Citizen Science

The Wonder of Fireflies

August 5, 2014

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Fireflies in the Catskills. © s58y / Flickr

What is Firefly Watch?

Do you have fond memories of fireflies? Does it seem like there are fewer fireflies around than when you were a kid? You might be noticing a trend — and you can help scientists track these special insects.

Firefly Watch is a project dedicated to finding out more about firefly populations and they need your help.

By submitting information about firefly sightings, you will help scientists answer important questions about fireflies  and assess the need for conservation.

How are species distributed across the USA? Are their numbers dwindling over time? Are populations moving?

Why is it important?

Fireflies are special. They stand out as one of few bioluminescent critters that live on land.

“I realized that people really care about fireflies,” says Don Salvatore, Firefly Watch coordinator and science educator at the Museum of Science in Boston. “They have had wonderful experiences watching and chasing fireflies when they were young and now they want to share those experiences with their own children.”

“People today connect with nature in so few ways, that if we can nurture their love for fireflies, they may take a greater interest in preserving the natural world,” he adds.

And fireflies seem to be disappearing.

“Many people have come up to me at the museum and asked what is happening to fireflies.  They used to see them all the time when they were kids but haven’t seen any in many years,” Salvatore explains.

That’s why the museum created Firefly Watch. They realized that science needs more data on fireflies and hope that with enough citizen science help they will be able to understand the cause of the decline and find a way to address the problem.

“Until that time, I hope that as many people as possible are turned on to the real magic of fireflies through Firefly Watch,” Salvatore says.

I can hardly think of a more delightful way to contribute to science than by sitting outside with family, watching fireflies, and recording observations.

And there’s more! Firefly Watch has an amazing website that will teach you all about fireflies.

“People join the project knowing next to nothing about fireflies – they fly at night and they flash.  That is it,” says Salvatore.

Did you know that you can often tell the species of a firefly by its color and blinking pattern? That female fireflies usually rest on grass and signal while males fly around signalling and watching for females? Or that they have poisonous blood as protection from predators?

Firefly Watch has a great virtual habitat that teaches you about fireflies and lets you practice your identification skills.

They share all of the data collected with the public so that scientists, educators, conservationists, and the public can use it. You can even see your observations recorded on the Firefly Watch map.

How do you get involved?

Sign-up and find a place to watch for fireflies!

It could be your yard or a nearby park. Once you’ve found a spot, it takes just ten minutes each week to watch. Then record your observations and submit them to Firefly Watch.

If you have any trouble, there are FAQs, field tips, and a discussion forum to help you out.

For those who want to do more, there’s a toolkit with suggestions for expanding your impact. For instance you might recruit more volunteers, give a presentation on fireflies, or lead a firefly hike.

“Most (not all) fireflies are creatures of the summer.  So the best time, the only time, to do Firefly Watch is summer nights when fireflies are active,” Salvatore explains.

This is an activity for people of all ages. Over 5,000 people have participated from about 40 states and 6 provinces. Sadly for West Coast dwellers, there are no flashing fireflies West of the Rockies (but for bioluminescence fans, there are glow worms & daytime fireflies).

So get outside and start watching for fireflies, lightning bugs, or whatever name is preferred in your area!

Is there a citizen science project that you think deserves more attention? Contact Lisa Feldkamp, lfeldkamp[at] with information about the project or leave a comment below with a link.

Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of the Nature Conservancy.

Lisa Feldkamp

Lisa loves all things citizen science and enjoys learning about everything that goes on four legs, two wings or fins - she even finds six and eight-legged critters fascinating at a safe distance. She has a PhD in Classical Literature and Languages from the University of Wisconsin - Madison and enjoys reading Greek and Roman literature or talking about mythology in her spare time. More from Lisa

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  1. Fireflies are one of many creatures that are mostly all on the wetter side of the 100th meridian of longitude….the rough dividing line through the midwest that has average precip > evap to the east and precip < evap to the west. There is a big change in species diversity there in the middle of the country. I suspect that whole "line" of change is moving east (??) as climate change is upon us (just a guess associated with the move upslope and up-latitude of distributions).

  2. I thought that the poison used to kill mosquitos was killing them. Is that not true? Mass sprayings in Houston appeared to kill not only the mosquitos but the fireflies.

    1. Hi Christine, That’s a great question. I don’t think that there is enough evidence at this point to say for sure that is the cause of the decline (or the only cause). It is a possibility. FireflyWatch hopes to provide the evidence that will answer this question.

  3. I visit my hometown South Bend, Indiana, late June-early July every year. Last year lightning bugs were pretty rare…but this time around they were noticeable more prevalent. Gave me hope!


  4. I visit my hometown South Bend, Indiana, every year, late June-early July. Last year lightning bugs were pretty rare, but this year they were fairly plentiful. Gave me hope!


  5. We have lived here 50 miles from the coast and just started seeing fireflies this summer, at night of course. They were buzzing around the porch, then I started seeing some of them in my hummingbird feeder dead, do you think that attracted?

