descriptions of the smells vary widely, and include oily, dusty, woody and earthy, and like coriander. In some species, the liquid contains cyanide compounds and a rancid almond scent, used to protect themselves and discourage predators.
Pentatomidae is the largest family in the superfamily Pentatomoidea and contains around 900 genera and over 4700 species. As hemipterans, the pentatomids have piercing sucking mouthparts, and most are phytophagous, including several species which are severe pests on agricultural crops. There are, however, some species, particularly in the subfamily Asopinae, that are predatory and may be considered beneficial.