Tag Archives: Firefly Watch

World Firefly Day 2020: Hope Rising!

Since 2017, the Fireflyers International Network has been sponsoring World Firefly Day, held during the first weekend in July. In previous years, people all over the world have come together to joyfully celebrate the magic and the science of fireflies with festivals, talks, and other events taking place in Malaysia, Thailand, China, Belgium, Mexico, USA, and many other countries. More than mere insects, these luminous beings help keep us connected to Earth’s natural magic.

During 2020, the global coronavirus pandemic has profoundly disrupted our lives. It has taken away loved ones and livelihoods, spread grief and despair, and divided us from family and friends. We wake each day heavy-hearted, weighed down by the gravity of the news. To confront these dark times, we have chosen to center World Firefly Day 2020 around Hope Rising!

Icons of summer, harbingers of monsoons, for centuries these beloved insects have sparked joy and inspired wonder for people all over the world. During these dark times, fireflies also remind us of the great resilience of the natural world, so full of life! So we celebrate them this year as tiny beacons of hope, sparkling lights carrying a promise that humanity will emerge into a brighter future.

Because festivals and gatherings have been cancelled, World Firefly Day 2020 will be celebrated virtually with videos, music, and presentations posted on FIN’s Youtube channel and on FIN Facebook. If you can’t enjoy real fireflies this year, please join our virtual celebration by sharing your firefly stories, poems, photos and artwork with your fellow firefly enthusiasts on FIN Facebook!

Flickr: Steven David Johnson
Flickr: Steven David Johnshon

When everything has been turned topsy-turvy, tuning in to nature’s rhythms can provide comfort and consolation. With summer camps cancelled and vacations vanished, many of us are preparing to spend this summer at home. So how about a staycation with fireflies? Step out into the night and look for fireflies in your backyard or local park. Camp out with the kids & catch some fireflies in a jar (remember to keep them happy with an apple slice or some damp paper towel).  Grab a penlight and practice some lightningbug linguistics. Join the citizen scientists over at Firefly Watch and help us keep track of long-term trends in your local firefly populations.

Stay safe, be well, find joy – we will recover, we will rise up & shine brightly once again!

What’s behind a fabulous firefly season?

Sometimes our summer nights are ablaze with silent sparks, while other years we might barely see a flash in the exact same spot. What gives? A recent study provides some insight into what drives these fluctuations, and it reminds us to take the long view.

These flashy adults are the just reward for having survived many months during their larval stage.

Keep in mind that the flashy adult represents just a tiny fraction of a firefly’s life cycle. Before that, they spent up to two years living underground in a juvenile larval stage. During this time they are eating machines, growing steadily as long as they have access to their prey – mainly earthworms, snails, and slugs. Only if they manage to survive predators, competitors and climatic conditions will they eventually emerge into an adult firefly.

Fireflies spend many months being very cute in this larval stage

The study:

Firefly Watch observations gave info on firefly abundance across all species

What was their goal? Tracy Evans and her colleagues (see full citation below) decided to see if they could predict changes in adult firefly abundance across different U.S. locations using data on weather conditions during juvenile development.

What did they do? They took data gathered by citizen scientists who participated in Firefly Watch between 2008 and 2016 (only total firefly counts were used in this study). They combined this with information from NOAA on monthly temperature, precipitation (rain & snowfall) and soil moisture for each location.

Weather conditions before adult emergence had an impact on firefly abundance.

What did they discover? Weather conditions during juvenile development had a small but significant effect on the abundance of adult fireflies. In particular, adult abundance increased when soil moisture was high during development, and decreased when soil moisture was low. Precipitation also mattered: for 20 months before adult emergence, both too much and too little precipitation reduced firefly abundance. Very high maximum temperatures during the previous winter and spring reduced abundance.

What does this mean? Of course different firefly species will have different requirements, but this study reveals some interesting general patterns. Fireflies seem to thrive when there’s sufficient soil moisture, and when there’s just enough precipitation – not too much and not too little during their juvenile stages.

Citation (warning, paywall!): Evans, Tracy R. ; Salvatore, Donald ; Van De Pol, Martijn ; Musters, C. J. M. 2019. Adult firefly abundance is linked to weather during the larval stage in the previous year. Ecological Entomology, 44: 265-273.