Where have all the lightning bugs gone?

I’m not an entomologist—not even of the armchair variety.  Nor am I a conservationist, or a meteorologist.  My schooling in ecology does not extend beyond a single graduate-level course that dealt with how urban development disrupts various animals’ habitat and migration patterns.  And it is that course content that I can apply against a backdrop of deductive reasoning, for which I’m fairly adept, since I do it with nearly every article.  And this entire analysis hearkens to my title question: what has happened to all the lightning bugs?  Let me deduce what I can.

Lightning bugs are much rarer in urban American than previously

Regional vernacular might prompt a person to use the alternate name firefly or glowworm, the latter of which I’ll confess I thought was an entirely different family of insects.  But these are just three different terms to describe more or less the same thing: about 2,000 different species of beetles best known for the evening glow.  Regardless of the name, across most temperate and subtropical regions of the US, the common eastern firefly (Photinus pyralis) helped augur a number of incidents that would make a kid happy: the end of the school year, the beginning of vacation, and those long drawn-own sunsets emblematic of Midsummer, which is when lightning bugs amplify their mating bioluminescence.  It doesn’t hurt that lightning bugs, in contrast to most insects, aren’t vexatious to humans in the least: they don’t bite or barb or sting or seep toxins into the skin.  They’re comparatively slow, generally unfearful (drifting in the evening air and flaunting their photons to paramours), and the green glow is pleasant—sometimes beautiful.  Sharply contrasted without about 99% of insects, lightning bugs evoke positive connotations; they belong to the small but enviable strata that also includes butterflies, love bugs, ladybugs, and maybe certain grasshoppers or bees or mantises (and even some of these are debatable).  In contrast with such mammalian cultural indicators of beauty as pandas, tigers, wolves, and elephants, lightning bugs are charismatic microfauna, a term I only invented as a contrast to megafauna.  While the megafauna are abundant—it includes almost anything that is either furry, big-eyed, or vaguely humanlike in movements—microfauna in general and insects in particular rarely qualify because they lack these same qualities.  (Okay, some insects are indeed big-eyed in proportion to their bodies, but these eyes aren’t expressive like those of a cat…and how many eyes do the insects have?)

In summation, lightning bugs rank near the top of a very short list of insects that people don’t reflexively swat away or stomp on.  People actually like them.  So it’s not surprising that the little critters are riding a wave of escalating cultural concern that we just don’t see them as often as we used to.  After spending a good part of June and early July nights as a child chasing lightning bugs, letting them curiously crawl on my hands, and maybe even bottling them up to keep as a 12-hour pet (be sure to put air holes in the top of the jar!), I grew indifferent toward them as a teen and adult.  During college and subsequent years, June elicited more anxiety than fun, as I tried to secure good short-term employment.  In fact, it wasn’t until a summer vacation to the Great Plains in 2016 (a summer I documented multiple times through various blog articles) that I became reacquainted with lightning bugs, realizing how little I had seen them as an adult.

Specifically, I visited an old college friend in Vermillion, South Dakota in July.

This small city of less than 12,000 people—entirely tied to the University of South Dakota’s flagship campus—isn’t necessarily remote by South Dakota standards.  Though much of the Mount Rushmore State is virtually empty, this southeastern corner is about a forty-minute southward drive to the reasonably large city of Sioux City, Iowa; a little over an hour’s drive to the north is Sioux Falls, the largest city in that state whose primary public university calls Vermillion home.  On an evening walk after a dinner along Vermillion’s Main Street (pictured above), we ventured south to the park overlooking the Vermillion River, a tributary of the Missouri River several miles further south of the city.

There, in that riverfront park, I saw the highest density of lightning bugs I ever remember seeing in my life.  They were everywhere; a 100-square-foot patch of land probably hosted several hundred.  I had seen nothing like it, even from my childhood memories when lightning bugs were prevalent.  And it made me realize that these innocuous harbingers of summer heat and humidity almost seemed like a novelty, at least in the urban settings where I had lived.  It was all those lightning bugs that prompted me to take the photo below; though I’m not skilled to adjust the shutter speed long enough to capture a single one of them, at least this reveals the evening conditions that allowed them to flourish.

Was Vermillion’s comparative isolation the reason they seemed to flourish?  Sure, it’s not a big city, but it’s still fundamentally a small urban area, and one could only imagine the concentrations of lightning bugs if I were to travel fifty miles to the northwest, in a part of South Dakota where urbanized areas are few and far between.

