Pentatomidae, Greek pente meaning five and tomos meaning section, are a family of insects belonging to order Hemiptera including some of the stink bugs and shield bugs. The scutellum body is typically half of an inch long, green or brown color, usually trapezoidal in shape, giving this family the name "shield bug". The tarsi are 3-segmented. The forewings of stink bugs are called hemelytra, with the basal half thickened while the apex is membranous (as are the hindwings). The stink bug, also called stinkbug, 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 antipredator adaptation. Since recent arrival in the USA, populations of the brown marmorated stink bug have significant.
The idiomatic term "stink bug" is also applied to distantly related species such as Boisea trivittata, the "boxelder bug", and entirely different types of insects such as beetles in the genus Eleodes ("pinacate beetles").
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. They are a threat to cotton, corn, sorghum, soybeans, native and ornamental trees, shrubs, vines, weeds, and many cultivated crops. However, some genera of Pentatomidae are considered highly beneficial: the anchor bug, which can be distinguished by the red-orange anchor shape on the adult, is one example. It is a predator of other insects, especially Mexican bean beetles, Japanese beetles, and other pest insects.
Spined soldier bug, Podisus maculiventris preying on larvae of Epilachna varivestis
Anchor bug (Stiretrus anchorago) valued as a predator on crop pests.
They also are commonly eaten in Laos, and are regarded as delicious due to their extremely strong odor. The insects are sometimes pounded together with spices and a seasoning to prepare cheo, a paste mixed with chilies and herbs.
There are several subfamilies, of which the Australian Aphylinae is often given family status, but is here retained as a subfamily, following Grazia et al. (2008).