The poor old shield bug has the unenvious title
of being called a stink bug. All because it has a
small gland in its thorax which produces a horridly
foul smelling liquid when provoked. Potential predators
and human alike retreat once they get a whiff of the
odour. For any of you who really care the stench comes
from what is known as aldehydes and it takes a good
scrubbing to get off your hands. The
bug gets its 'other' name from the
distinctive triangular looking shield on their thorax.
Characteristics of a Shield
Other than the fact that they stink, some
Shield Bug's are predatory and love nothing better than
skewering their victims (often a slow moving caterpillar)
with their rostrum. Once impaled the Shield Bug will
slowly drain the victim of its body fluids. Another
distinguishing feature is that the pronotum (dorsal)
exoskeletal plate often extends out from the sides.
Both the nymphs and the adults have piercing mouthparts to
suck sap from plants or juices from other insects.