BUTTERFLIES AND MOTHS (Part 1 of 2)

DEFINITIONS:

BUTTERFLY: 1 any of various families of lepidopteran insects active in the daytime, having a sucking mouth part, slender body, rope like, knobed antennae, and four broad, usually brightly coloured, membranous wings 2 a person, esp. a woman, thought of as flitting about like a butterfly and being frivolous, fickle, etc. 3 a) short for BUTTERFLY STROKE b) a contest in which each contestant uses a butterfly stroke.

MOTH: 1 any of various families of four-winged, chiefly night-flying lepidopteran insects, similar to the butterflies but generally smaller, less brightly coloured, and not having the antennae knobed.

Lepidoptera, the order of scaly-winged insects including butterflies, moths, and skippers.

To a poet butterflies and moths are like fluttering flowers. Scientists know them as a group of insects that make up the order Lepidoptera, meaning "scale wings." They are so named because their wings and certain portions of their bodies are covered with a fine dust.

Under a microscope the dust is seen to be made up of millions of finely ridged scales that are arranged in overlapping rows. Each scale has a tiny "stem" that fits into a cup like socket. The beautiful colours and markings of the insect are due to the scales, which come in a remarkable variety of colours.

Butterflies and moths look very much alike. The best way to tell them apart is to examine their antennae, or feelers. Butterfly antennae are slender and the ends are rounded into little clubs or knobs. Moth antennae lack these knobs. Many of them look like tiny feathers, and some are threadlike.

Most butterflies fly and feed during the daytime. Moths fly at night. Butterflies rest with their wings held upright over their backs, and moths with their wings outspread. These are not safe rules to follow, however, for some moths are lovers of sunshine and some fold their wings. The honours for beautiful colouration are about evenly divided. The pale green luna moth and the rich reddish brown cecropia moth are as handsome as any of their gay cousins.

Different kinds of butterflies and moths live throughout the world in temperate regions, high in snowy mountains, in deserts, and in hot, steamy jungles. They vary in size from the great Atlas moth of India, which is 10 inches from tip to tip of the spread wings, to the Golden Pygmy of Great Britain, which is only 1/5 inch across. In North America north of Mexico there are 8,000 kinds of moths, but only 700 kinds of butterflies.

Like all insects, the butterflies and moths have three pairs of legs and a body that is divided into three sections head, thorax, and abdomen. On the thorax, or middle section of the body, are two pairs of wings. The pair in front are usually the larger. The scales on the wings contain a pigment that gives the insect some of its colour.

Certain colours, however, and the iridescent shimmer come from the fine ridges on the scales. The ridges break up the light into the various colours of the spectrum. The beautiful blues, for example, are due to the way in which the light strikes the scales.

These insects feed on the nectar of flowers and on other plant liquids. The mouth is a long slender sucking tube. When it is not in use it is coiled up like a delicate watch spring. By uncoiling the tube, the insect probes deep into the flowers and sucks up the nectar. Some kinds of insects have spines on the tip of the tube that tear the plant tissues of ripe fruits and start the juices flowing. Certain kinds have imperfectly developed mouth parts and do not feed at all. Soon after they become adult insects they mate, lay their eggs, and then die.

As the adults visit the flowers in search of nectar, they rub against the stamens and pistils, and so help in the process of pollination. The pronuba moth that pollinates the desert yucca is particularly interesting in this respect.

The Life Cycle Metamorphosis

Butterflies and moths go through a life history known as complete metamorphosis. (The word means "change of form.") The female lays many eggs. From these hatch tiny larvae called caterpillars. At this time of their lives they become pests, devouring the food plants of man. The female always lays its eggs on the kind of plant that the caterpillars will use for food.

After several moults (skin shedding) the full-grown caterpillar is ready to turn into a pupa. At this stage the butterflies and the moths differ. Butterflies spin a button of silk that adheres to a twig, leaf, or other solid support. They then cling to the button by a sharp spine at the end of the body and moult for the last time. As the old caterpillar skin peels off, there appears a naked pupa called a chrysalis. It is an "insect in the making," encased in a tough, flexible shell.

Cocoon, envelope, often largely of silk, which an insect larva forms around itself.

Some moth caterpillars spin silken cases called cocoons inside which they pass the pupal stage. Others burrow into the ground, about six inches below the surface. There the caterpillar moults for the last time. The pupa is covered with a hard, dark, sticky substance that protects it from cold and moisture and from attacks of other insects.

The time spent in the chrysalis or cocoon varies with the kind of insect and with the time of year. It may be weeks or months. The pupa does not appear to be alive, but marvellous changes are taking place. Most of the organs and other tissues of the caterpillar break down, turning into a semi liquid.

From this material are formed the wings, legs, and other parts of the adult. At last the adult is ready to leave the pupa case. If it is an earth-burrowing kind, the pupa, before it opens, is raised to the surface by means of thrashing movements of the insect on the inside. After the insect has freed itself it is wet and its wings are soft and limp. It slowly fans the wings to pump air into the veins. Gradually the wings expand and harden. In a few hours the adult is ready to fly and to seek a mate. Most adults live from four to six weeks. Some live only a few days, some can live as long as ten months.

Enemies and Defences

Butterflies and moths have many enemies. Birds are among the worst. Various kinds of flies and wasps lay their eggs on or in the bodies of the caterpillars, so the larvae dig in and feed on the tissues.

Sphinx moth (or hawk moth), any of the order Lepidoptera, family Sphingidae; especially the tomato-worm sphinx (Protoparce quinquemaculata); moths are excellent pollinators of plants.

Both caterpillars and adults have ways of defending themselves. Stinging hairs and spines that may be poisonous protect some caterpillars. The woolly bear caterpillars are covered with a fuzz that makes them an unpleasant mouthful. "Frightfulness" is a defence of quite harmless creatures, such as the hickory horned devil with its red horns, the ugly tomato worm, and the caterpillar of the sphinx moth.

Monarch butterfly, insect (Danaus plexippus) of the order Lepidoptera, family Danaidae; breeds on milkweeds.

The monarch butterfly has a foul taste and odour that birds have learned to avoid. The tasty little viceroy butterfly looks exactly like the monarch, only smaller, and for this reason is also avoided by birds. In addition, many butterflies and moths at rest resemble dead leaves or the twigs and bark of trees.