Now I’ll skip forward several years and return to a massive conurbation: specifically the northern Virginia suburbs of Washington DC, where schools like this one (Gunston Middle) area a dime a dozen.

Gunston Middle was the trailhead for my firefly adventure; I continued north from there.  All of the subsequent photos come from a patch of land no greater than half of a square mile, taken between 8:30 and 9:00pm just a few days after the longest day of the year.  Here’s a map that loosely frames my little trek in search of urban lightning bugs.

Screenshot

I’ve covered the Arlington Ridge neighborhood in Arlington County a couple times in recent years.  Perched atop a ridge line close to the county’s boundary with the City of Alexandria, the steep grade change makes many portions difficult to develop, so the County purchased the land to serve as parks that largely encircle homes atop the ridge.  Given their high elevation (and views), proximity to amenities, and the parklike setting, Arlington Ridge homes are generally high-value and prestigious.

My “safari” used James W. Haley Park as the primary backdrop, as visible in the middle of the above map.  The purple arrows loosely capture the direction I traveled, first northward (uphill) then back southward (downhill).  The park itself spreads across some of steepest slopes in the area and is mostly unimproved: a hillside forest with a few trails running through it.  Here’s what it looks like.

Urban park at dusk in midsummer - perfect habitat for lightning bugs
Urban park at dusk in midsummer - perfect habitat for lightning bugs

And yes, this area was dense with lightning bugs.  Not Vermillion South Dakota levels of density, but close enough to what I remember growing up.  Also much denser than Gunston Middle School just a few hundred feet away, where the visible glow of lightning bugs was sparse at best.  What creates this huge distinction?

The book Road Ecology (2003) by Richard T. T. Forman (et al) scrutinizes urban-rural interfaces and their effects on wildlife feeding or migration patterns.  It’s hard to imagine James W. Haley Park qualifying as “rural” or “forested” given its modest size; a fully urbanized neighborhood exists immediately to the north and south.

Flanked by two schools—Oakridge Elementary (in the above photo) sits atop the hill to the north—this park may not be big enough to serve as a destination, but it gets plenty of foot traffic.  Students no doubt cut through and climb the Arlington Ridge hill on a regular basis.  Woodsy and unimproved though it may be, it has all the trappings of an urbanized park space in 2024, including intermittent litter and even some graffiti on the trees, seen here:

Urban park at dusk in midsummer - perfect habitat for lightning bugs

Who spraypaints a tree?!

At this location, I’m in the middle of the park, halfway up the hill, yet still no more than 150 feet from the edge of the woods.  And the lightning bug density was thicker than anywhere else in the park.  I had picked the optimal time of summer, at the perfect dusky point in the evening, and nothing here remotely indicated that lightning bugs were failing to thrive.  Once again, it wasn’t as dense as I remember in South Dakota, but it was every bit as dense as growing up.  And considering that this park is only five acres, mostly surrounded by median-density suburban development, the lightning bugs clearly can still easily function in a tiny oasis within a huge concrete jungle.

Continuing up the hill to the northern edge of James W. Haley Park, the area adjacent to Oakridge Elementary offers the one portion that receives regular maintenance: featuring a turf lawn, some charcoal grill devices, and apparently a gazebo (that I don’t recall seeing).  This portion of the park is probably no more than a half-acre in size, and the present of lightning bugs thinned out considerably but not completely.

More noticeable were the conditions once I left the park and returned to the Arlington Ridge neighborhood through one of the dead-end streets visible at the very northern edge of the cropped Google Map featured earlier in this article.

The upper-middle income neighborhood features well-maintained lawns and landscaping on every one of the eighth-of-an-acre properties.  And lightning bugs are basically absent.  The abundance of abiotic, waterless, impervious pavement is hardly alluring; turf grass lawns aren’t likely much better.  Because many homeowners liberally apply pesticides and weed removal to maintain a pristine, unnaturally homogenous herbaceous coverage through their curated lawns, it is reasonable to conclude that most species will find such non-diversity unattractive when compared to the natural occurring biodiversity in a much smaller patch of unmanaged forest like James W. Haley Park nearby.

But is that the clincher?  Are lightning bugs repelled by pavement and turf grass?  Distant memory is hardly the best rebuttal evidence, but my recollection of a big back yard of turf grass is that it was still filled with lightning bugs—at the level of the heart of James W. Haley Park.  But these nice suburban lawns seem to claim few or no lightning bugs whatsoever.  Are modern fertilizers and pest control measures more antagonistic to insect populations than they were in the 1980s and 1990s?  Are people’s yards even less biodiverse than they were back then, thanks to more aggressive and sophisticated lawn care solutions (mostly chemical)?