  6. Our back yard (grown without pesticides) has two good sized areas we turned into wildlife support mini-meadows with lots of native grasses, flowers, and seeds. We continue to have lots of fireflies over them and over the adjacent lawn each summer (also frogs, an occasional snake, and lots of different kinds of birds and insects, including bumblebees and an occasional honey bee). Plus an occasional visit from a bear, red fox, grey fox, or bobcat.

    We recommend backyard mini meadows… better than TV and it feels good to provide help to other species.

  7. We have seen fireflies in our neighborhood this summer – a quiet residential place with many people who have flowers and vegetable gardens. It was very dry most of the summer and is now wet, and we didn’t count them but were very aware that they were around here flashing. I hope you can post what they look like during the day, as I have no idea about that. Do they have an official name? Owatonna is south of the Twin Cities and only an hour’s drive to Iowa.

  8. There were a few fireflies here in a woodland development, at 3,000 ft. in WNC in June. They were mostly in the opened areas of tall grassland. After June, they disappeared.

  9. it would be helpful to republish this article late next spring. Here in NE PA, fireflies appear the second week of June and are mostly gone by mid-July – almost the same schedule as Japanese beetles.

    1. Thank you for the suggestion! I think that I will write about Clemson’s project in the spring and link back to this post to remind people about the options for reporting.

  10. We have seen many fireflies at dusk all summer. We live on the shoreline of an 18 lake about 10 miles northwest of St. Francisville, LA. The shallow lake is full of fish, aquatic plants, frogs, some snakes, etc., that attract many species of wading birds. Three years ago the lake nearly dried up due to a long summer drought. The area is heavily forested around the perimeter of the lake.

  11. I live adjacent to Marsh Creek State Park in SE PA, about 20 miles Northwest of Philadelphia. The fireflies typically appear here around late June, peak in early July and are usually gone by the mid to end of July. At peak, there are typically thousands flying around on any given night (unless it’s raining). I also noticed that they seem to peak in activity in the evening (pre-midnight) hours then decrease as the night continues into the early morning hours.

  12. We used to see fireflies in abundance every summer when I was growing up in the suburbs of Chicago. I was in the suburbs of Chicago for 2 years in the summers of 2011 and 2012 and I noticed that sightings were less frequent (fewer nights AND fewer flashes) than I remembered them from 1950 to 1975.

    My husband grew up in Peoria, in central Illinois, and he also remembers seeing abundant fireflies in the bushes and in his back yard. On our recent trips to Peoria, we saw very few (hardly any!) fireflies there also!

    We have lived in Houston TX for the last 39 years and we have NEVER seen them at night in Houston! I presumed they didn’t live in Texas, until we noticed them (not an abundance of them, however) on occasional trips to the Texas Hill Country (west of I-35 from about Waco to San Antonio)–perhaps it IS the regular mosquito pesticide spraying in our neighborhoods! Certainly there is more of that now in Houston than we had in the suburbs of Chicago or in Peoria, Illinois, when we were growing up!

  13. I grew up in Florida on the east coast and every summer fireflies were plentiful. We chased them as children, put them in jars to light a dark room (let them go) and it is one of my fondest memories. i still live in Florida and sadly, the only place I have seen fireflies are in some state parks, well removed from towns/cities, where mosquito control is banned. I also see fewer butterflies….No matter what the politically correct answer may be, I think there is no doubt that mosquito control, along with agricultural insecticides are impacting our beneficial insects. Certainly, evidence is showing that the nictinoids are having a devastating effect. And the Monsanto produced Round-up (glycophosphate) used by large farms is impacting the Monarch population along its migratory route. Of course, Round-up is used by homeowners, etc. not just agriculture. If one wants bees, butterflies and other beneficial insects in you yard or garden, don’t use it or, at least, use it specifically and sparingly.

  14. As Firefly Watch becomes more popular and gets more observations (remember – they accept reports that no fireflies were seen, especially in areas where you remember seeing them before, during the season/time of day that you would expect to see them), I would love to see them overlay maps of where fireflies are most abundant/where they have disappeared with maps of where mosquito spraying is most prevalent. If there is a relationship, that would be a great way to show it and, I think, to generate more action on the issue.

  15. Fortunately I have a heavily wooded backyard that provides a home to many native species, including lightning bugs. I’ve read about the decline over the years but haven’t seen it in these parts(piedmont of SC). They don’t spray for mosquitoes here which may help. I’ve also read that they don’t like too much artificial light, which is growing in abundance as more rural areas become developed.

  16. I have hundreds of fireflies in my front yard every summer. It is cool, quite a few trees and tends to stay a bit damp. I had heard before that fireflies are disappearing, but you would not know it where I live. I did not know there was firefly watching but find it interesting. I, too, used to catch fireflies when I was a child and am blessed to have the now.

  17. I am a fortunate one that have a firefly habitat teaming in the park behind me and my backyard, right now first week of june thousands upon thousands of fireflies rise from the grasses and move to the circle of trees in my field. There is when the magic starts, they must have lots of love amongst them because it is wonderful to watch them light up light Christmas trees. It is such a wonder. I did also read that if Fireflies habitat is destroyed then they do not relocate they simply just die out. So lets show our fireflies all our love. I am so thankful they get together at my house each year at this magical time. Gina

    1. Hi Gina, That does sound magical! Thank you for keeping your firefly habitat intact!