A Firefly Talk With the Smokies Bug Master

A Great Smoky Mountains National Park entomologist since 1997, Becky Nichols knows a lot about the park’s nearly 10,000 insect species, but perhaps the most celebrated of the six-legged creatures is the synchronous firefly. The simultaneous flashes of light males emit from the trees during mating season draw crowds to the park each year, with stiff competition for tickets. It’s Nichols’ job to predict when the show will likely take place, and to help those attending better understand the mysteries of one of the park’s standout insects. 

When did you first realize that you wanted to become an entomologist?

When I was a little kid, I wasn’t that into bugs. I grew up in a rural area, and we always went camping and stuff, but I didn’t have a particular interest in insects. But when I took an entomology course in college it kind of changed things for me. Just looking under a microscope and making a collection and seeing the diversity that I never knew was there until I really started looking and learned about all the different types of adaptations and forms that insects have—it was just really interesting to me. 

Synchronous fireflies are probably the most well-known insect in the Smokies. What is it about them that fascinates people so much? That fascinates you?

I myself did not grow up in an area where there were fireflies, up in the northwest. When I first moved South I started seeing fireflies, and they’re just really an interesting, magical kind of thing to see. I think a lot of people that come here to see the synchronous fireflies have experienced them as they were growing up, so maybe it reminds them of their childhood, some nice memories. It’s amazing to see the reaction of people. You can be standing on a trail with a crowd of people looking at this display, and they’re not making any noises. When you get a group of people together and they’re not saying anything, just enjoying the experience, it’s pretty amazing. They’re just mesmerized by the display. 

The firefly viewing at Elkmont is one of the Smokies’ biggest annual events. How do you predict what the peak dates will be from year to year? 

Basically I’m calculating the difference between the mean temperature, the high and low, and a base temperature each day starting on March 1. When you accumulate those, we know the set number that Photinus carolinus (the synchronous firefly) needs to reach before it will go into the pupal stage. By doing this I can gauge where we are as compared to last year, the year before. Are we way ahead or way behind compared to past years? What started us doing this is in 2012 they were two weeks early because it was a really warm spring, and it really caught us by surprise. All of our people going out there on the trollies were not seeing very much, so we figured we better take a closer look at this and try to predict closer when they’re going to emerge. 

Other than fireflies, what do you see as some of the most notable insects of the Smokies? Do you have a favorite? 

There’s so many species. There’s close to 10,000 species of insects here in the park that we’ve tabulated. I do have a number of species that I really enjoy seeing every year. A lot of them are aquatic insects because I spend a lot of time working in streams, doing the aquatic insect monitoring every summer. There are some species of mayflies that I guess you could say are favorites of mine. One is called an armored mayfly, and it’s pretty rare, so it’s really interesting to see it. It’s only in the western part of the park, and I feel lucky when I find it. I guess that part of it is like a treasure hunt. If I find it, I feel like the water quality is doing well in the stream.