EARWIGS may have the most economical chemical weapons in the insect
world.
When threatened, earwigs spray irritant chemicals called quinones from glands
on their abdomen. Thomas Eisner of Cornell University and his colleagues have
found that the quinones are stored as crystals, which are dissolved by another
chemical called pentadecane when required (Chemoecology, vol 10, p 81).
The openings of the glands are tiny, however, so any undissolved crystals are
not expelled and wasted.
