I.

Introduction

Butterflies and Moths, insects distinguished by four wings covered with tiny, shingle-like scales and by mouthparts that form a hollow, flexible tube like a drinking straw. Most butterflies and moths use their distinctive mouthparts to feed on the nectar of flowers. The insects have proportionately small bodies and large wings, and a pair of antennae on their heads. Butterflies and moths together make up the second largest order of insects, called Lepidoptera (Greek lepis, “scale”; ptera, “wing”).

Butterflies and moths are similar animals, but they have some general differences. The main difference is that butterflies have knobs, or clubs, on the tips of their antennae. Moths may have threadlike, feathery, or blunt antennae, but their antennae lack clubs. In addition, most moths tend to fly chiefly at night, while butterflies are active during the day. When at rest, most moths hold their wings folded flat over their backs, while butterflies hold their wings upright over their backs or bask with them spread flat out to the side. Many species of moths have dull gray or brown wings, and butterflies often have wings with colorful patterns. But numerous exceptions exist. For example, many moths fly during the day and are brightly marked, and many butterflies have soft, brown wings.

Throughout history, lepidopterans—especially the colorful butterflies—have been admired for their delicate beauty. They have a prominent place in art and literature as symbols of freedom, creativity, and the beauty of nature. The animals are also crucial parts of the ecosystems in which they live. Their most important ecological role is in pollination, the transfer of pollen from one flower to another, which helps plants to reproduce. Butterflies and moths pollinate many wild plants as well as important crops grown by humans for food.

By far the majority of lepidopterans are moths. Scientists have identified some 200,000 species of moths and suspect there may be many more not yet discovered, perhaps amounting to a million or more species. By contrast, the approximately 18,500 known types of butterflies probably account for most of the world's butterfly species.

Lepidopterans probably arose between 200 million and 300 million years ago from insects similar to present-day caddisflies, night-flying insects that live near water. After flowering plants, on which butterflies and moths depend for food, arose about 130 million years ago, the insects developed and diversified rapidly. The earliest known fossils of primitive moths, found in Lebanese amber and Siberian sediments, are 100 million to 130 million years old. The oldest known butterflies in the fossil record date from about 48 million years ago, and many butterfly fossils are found in shale about 38 million years old from the Florissant Fossil Beds of Colorado. Some of these fossil butterflies closely resemble present-day species.