in zoology, organ found in bees, many wasps, some ants, and in scorpions and sting rays, used defensively as well as to kill or paralyze prey. In the bee and the wasp the venom
is produced by glands associated with the ovipositor (egg-laying organ) of the female. As symptoms differ, it is assumed that the venom of each species of insect probably has slightly different chemical properties. The bee's "acid gland" produces histamine and proteinlike substances that are extremely dangerous to persons with specific allergies to them. Adrenaline injections may be lifesaving in such cases. In the honeybee the sting is a minute needle with tiny serrated edges, the teeth of which point backward. This makes it hard for the insect to pull the organ loose and often results in the fatal loss of the sting, the poison gland, and part of the intestine. Hornets, yellow jackets, and other wasps have sharp, smooth stings that can be used repeatedly. A few ants produce formic acid as a venom. The scorpion kills its prey with poison injected by a curved spine at the tip of its tail; the wound is painful to human adults and may be fatal to children. Strictly speaking, spiders bite rather than sting, since they inject their venom by means of fanglike cheliceras. Coelenterates, e.g., the hydra, jellyfish, and certain corals, are equipped with stinging capsules (nematocysts) consisting of a trigger mechanism that, when stimulated, raises the hydrostatic pressure of the cell so that hollow venom-bearing threads are ejected with enough force to pierce the prey. The larger coelenterates, e.g., the Portuguese man-of-war and Cyanea,
are dangerous to man. The stingrays, or stingarees, have long whiplike tails bearing one to three sharply toothed, bony, poisonous stingers capable of inflicting painful wounds.
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