Synchronizing Fireflies

FirefliesFireflies (or Lightning Bugs as we call them in some parts of the country) light up our lives!

Did you know that more than 19 kinds of fireflies live here in the Great Smoky Mountains National Park region? And, they are the only species in America that display a synchronized flashing light pattern.

 But you must watch fireflies when you can!  This year, the Elkmont Firefly Viewing event in Great Smoky Mountains National Park will take place from Tuesday, May 31st through Tuesday, June 7th. Go to www.recreation.gov for advance parking passes and more info about what to bring with you!  Because of the popularity of the synchronous firefly display, access to the Elkmont area is restricted after 5 p.m. in late May and early June to registered campers and those who park at the Sugarlands Visitor Center and ride a special shuttle trolley to Elkmont. Access to the Sugarlands parking lot and to the trolley during this period requires a parking pass, which must be obtained in advance through the website.

These beetles, officially referred to as “Photinu carolinus”, take from 1-2 years to mature, but amazingly their lifespan is only around 21 days. Peak season for the synchronous fireflies in the Park is normally from late May to mid-June.

While they are larvae, the fireflies feed on snails and small insects. During their life, they don’t eat. The light patterns are what they do to attract a firefly mate! Each species has its own flash pattern that helps them recognize each other. While most have a greenish-yellow light – one species flashes bluish. It is usually the males that fly around and do the flashing and the females stay put but respond with a flash. No one is sure why the fireflies flash synchronously. Maybe the boys are in a competition – they want to see who will flash first. Or maybe if they all flash at the same time, they will have a better chance of being noticed.

While the light show is usually the last two weeks of May and the first two weeks of June, the dates may vary from year to year. Scientists say it may depend on temperature and soil moisture.  A few insects start flashing, then more join in as the season progresses. The show may be harder to see on misty, moist evenings – and cool temperatures can also shut down the show.

 If you are lucky enough to attend, please remember:

  • Cover your flashlight with red or blue cellophane
  • Use your flashlight only when walking to your viewing spot
  • Point your flashlight at the ground
  • Turn off your flashlight when you find your viewing spot

You can also help protect the fireflies and their habitat:

  • Do not catch the fireflies
  • Stay on the trail at all times
  • Pack out all of your garbage

If you aren’t able to get access to Elkmont, there have been reports of being able to view fireflies in areas around the park, however, those areas do not have as adequate parking.