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How the Firefly Could Help Us

Encouraged by school children, Indiana Governor Eric Holcomb signed Senate Bill 236 designating Pyractomena angulata, also known as "Say's Firefly", as the official state insect of Indiana. We will likely now proceed to kill it. Proactive decisions about outdoor lighting could mitigate our impact on the firefly and ourselves alike.

Also dubbed a lightning bug, the firefly is actually a beetle. The species embraced by Indiana has an amber glow, with the male flashing a rapid flicker every 3.5 seconds. Fireflies use that pattern to attract mates. With the increasing glow of artificial lights at night, the challenge of sticking out at night has become more complicated. While fireflies enthrall us on summer nights with their flash pattern, we're encroaching on their tool for survival.

Firefly pattern adapted from Museum of Science, Boston, flash chart.

Poor outdoor lighting is hurting us humans as well. The American Medical Association (CSAPH Report 2-A-16) notes blue-rich LED lights impinge on human health by affecting the circadian system. It seems every cell in your body has time-sensitive functions, with the clock set according to the wavelength of light. The blue, high-temperature light coincides with the peak sensitivity of the circadian system, hitting you where it hurts most.

What are we supposed to do about it? The AMA report recommends, "the use of 3000K or lower lighting for outdoor installations such as roadways. All LED lighting should be properly shielded to minimize glare and detrimental human and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods."

Given options, why choose what is known to be a more harmful light fixture? I have asked several entities about their light selection, receiving a range of responses. Here are some examples of public lighting issues in the region.

NIPSCO is replacing all of it's streetlights with LEDs, moving from the western edge of its territory toward the east. In an acknowledgment form NIPSCO offers communities an option to go with either its standard 4000K streetlight or a lower 3000K alternative. By default NIPSCO chooses the bluer version. Why knowingly default to the bluer option?

After several unanswered phone calls and emails to a NIPSCO Public Affairs Manager and to its lead LED scientist, I finally connected with a manager supporting western counties. He said the bluer light was selected after input from the community and scientists; the 4000K was preferred. He acknowledged there is known impact to the environment. The decision had been made; he dismissed the possibility of changing the default LED to a lower temperature even though the human health hazard of blue-rich LEDs is documented.

Map of NIPSCO territory.  Orange is electric service, which may include streetlights.

I'm getting more militant in my dark sky advocacy, for I equate that corporate response with the tobacco companies who denied second hand smoke was harmful to human health. Even when the science is known that a certain product is more harmful, they continue to promulgate the lesser product as the default standard.

Municipalities are responding in part. In February 2018, the City of New Buffalo, for example, selected 3000K LED fixtures for its downtown redevelopment. Meanwhile, dark skies advocate Larry Silvestri suggests NIPSCO customers Ogden Dunes, Portage, Michigan City, and Beverly Shores have chosen or are considering the alternative 3000K to the the bluer 4000K. I encourage more cities to challenge the NIPSCO standard.

Sometimes people notice poor lighting enough to raise their voices with effect. In the City of Mishawaka, apparently enough people disliked the egregious lighting of the new Beacon Parkway that the city utility has started to remove every other lamp post. On the down side, the poorly shielded lights that have been extricated will eventually show up later at some other site.

Mishawaka in process of removing light posts on Beacon Parkway.

St. Joseph County Engineer Jessica Clark and her department have done a good job with county lighting at several of its new roundabouts--Cleveland/Bittersweet, Auten/Ironwood, and Brick/Fir. When driving at night, notice how the LED fixtures are full cutoff, how the light sufficiently illuminates the roadway, and how you don't have glare in your eyes as you approach the intersection. Communications I've had with county staff have been promising as they ask questions about future projects and lighting options.

At the February 22 Mayor's Night Out in South Bend, Director of Public Works Eric Horvath suggested their new Main Street lights were 3000K (to be confirmed), and that they were interested in getting the lower temperature LED fixture in city streetlights. The city currently does not have a temperature standard for streetlighting. The power company AEP owns the majority of streetlights in the city, so the city can encourage AEP to adopt the less-blue version. A 3000K fixture can provide sufficient, comparable lumens as a 4000K fixture, as NIPSCO's dual offering would require.

Staff from South Bend Public Works Dept. discuss outdoor lighting fixtures at Mayor's Night Out.

In a conversation I later had with Mayor Pete Buttigieg, he asked thoughtful questions about differences between 3000K and 4000K fixtures, including how well each covers a given area, efficiency, cost difference, and visual appeal. I didn't record our conversation, but I recall he welcomed the less harmful 3000K option if it delivers the requisite lumens. I suggested the city follow the AMA recommendation, then tout it. They have Smart Streets and smart sewers, so have smart lights, too.

We talked briefly about the Lamp Post Lighting Project and the LED bulb included with it. A full cutoff LED fixture, available for an upcharge, is not included with the three sample lamp posts in the Mayor's Office, though four styles are offered in the city's literature.

As an aside, on the way out the door of host Dickinson Intermediate Fine Arts Academy, I also met a team of interns. I shared some information on solargraphs and we spoke of their securing a solargraph can at the City-County Building in downtown South Bend. That was just one more reason I enjoy and respect the city servants who staff the Mayor's Night Out. They were all doing community outreach after hours, keeping their commitment to residents on the night the city was flooding. It had been a long day for many of them, yet they showed up.

Back to the LED color issue, individuals are not off the hook. We, too, can select lights that are "soft white" as opposed to the "daylight" bulbs that are much bluer. Simply look on the label (see Primer on LED Packaging) when purchasing and choose 3000K or less. Frankly, I swapped out a bunch of old CFL and incandescent bulbs with 3000K LEDs, but the color inside was still harsh. I then tried 2700K bulbs purchased online, and the color is perfect. Try your own experiment to satisfy your needs, but I trust you'll find lower is better. Outdoors, change your LED lights like a Nobel laureate might.

In the book Ecological Consequences of Artificial Night Lighting, contributing author James E. Lloyd writes Chapter 14: Stray Light, Fireflies, and Fireflyers, in which he notes "the potential effects of stray light interfering with fireflies in their environments. These effects are exacerbated by the cumulative effects of other ecological insults; hope for the amelioration of these effects may lie in part in the universal appeal of these small beetles."

With the Pyractomena angulata now recognized as the Indiana state insect, perhaps more people will look for--and look out for--the pleasant little bug. If you do, share your findings. For more information on observing and recording fireflies, see

Firefly pattern adapted from Museum of Science, Boston, flash chart;

Image: Museum of Science, Boston

I hope the kids who encouraged Governor Holcomb to adopt a firefly as the state insect in 2018 see widespread progress to preserve that selection. Improvements in outdoor lighting are a doable step for the firefly's cause. Preserving the Say's Firefly will likely serve us humans as well.

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