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Lepidoptera Butterflies / Moths The name Lepidoptera, derived from the Greek words "lepido" for scale and "ptera" for wings, refers to the flattened hairs (scales) that cover the body and wings of most adults. |
Classification & Distribution
- complete development (egg, larva, pupa, adult)
Holometabola
Several classification systems have been proposed for dividing the Lepidoptera into suborders. Regardless of the system used, all of the larger and more economically significant families are members of a single suborder (Frenatae or Ditrysia).
Distribution: Common worldwide.
North America
Worldwide Number of Families 75135Number of Species 11,286>112,000Life History & Ecology
Lepidoptera (moths and butterflies) is the second largest order in the class Insecta. Nearly all lepidopteran larvae are called caterpillars. They have a well-developed head with chewing mouthparts. In addition to three pairs of legs on the thorax, they have two to eight pairs of fleshy abdominal prolegs that are structurally different from the thoracic legs. Most lepidopteran larvae are herbivores; some species eat foliage, some burrow into stems or roots, and some are leaf-miners.
Adults are distinctive for their large wings (relative to body size) which are covered with minute overlapping scales. Most entomologists believe that these scales are structurally related to the hair (setae) covering adult caddisflies. Lepidopteran wing scales often produce distinctive color patterns that play an important role in courtship and intraspecific recognition.
Although moths probably diverged from caddisflies in the early Triassic period, about 230 million years ago, adults in a few primitive families (e.g., Micropterygidae) still retain evidence of chewing mouthparts. In all other lepidopteran families, the mouthparts are vestigal or form a tubular proboscis that lies coiled like a watch spring beneath the head. This proboscis is derived from portions of the maxillae. It uncoils by hydrostatic pressure and acts as a siphon tube for sipping liquid nutrients, such as nectar, from flowers and other substrates.
From a taxonomic standpoint, the distinction between moths and butterflies is largely artificial -- some moths are more similar to butterflies than to other moths. As a rule, butterflies are diurnal, brightly colored, and have knobs or hooks at the tip of the antennae. At rest, the wings are held vertically over the body. In contrast, most (but not all) moths are nocturnal. They are typically drab in appearance, and have thread-like, spindle-like, or comb-like antennae. At rest, their wings are held horizontally against the substrate, folded flat over the back, or curled around the body.
Physical Features
Immatures
Adults
- Eruciform (caterpillar-like)
- Head capsule well-developed, with chewing mouthparts
- Abdomen with up to 5 pairs of prolegs
- Mouthparts form a coiled tube (proboscis) beneath the head
- Antennal type:
- Butterflies: knobbed or hooked at tip
- Moths: thread-like, spindle-shaped, or comb-like
- Front wings large, triangular; hind wings large, fan-shaped
- Body and wings covered with small, overlapping scales
Economic Importance
Although many Lepidoptera are valued for their beauty, and a few are useful in commerce (e.g., the silkworm, Bombyx mori), the larvae of these insects are probably more destructive to agricultural crops and forest trees than any other group of insects.
Bug Bytes
- Some butterflies (family Lycaenidae) are considered "endangered species". The Xerces blue (Glaucopsyche xerces) was last collected in 1943 from sand dunes near San Francisco, CA. This butterfly's name has been adopted by the Xerces Society, an organization dedicated to the preservation of endangered species.
- In flight, front and hind wings are linked together by a bristle (frenulum) or a membranous flap (jugum) so both wings move up and down in synchrony.
- According to folklore, larvae of the banded woollybear, Pyrrharctia isabella, can forecast the severity of winter weather. A wide brown band means the winter will be harsh, a narrow brown band means the winter will be mild.
- Adults of most Noctuidae and Arctiidae have "ears" in the thorax that help them detect and evade echo-locating bats. Some species of Arctiidae even produce high-pitched ticks that confuse the bats.
