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PrintTime for Fireflies!
The light flashes on and off, over and over, as it searches for friends in the shrubs and grassy areas of the yard. June evenings are for playing outdoors and perhaps you remember playing spotlight tag in the dark when you were a kid.
Fireflies play a similar game, and June evenings are a perfect time to watch them. The twinkly lights dancing over fields are created by male fireflies. They flash a distinct pattern of lights in hopes that a female of the same species will notice them. The females wait in the plants, close to the ground and flash a reply.
Fireflies, also called lightning bugs, are actually not flies or bugs, but beetles, and beetle specialists can recognize different species by the length and duration of the flashes and pauses performed by the males. The greenish glow these insects create occurs in special organs in their abdomen.
Firefly larvae usually live two years underground and then pupate into an adult. From there, it’s a race to mate and lay eggs, and the average adult lives only about two weeks.
Fireflies eat other insects, snails and slugs, but some clever females have a trick under their wing. They have the ability to mimic the response flashes of firefly species other than their own. When the unsuspecting male swoops down to greet the female, she captures and eats him!
Did you know?
The firefly is the state insect of Pennsylvania. At one point, Indiana considered making it the state's insect, but the legislature never put the measure to a vote.
Family Activities
Be a Beetle Scientist!
Here's a way for you to learn about your local fireflies, also known as lighting bugs.
Do different species flash at different times of night?
- Gently catch and observe fireflies in a jar. Punch air holes in your container for air.
- Observe the flashing in the jar. Count the number of flashes, how long they last and the time between flashes. Do this for five minutes. Record your data.
- Return to your capture site and gently release your insects. Wait one hour and return to your site. Recapture fireflies and repeat your observations. If you notice a different flashing sequence, you probably have a different species!
Play Firefly Tag!
In this game, players pretend to be two different species of firefly known by their Latin names as Pyralis and Consimilis. Although they look alike, their flash pattern is different.
The male Pyralis flashes a single flash during rising flight movement. It looks like the letter "J." The female responds with a single stationary flash.
The male Consimilis flashes a series of short, fast flashes as it hovers in one place. The female answers with two long flashes followed by a long pause.
Each person in this game needs a small flashlight. Practice the flashes of male and female Pyralis and Consimilis together, so everyone can see what they look like.
Next give every player a card that says one of the following: Male Pyralis, Female Pyralis, Male Consimilis or Female Consimilis. Be sure to hand out nearly equal number of male and female cards of each species.
Stand in a wide circle in the dark, with plenty of space between you and your friends. When everyone is ready, flash your lights according to which species and sex of firefly you are. Don’t aim your lights in anyone’s face!
Remember, females don’t fly much, so males should walk across the circle to the “female” they think has the right response flash. Use your flashlights to check your cards and see if you paired up correctly!
