Biology Of True Bugs
The true bugs have an incomplete metamorphosis, characterized by three life-history stages: egg, nymph, and adult. The nymphs resemble the adults somewhat in form, but they are not capable of reproduction. Most North American bugs overwinter at the adult stage.
Bugs have two sets of wings. The forewings of most species of true bugs are rather tough and leathery towards their base, and membranous farther away. This unusual forewing structure is the origin of the Latin roots of the name for the order: Hemiptera, or "half wing." The diagnostic, crossed-wing appearance of bugs at rest is also due to this unusual structure of the forewings, which form a well-defined "X" when held flat over the back of the abdomen with the membranous tips overlapping. The hind wings are fully membranous, and are used for flying. Some types of true bugs have greatly reduced wings, and cannot fly.
The mouthparts of bugs are adapted for piercing and sucking. The mouthparts comprise a pointed, elongate structure known as a beak or rostrum that arises at the front of the head, and folds backwards, quite far underneath the body in some species. The beak is itself made up of specialized stylets used for piercing, and others develop channels used for actual feeding. Most species of bugs feed on plant juices, but a few are parasites of vertebrates, living on the animal's surface and feeding on blood.
Most bugs have long, segmented antennae. Bugs have well developed, compound eyes, and adult bugs may have several simple eyes (or ocelli) as well. Many species of bugs have glands that give off a strongly scented, distasteful odor when the insect is disturbed.
Some species are quite brightly and boldly colored. Usually these bugs feed on plants that contain poisonous chemicals, which also occur in the bugs and render them distasteful or even toxic to potential predators. This type of boldly warning color scheme is known as aposematic coloration.
Most species of bugs are terrestrial, living on vegetation or in organic debris on the surface. Some species of bugs are specialized for living in aquatic habitats, occurring in the water column, or on the surface.
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