Butterfly Anatomy

Butterfly anatomy starts with three body segments:

Head

Thorax

Abdomen

Photo: Mexrix

The Head:

Two Compound Eyes - Most butterfly species have well developed vision. Each eye is made up of about 6000 small eyes.

Most species are sensitive to ultraviolet light spectrum. Ultraviolet light is able to display colors that we humans can't
see because of the wavelengths being too short. Different
flowers in your garden have ultraviolet makings that help appeal to butterflies as nectar sources.

All butterfly species see polarized light. Polarized is when light waves move in only one direction. It is believed the benefits of polarized light helps guide butterflies with direction to move about their habitat and to migrate.
Some species can see color. Those butterflies that can see color often see differently than we humans. For example, yellow tones to us can appear blue to some butterflies. It is recommended to have plenty of blooming colors in your butterfly garden. Because each butterfly species sees color differently, the more color you have the more butterflies will come.

Overall, the colors that attract the most species of butterflies are pink, purple and yellow.
Butterflies can see very well throughout their front, side and back any up close objects and movements. Their ability to see far away objects is limited.

Antennae are different for each Butterfly Species

Photo: Maumyhata

Two Antennae - Butterfly antennae come in different shapes and colors depending on species.

Butterflies are able to sense wind, nectar, scents and potential mates.
The antennae are often placed directly on object to sense them. It is also considered to be the primary olfactory organ.
Johnston's Organ - This is a sensory organ located at base of antennae (called pedicel) that is used to detect sound and motion. This organ is commonly used to find a mate by detecting the sound and wing beats which vibrate the antennae.
Swallowtail butterflies have a Y-shaped defense organ called Osmeterium at base of antennae. When feeling threatened caterpillar pushes it out and releases a pungent chemical. Check out video on butterfly host plants page to see a neat trick how gardeners can see osmeteria.

Photo: Antoine Beyeler

Proboscis - This is the butterfly tongue. It consists of two elongated interlocking halves. They are like two straws that are used to transfer liquid. The above pictures shows the palpi. These are the vertical lips that protect the proboscis.

Once the butterfly emerges from it's pupa the two separate elongated halves must be 'zipped' together for the proboscis to work properly. If this isn't done correctly the butterfly will die.
Butterflies receive their nourishment in liquid form. Pollen and other butterfly foods are broken down by enzymes excreted through the proboscis in order for nutrients to be taken in.
With exception, very rarely will butterflies have any chewing mouth parts as they did at their caterpillar stage.

The Thorax:

The mid-section and also called the chest. It has:

Thorax of butterfly is where major muscles are found

Six jointed legs
and the muscles that move them.

One family of butterfly, the Nymphalidae or Brush Footed, have the same 6 legs but the front is called a 'Proleg'. These 2 front legs are smaller and allow them to taste their food.

Four wings
and muscles that move them.

Butterfly wings are not hooked together. Unlike butterfly anatomy, the wings of moths are hooked together.

Photo: Veruska1969

The Abdomen:

The abdomen is also called the tail.

Usually Narrow. Most vital organs such as the heart, reproductive organs and the majority of the digestive system are located in abdomen of butterfly anatomy.
Male butterflies have light receptors in their abdomens which are connected to their sexual organs. It was discovered that when these light receptors darkened, it was then the male would transfer his sperm packet to the female.
This is where female butterflies produce eggs. Female butterflies also have light receptors, but these are not used for mating purposes. It is still unclear as to the purpose of these receptors.
While caterpillars excrete solids called frass, waste materials pass through butterflies by long filaments found throughout the body. These filaments are called malpighian tubules found in the abdomen. The waste passes through these tubules by hemolymph, or blood. Waste is usually clear and a liquid. It exits the butterflys hindgut, or rectum, by release of a few drops.

Close up of the butterfly and it's anatomy. (No sound)

Other butterfly anatomy information:

Butterflies have an exoskeleton, not a skeleton. The exoskeleton is made of many layers of chitin. It is hard and waterproof helping protect inner tissue. It also helps the butterfly to retain moisture and is hard to chew offering protection from predators. The exoskeleton also helps in preventing parasites and disease to penetrate to the inside butterfly anatomy.

Chitin is a polysaccharide found in the exoskeleton of the butterfly and other insects. It is a polymer composed of repeating bonded structural units.
Butterflies have a Brain, Heart and Stomach. They also have blood, called hemolymph. Their blood does not circulate or have the healing properties like ours. This is why when the wings of butterflies are torn they do not heal or grow back, although hemolymph does travel through the veins on wings.
Butterflies get their air through Spiracles, called tracheae, that run down each side of their body made up of nine pairs of pores. The thorax requires more oxygen than any other part of the butterfly anatomy. This is because the muscles that move the legs and wings require more.
Butterflies also have sensory hairs all over their body called Setae. Setae can be sensitive to smell, touch and sound. Setae are also called scales.
Some species can hear while other species can make clicking sounds, usually for mating. The butterfly sensory system includes: