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Thomas Say and His Firefly

Discover the scientist—and the firefly—that lit up Indiana.

What do a glowing insect and a pioneering scientist have in common? Explore the story of Thomas Say, his work in New Harmony, and the firefly that now shines as Indiana's state insect.

Meet Thomas Say

Thomas Say was a famous scientist who came to New Harmony in 1826 as part of the "Boatload of Knowledge." Before that, he lived in Philadelphia, where he worked at the American Philosophical Society and taught at the University of Pennsylvania.

Say loved studying the natural world. He wrote American Entomology, the first book about insects published in the United States. Later, he wrote American Conchology, a book about shells found in North America. His wife, Lucy Sistare Say, helped bring his work to life by drawing and coloring most of the illustrations in the book.

Say spent the rest of his life in New Harmony and died in 1834. Today, he is buried on the Owen Mansion property. You can see his tomb from outside the property's fence on the corner of Main and Granary Streets. 

Because of his important work, Say is often called the "Father of North American Entomology" (the study of insects) and the "Father of American Zoology" (the study of animals).

While living in New Harmony in 1826, Say studied and described a special firefly that now carries his name: Say's Firefly (Pyractomena angulata). It is native to Indiana, making it a perfect symbol for the state. 

How Say's Firefly Became Indiana's State Insect

Indiana didn't always have a state insect. In fact, it was one of the last states without one!

Students helped change that. Schools across Indiana, including some in Posey County, took on the challenge as a civics project. They learned how laws are made by writing letters, gathering signatures, and asking leaders to support their idea.

One group of second-grade students worked on this project for four years! They collected hundreds of signatures, wrote over 800 letters, and supported several bills in the Indiana General Assembly.

Many people and groups helped, including teachers, scientists at Purdue University, community members in New Harmony, and state leaders.

Finally, on March 23, 2018, Governor Eric Holcomb signed the law-making Say's Firefly the official state insect of Indiana.

Why a firefly? Scientists say insects are very important to our environment. They help pollinate plants, recycle nutrients, and keep ecosystems balanced. Fireflies are also easy to see, harmless to people, and bring a sense of wonder on summer nights. 

What Makes Fireflies Special?

Fireflies are more than just fun to watch—they play an important role in nature.

  • They help improve soil by loosening it.
  • As larvae (young fireflies), they eat lots of other small creatures, helping keep ecosystems balanced.
  • They are food for animals like frogs, spiders, and birds.

Fireflies are also called lightning bugs, but they are not flies or bugs—they are actually beetles!

There are more than 1,900 kinds of fireflies around the world and about 170 in North America. Many live in the eastern United States, in places like fields, forests, wetlands, and marshes.

Why Do Fireflies Glow?

Fireflies glow to communicate—especially to find mates.

You'll often see males flying and flashing at dusk. Females usually stay in the grass and flash back if they are interested. Each species has its own special flashing pattern, like a secret code.

Their glow comes from a chemical reaction inside their bodies called bioluminescence. This reaction creates light without heat—kind of like a tiny natural light bulb!

Fireflies can glow in different colors, including yellow, green, and amber. These colors and patterns help them recognize others of their own kind. 

Fireflies Are in Trouble

Today, fireflies are facing challenges in many places.

Some of the biggest threats include:

  • Habitat loss (when fields, forests, and wetlands disappear)
  • Light pollution (too much artificial light at night makes it hard for fireflies to see each other's signals)
  • Pesticides (chemicals that can harm insects and the places they live)

When fireflies lose their habitats or can't communicate, it becomes harder for them to survive.

How You Can Help Fireflies

The good news? There are simple ways you can help protect fireflies:

  • Turn off outdoor lights when you can
  • Plant native plants and let parts of your yard grow naturally
  • Avoid using pesticides
  • Leave some leaves, logs, or natural spaces for fireflies to live
  • Visit and protect natural places like wetlands and wooded areas

Try this:

Spend time outside on a summer evening and watch for fireflies. The more we notice and appreciate them, the more we help protect them.

Fireflies in Indiana

Indiana is home to about 43 kinds of fireflies. Some flash, and some do not (these are called "dark fireflies").

Flashing fireflies in Indiana are grouped into three main types:

  • Photinus (yellow light)
  • Photuris (green light)
  • Pyractomena (amber light, like Say's Firefly)

Meet Say's Firefly

Say's Firefly is one of the first fireflies to appear each year in Indiana. You might see it from early May through mid-July.

It usually lives near wetlands and wooded areas. Unlike some species, you may only spot one or two at a time as they fly high through the trees.

Its flash is quick and flickering—about one second long—with several fast pulses. Then it pauses for a few seconds before flashing again.

If you look closely on a warm summer night, you might just spot this special firefly—the one named for Thomas Say himself.