Butterflies have always captured the wonder of my girls. Those beautiful, delicate wings and amazing stories of long migrations across the land. We feel especially lucky if one happens to allow us to study them up close and land on a shoulder or hand. Today we are exploring butterfly anatomy with our Free Butterfly Anatomy activities and discussing the different parts of a butterfly in this post.
What are the parts of a butterfly?
Like all insects, a butterfly has three main body parts: the head, thorax, and abdomen. Let’s take a closer look at each section.
1. Head Butterfly Anatomy
Butterflies use their head just like we do. It has the parts they need to sense what is going on in the world around them, and allows them to feed.
Butterflies have two large compound eyes on either side of their head. Each is made up of thousands of little lenses called facets that individually see one small part of the larger image around them. Its their brain’s job to piece all these smaller images together like a mosaic. Each facet faces in a slightly different direction because of the rounded (convex) curve of their eye’s surface. This allows them to see a much larger angle view of the world than we do. Individual facets are part of a larger unit called an ommatidium which has the lens, cornea, and photoreceptor cells that can detect color and shape. They even have photoreceptors for UV light which is invisible to our own eyes. Flowers take advantage of this by having nectar guides to lead the butterfly straight to their source of food. It’s like the lights along the runways that guide planes when they are landing.
A butterfly’s nose and fingers is their antennae. They can smell flowers and special chemicals, called pheromones, that help them find a mate. Antennae are also used to help the butterfly balance and orient themselves when flying. Light receptors in their antennae allow them track the sun’s position to tell the difference between night and day.
Butterflies don’t have mandibles like some insects that work like jaws to eat their food. Instead, they drink the sweet nectar through a straw like tongue called a proboscis. When a butterfly first emerges from their crystalis, one of the first things that happens is the two sides of the proboscis merge into one. It curls up when they are not using it, and uncoils into a long tube when they are ready for a snack.
2. Thorax Butterfly Anatomy
The thorax is the center of activity for our butterfly! It has all the muscles that move the legs and wings.
As an insect, butterflies have three sets of legs (six in total) – the forelegs, midlegs, and hindlegs. Each leg is jointed and is divided into three sections: 1) the femur (we have a femur bone in our thighs), 2) the tibia (our shinbone is called the tibia), and 3) a claw-like foot called the tarsus.
Of course the most beloved part of the butterfly are those interesting wings! You’ll notice two sets of wings with two forewings in the front, and two hindwings in the back. Butterflies don’t flap their wings up and down like birds do. Instead, the muscle contractions in their thorax move the wings in a figure eight pattern. They’re made of thin layers of protein called chitin, and thousands of colourful, overlapping scales. Bright colors may be used to warn predators of their toxicity, or patterns can be used for camouflage. Some butterflies even have large ‘eye spots’ that mimic owl eyes to intimate predators. You’ll also notice lines, called veins, running from the base of the wing towards its outer edge. These veins give the wing membrane its strength. For children who are not sensitive, studying the wings of a butterfly under a microscope is fascinating.
3. Abdomen Butterfly Anatomy
The abdomen has our butterfly’s important organs. You’ll find their digestive tract to convert their food into the energy they need to run their bodies. Along the side are small holes, called spiracles, that they use for breathing. And a little further down, towards the end, are the butterfly’s reproductive organs. The abdomen is divided into 10 segments. If you look closely at the picture above, you’ll see the lines that divide them.
Free Butterfly Anatomy Poster and Worksheets
Sign up for our newsletter here or at the end of this post to download your Free Butterfly Anatomy Poster and Worksheets. You’ll find the link to our subscriber community page, which includes all our free Books and Willows learning resources, in your welcome letter and in every newsletter sent. Don’t forget to check out our Free Nature Poetry and Copywork page for the poem The Butterfly and the Bee, by William Lisle Bowles, to go along with your study!