Maybe.  But my return walk down the hill helped sharpen my deductive logic.

Along a dark urban street at dusk - still a good habitat for lightning bugs

I walked down Arlington Ridge Road, the curvilinear collector road that forms the eastern edge of James W. Haley Park, the property of Gunston Middle School, and Gunston Park (an almost completely manicured park consisting primarily of tennis courts and soccer fields that partly serve the adjacent middle school).  Arlington Ridge Road’s sinuousness helps offset the steep slope for vehicles coming down from the ridge, but they still speed.  Road Ecology speculates that many insect and mammal populations are attracted to the edges of roads because the sharp difference in micro-ecologies: whether turf grass or forest, the impervious domain differs enough from the human (pervious domain) to aid in their travel and offer subtle differences in herbaceous plants or tree growth.  Opportunistic grazers can capitalize on these differences.  They also can feast on human food thrown from windows of cars.  And, of course, the roads are an ecological double-edged sword: many ground mammals get run over by cars (often unwittingly by the motorists), and no motorist can hope to control the number of insects squashed by their windshields.

Does this hazardous condition affect lightning bugs?  Maybe, but they sure don’t seem fazed.  Right along Arlington Ridge Road, with James W. Haley Park on one side, the critters were moderately thick—not as much as the heart of the park, but much more than any of the suburban lawns.  One factor I noticed: street lights on this segment of Arlington Ridge Road were sparse, and they were absent on the west side (with the park).  And here, the lightning bugs were most abundant.

Continuing southward on Arlington Ridge, to the point that the park ended and Gunston Middle School property began, the lightning bugs were once again scarce.  Not a single one visible at Gunston Park, to the south of the Middle School.

Is it any surprise?  By this point it is a little after 9:00pm, well past sunset, yet look how bright everything is: stadium-level lighting at those tennis courts and soccer fields.  Contrast this with the conditions 200 feet to the north, along Arlington Ridge Road, where streetlights are absent on the west side of the road—and lots of lightning bugs.  The insects aren’t repelled by the occasional car headlights (or their lethal windshield)—but a constant level of illumination is like kryptonite.  (No wonder lightning bugs don’t seem to fall victim to the notorious glowing blue bug zapper.) Road Ecology ascribes this to various nuisances—noise, odors, vibrations, or lighting in this case—contrasting infrequent disturbances (like headlights, to which animals can adapt) with repeated disturbances, which fundamentally alter and disrupt essential, life-sustaining behavior patterns.

In the end, my deductive reasoning largely aligns with the www.firefly.org article I cited near the beginning: lawn care hasn’t changed that greatly in the last 20-30 years.  While I’m sure there are spicier concoctions for fending off certain weeds or grass-eating pests, the growing awareness of toxicity and the increasing public favor for natural yards suggest to me that the conditions of the average suburban lawn may slowly become more favorable to lightning bugs, rather than less.

By contrast, urban and suburban America have grown increasingly enamored with “good” lighting, which means as much of it as possible.  Aside from a few carefully positioned (and rarely used) floodlights, my back yard growing up was mostly engulfed in darkness.  Streetlights in my cost-cutting City of Indianapolis often only stood at intersections, so the mid-block of a long street was pitch black.  But the push over the last twenty years—out of the interest of crime prevention and traffic safety—seems to favor an aggregate growth in street illumination, using more efficient bulbs with carefully controlled luminesce, but brighter overall.  Arlington Ridge Road was the biggest revelation; the lightning bugs had no problem dwelling near a busy concrete road, as long as the streetlights were sparse.  And, the farther into James W. Haley Park I went, far from the artificial lighting keeping summer sports chugging along at those two school properties, the more visible these charismatic microfauna became.

Lightning bugs are much rarer in urban American than previously

Lightning bugs used to be ubiquitous in American suburban settings; now they aren’t.  The increased illumination in medium density urban settings interferes with their ability to communicate and find mates, dwindling their populations.  Meanwhile, an inherently sparse concentration of lightning bugs can render their bioluminescence pointless, if there are virtually no others of the same specie in the immediate area.  So it’s a downward spiral.  Frankly, our concern also reflects our own urban chauvinism: we mostly live in cityscapes and use those as our standard of judgment, forgetting how much land is completely unorganized.  Frankly, I don’t think we have reason to fear the overall demise of the common eastern firefly; far more of America’s land area resembles Vermillion than the expansive suburbs of Washington DC.  But I think we have to come to terms with the fact that our love for safely illuminated city streets will render lightning bugs non existent across most of our suburban lawns, school yards, play grounds, and soccer fields.

