Moths and Butterflies
Nature Bulletin No. 192-A May 15, 1965
Forest Preserve District of Cook County
Seymour Simon, President
Roland F. Eisenbeis, Supt. of Conservation
MOTHS AND BUTTERFLIES
Moths and butterflies include some of the largest and some of the most
beautiful insects, as well as some quite small and many of the most
harmful. There are approximately 80, 000 species -- more in the
tropical regions than elsewhere -- and far more moths than butterflies.
Of about 10,000 that occur in America north of Mexico, only about
600 are butterflies, including a few that range north of the Arctic
Circle. In the next two bulletins we shall endeavor to make you
acquainted with some of our most common or spectacular kinds.
Moths and butterflies have four scaly wings. If you handle them, what
appears to be dust comes off on your fingers. These dust particles are
minute scales, each a flattened hollow bristle with fine ridges on the
upper side. It is the pigments in these scales, which on many
butterflies and moths cover each wing like overlapping shingles on a
roof, that produce the colors and markings. Metallic iridescent colors
are due to the reflection or refraction of light by the tiny ridges. In
some cases, generally the males, certain scales are outlets for scent
glands producing an odor which, when perceptible to humans, has a
musky or flower-like fragrance.
Moths and butterflies -- except some kinds which do not eat at all
during their short lives as adults -- differ from other insects by having
a long thread-like hollow sucking-tube through which fluids, such as
nectar from flowers, can be pumped up and which, when not in use, is
coiled up like a watch spring in front of and beneath the head. Some of
the hawk or sphinx moths have tongues over 6 inches long, more than
twice the length of their bodies. Moths and butterflies have two large
compound eyes, each of which has thousands of facets. Between them
are two conspicuous antennae. All butterflies have thread-like
antennae, each with a knob or club-like thickening at the tip. The
antennae of many moths are plum-like; others are like combs; others
are thread-like, sometimes curving backward near the end, but only in
rare cases is there a knob at the tip.
There are other differences between moths and butterflies which hold
true in most cases. All of our butterflies fly only in daytime. A few
tropical butterflies and most moths fly at night or twilight, some of
them seldom before midnight, and are attracted by lights. However,
some moths fly only in daytime; some in both daytime and night-time;
in some species only the female flies in daytime. Butterflies at rest,
with few exceptions, fold their wings together in a vertical position
above the back. Moths at rest either wrap their wings around the body,
or spread them out horizontally, or fold them roof-like over the
abdomen. Only a few kinds of moths fold them in a vertical position
when at rest.
All moths and butterflies, being insects, have six legs although the two
front legs of some are small and useless. But there is one thing they all
have in common: they lay eggs which hatch into crawling larvae
called caterpillars, which eventually change into helpless pupae --
some in cocoons and some not -- from which emerge the winged
Many moths and butterflies are beneficial because they insure the
pollination of favored plants by carrying pollen from one flower to
another as they visit them to drink the nectar. And everyone has heard
about the silkworm moth of Asia. None of our American butterflies is
seriously harmful except the white Cabbage Butterfly which was
accidentally introduced into this country and Canada from Europe. But
among the moths, in their larval stage, are many of our most
destructive pests. One of these, the little Clothes Moth, probably
plagued our ancestors when they wore nothing but animal skins.
We have provided them with "a more abundant life. "
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Update: June 2012