Butterfly Basics
Lepidoptera
Butterflies and moths belong to a group of insects called Lepidoptera. Like all insects, butterflies and moths have a head, thorax, abdomen, two antennae, and six legs.
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There are many more species of moths than butterflies. Butterflies and skippers make up about 10% of the Lepidoptera order, while moths make up 90%.
Moths and butterflies have four wings that are almost always covered by colored scales, and a coiled proboscis for drinking liquids such as flower nectar.
Butterfly or Moth?
- Butterflies are active during the day, while moths tend to be noctural.
- Butterflies tend to fold their wings vertically up over their backs. Moths tend to hold their wings in a tent-like fashion that hides the abdomen.
- Butterflies are typically larger and have more colorful patterns on their wings. Moths are typically smaller with drab-colored wings.
- Some moths have wingless adults and some primitive moths lack a proboscis. Moths have a frenulum, which is a wing coupling device that ensures the wings travel together during flight. Butterflies do not have this.
- Moths build a cocoon wrapped in a silk covering. A butterfly makes a chrysalis, which is hard and smooth with no silk covering.
- The antennae of butterflies have a swelling at their end; moths have no such "club" and instead are more feathered. Moth antennae tend to be leaf or feather shaped (compare the two images below).
Butterfly (l) and moth (r) side-by-side comparison![]() |
Parts of the Butterfly
- Head - Includes two clubbed antennae, two large eyes and a long proboscis
- Eyes - allow excellent sight of a large spectrum of colors
- Thorax - muscular area attaching the six legs and four wings
- Abdomen - behind the thorax, a long tubular area of eleven segments housing the digestive system
- Wings - Butterflies have four wings covered with scales, two on each side of the abdomen: the forewing (FW) and the hindwing (HW). The forewings are larger and longer. Hindwings are typically more rounded.
- Legs - six jointed legs with feet-like clawed tarsi ... they can taste with these "feet"
- Antennae - feature a club at the end and chemical receptors for smelling; also used for touching
- Proboscis - a tubular feature for drinking and sipping, like a straw. When not in use, it is rolled up under their head.
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What is the Life Span of a Butterfly?
Different butterfly species have different life spans, and actual survival rates depend on factors such as weather and predators. An average butterfly species has an adult life of 2-4 weeks, or less.
Some live much longer, like the Mourning Cloak, which may live almost a year, and hibernate during winter. The last generation of Monarchs each year lives through the winter at the end of their fall migration into Mexico, living a period of up to seven months. Others overwinter in the adult stage.
What do Butterflies Eat?
Most adult butterflies drink nectar from flowers through their "tongues". A smaller number of butterflies never visit flowers, but gaining sustenance from tree sap, rotting animal matter, and other organic material.
Butterfly caterpillars almost always eat plant matter.
Is the Butterfly a Pollinator?
While the best-known pollinators may be honeybees and bumblebees, butterflies do their part to help with the pollination of plants and flowers, and ultimately seed and food production.
Why are Butterfly Colors so Important?
As day-flying insects, butterflies are often brightly colored, as are some day-flying moths, to communicate with each other. Night-flying insects typically have dull coloration because bright colors are unimportant at night when they can't be seen.
Another function of coloration is to help an insect find a potential mate; colors advertise the species and sex of an individual. In species like the Monarch, colors may also communicate distastefulness to predators such as birds. Through the process of mimicry, some butterflies escape predators by resembling bad-tasting species.
Do Butterflies Migrate?
Yes, some do, others do not. Monarch butterflies (Danaus plexippus) are known for their long-range 3,000 mile mass migration that brings millions of them north in the spring, and back to California and Mexico each winter.
The American Snout (Libytheana carinenta) is known to be migratory, and some years the migrations are so massive as to darken the sky. It migrates around Central and South Texas following late summer rains, seeking fresh growth on Hackberry trees.
More species also migrate, such as the Cloudless Sulphur, Gulf Fritillary, Painted Lady, American Lady, Red Admiral, Common Buckeye, and others.
More Butterfly Facts
- They love warm weather! They cannot fly if their body temperature is below about 85 degrees
- Peru has more butterfy species than any other country ... about 3,700!
- They shelter under leaves during rain or stormy weather, and at night
Scientific Family Classifications
Butterflies and moths with the same or similar characteristics are classified in groups called "families". As an example, most of the largest butterflies in the world, many with tail-like projections on the hindwings, are placed together in the Swallowtail family, scientific name Papilionidae.
- Papilionidae - Swallowtail butterflies, most species having prominent tails.
- Hesperiidae - Skippers - relatively small, fast-flying species.
- Lycaenidae - Blues, Hairstreaks and Coppers. Colors and patterns of sexes often differ.
- Nymphalidae - Brush-footed butterflies, contains many subfamilies.
- Pieridae - Yellows and Whites, with those predominant colors.
- Riodinidae - Metalmarks, sometimes placed in the Family Lycaenidae.
Studying the Butterfly: Dorsal and Ventral Views
When studying about butterflies, and reading books about them, you will often see references to "dorsal view" (wings open) and "ventral" view (wings closed). See example photos below.
Painted Lady (dorsal view)![]() |
Painted Lady (ventral view)![]() |
Butterfly Life Cycle: A Complete Metamorphosis
The life cycle consists of four stages:
- Egg - A butterfly starts life as a very small, round, oval or cylindrical egg laid on the leaf of a "host plant"
- Larva (caterpillar) - once the egg hatches, the larva eats the host plant on which it was placed. As the larva grows, they "molt" several times, becoming larger through each step, or "instar".
- Pupa (chrysalis) - as the larva reaches its full size, it transforms itself into sack in which it will make the final transformation into an adult.
- Adult butterfly
After mating, the female butterfly lays small round or oval eggs on a “host” plant as shown to the right. Butterflies lay their eggs on plants that will be eaten by the caterpillar when it hatches from its egg. For example, the Monarch butterfly lays her eggs on Milkweed, while the Black Swallowtail will usually lay eggs on dill or fennel. |
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The eggs hatch into caterpillars within a few days, or within months or even years, depending on the species and weather conditons. Monarch Butterfly caterpillar ... 7 days from egg laying ... size compared to a straight pin (right).
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Eating, and growing, daily! |
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As the caterpillar reaches maturity, it transforms itself, or "pupates", into a "pupa", or chrysalis like the Monarch chrysalis shown here. |
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As the Monarch chrysalis ages, it becomes dark and clear, with the butterfly evident inside, ready to emerge. |
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After several days or weeks, the adult butterfly emerges, completing the amazing life cycle!
In the photo to the right, we see a beautiful new Monarch Butterfly ... minutes after emerging from 10 days in its chrysalis! |
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Common Butterfly Species
It is estimated that there are about 20,000 species of butterflies in the world. They are found in every continent except Antarctica. In North America, there are 725 species (north of Mexico), with about 575 of these occurring regularly in the lower 48 states of the United States. Included on this website are some of the more common butterflies found in residential areas, nearby parks and gardens, and while hiking in the open spaces.
Common Moths
Polyphemus Moth Promethea Moth Salt Marsh Moth Snowberry Clearwing Moth Spiny Oakworm Moth Tersa Sphinx Moth White-lined Sphinx Moth |