Though not endangered as a whole, the presence of the common eastern firefly in our brightly lit cities is depleted, probably permanently.  Except for kids who grow up in rural America or towns the size of Vermillion, a lightning bug encounter might be a real novelty.  Almost as rare as finding a Monarch butterfly these days—but that’s a topic for another article.

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22 thoughts on “Where have all the lightning bugs gone?

  1. Jerry

    As child in the 1950’s, my friends and I would capture as many lightning bugs as we could and place them in glass pickle jars (holes in the lids, as you suggested) to create natural lanterns. We’d then release them when bedtime came. What fun it was to see them up close!

    Reply
    1. AmericanDirt Post author

      Releasing them at bedtime is the more compassionate solution, given that they otherwise would rarely live through the night. Apparently children’s jars are usually lacking in the moisture levels they need to survive. It’s a relief to see that lightning bugs are still prolific in wooded areas, though it’s sad they aren’t a staple of suburban back yards anymore.

      Reply
    1. AmericanDirt Post author

      Good to hear. I didn’t think of them being that prevalent in the early AM–but then, how early is early? Do you walk through a mostly wooded area or an area with lots of manicured lawns?

      Reply
    2. Mike Janders

      my early morning walks are around 3:30 – 4:00 AM. I guess I’m in semi wooded area going around the IRT trail. There is a lot of dead wood around that trail which they like so u think that helps.

      Reply
      1. AmericanDirt Post author

        yeah, from what I can tell they really love dead wood. And darkness, but that goes without saying.

        Reply
    1. AmericanDirt Post author

      Excellent. Proximity to the water probably helps. I know the canal is pretty brightly lit, but a private residential street is probably a lot less.

      Reply
  2. Matt

    I think we (you’re definitely among a great number of people who wonder about this) just forget that when we were kids, we were having our experiences with lightning bugs far away from great numbers of moving cars, in the relative seclusion of suburbia. i never really thought about it till I read your posts. It’s the automobiles.

    Reply
    1. AmericanDirt Post author

      High intensity light definitely confuses their ability to send those romantic Morse code signals to their—ahem—boyfriends and girlfriends.

      Reply
  3. Jeffrey Jakucyk

    I can see the lighting hypothesis being a strong factor in the case of lightning bugs specifically, but it’s a small piece of an overall collapse in insect populations. Note how few bugs end up splattered on car windshields compared to 20-30 years ago. This is not due to improvements in automotive aerodynamics, the bugs just aren’t there to be hit anymore. Increased use of agricultural pesticides, further habitat destruction, and climate change seem to be the primary factors. The effect can be magnified in urbanized areas due to reduced in-migration of bugs from the hinterlands.

    Reply
    1. AmericanDirt Post author

      I have to admit I really didn’t notice a reduction in windshield splatter, but you could be right. Just something I never thought about. I also hadn’t really considered the depletion of lightning bug populations until that fateful visit to Vermillion, South Dakota, where I saw more in a single location in a single evening that I would typically see in an entire summer.

      If I were more hopeful, I’d like to think our agricultural pesticides are less lethal to charismatic insects like lightning bugs. But that would be expecting pesticides to have good chemical aim–and why should they? Many beetles are pests, and lightning bugs are genetically almost identical to the ones farmers are trying to eliminate.

      I at least achieve some reassurance by recognizing that lightning bugs are still abundant in rural areas, and–even better–they’re easy to find in tiny forested mini-habitats surrounded by urbanization. But they sure aren’t easy to find in the typical suburban back yard.

      Reply
    1. AmericanDirt Post author

      I bet you’re far enough away from the streetlights these days that you probably get bunches of ’em in your back yard!

      Reply
  4. Oran Sands

    Insecticides in the lawn treatments kill the larva. I stopped treatments for several years and saw them come back.

    Reply
    1. AmericanDirt Post author

      Glad to hear they came back. I’m sure a lot of suburban back yards use insecticides. But they did in the 80s and 90s as well, and it seemed like we still had a lot more lightning bugs back then.

      Reply

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