Lights over Brown Mountain & Catawba Valley Light Pollution---June 26, 2013

Photography from Wiseman's View June 26, 2013

City lights of Lenoir east of Brown Mountain

55 minutes after sunset

Table Rock on the east rim of Linville Gorge can be seen on the right edge of the image

Tripod-mounted Canon EOS REBEL T3i DSLR camera w/ 18 mm lens,

f/4.5, 45 second exposure, ISO-400

 Light Pollution from Catawba Valley east of Table Rock

1 hour & 36 minutes after sunset

Collective Glow of City lights from Hickory & nearby towns reflecting off high thin clouds

Individual lights near Lenoir are visible over Brown Mountain on left side of image

Several short star trails are visible in the sky over Table Rock

Tripod-mounted Canon EOS REBEL T3i DSLR camera w/ 25 mm lens,

f/4.5, 122 second exposure, ISO-400

 

Comparing Blue Ghost Fireflies with common yellow-blinking fireflies

This image shows a direct size comparison between adult male specimens of the smaller Blue Ghost Firefly (Phausis reticulata) and the larger more common yellow-blinking firefly (Photinus pyralis).  Both fireflies are lying on their backs, exposing their undersides.  Although not lighted in the image, the two bioluminescent tail segments on each specimen are obvious, with the pale bluish white color of the smaller Phausis reticulata and the pale yellowish color of the larger Photinus pyralis.  This image clearly shows that the BGF is less than half the size of the more common yellow-blinking firefly, while it's bioluminescent segments are only about 1/20th as large!  However, when seen in the total darkness of a moonless night deep in the forest, the continuous burn of the BGF can seem very bright and eerie indeed.

Photo by Ed Speer
Canon REBEL EOS DSLR T3i camera (f/2.8, 1/60 sec, ISO-800, 50 mm lens)

& AmScope binocular microscope SM-1T (7X magnification)

The smaller firefly (Phausis reticulata) has a broken antenna. 

The length measurements were taken from the far end of the antennas to the tail end of each firefly.

Fireflies from Brue Ridge Parkway

Fireflies Monday, June 17, 2013 near mile 342.1 on Blue Ridge Parkway, McDowell Co, NC.

These 3 images show two types of fireflies at the same time.  The common yellow-blinking firefly Photinus pyralis, and the rare long-burning Blue Ghost Firefly (BGF), Phausis reticulata.  These time exposures show the greenish-yellow dashed flight paths of the common firefly and the long continuous greenish flight paths of the BGF.  Click on the individual photos to see larger images.  The common firefly (Photinus pyralis) began flying first as darkness fell, followed a few minutes later by Phausis reticulata.  The brighter light of the the common firefly greatly overshadowed the dim BGF for the first hour or so until the common firefly diseminated upward leaving the BGFs more readily visible near the ground. This population of BGFs is at 3,800' elevatin and is about 25 mi SE of Brown Mountain. 

Specifically it is situations where only 1 or 2 BGFs are present at any given time in a totally dark forest that could be mistaken for mysterious Brown Mountain Lights by an uninformed or unsuspecting individual.

 

These time exposure photos were taken with a tripod-mounted Canon EOS REBEL T3i DSLR camera with a 50 mm lens set near infinity focus, f/2.5 and ISO-6400

More Blue Ghost Firefly Images from DuPont State Forest

Several members of our BMLs Research Team viewed the BGFs again last night at DuPont State Forest in Transylvania Co., NC.  These time-exposure images were taken with a tripod-mounted Canon EOS REBEL T3i DSLR camera with a 50 mm lens set at near-infinity focus.

Blue Ghost Fireflies (Phausis reticulata)

DuPont Forest State Park, NC

 

43 second time exposure

60 second time exposure

70 second time exposure

60 second time exposure

 

Clicking on an individual image brings up a larger and more readily visible version of that image.  The male BGFs fly near the ground with their bioluminescent light continuously burning for several seconds to several minutes while searching for the females that live in the leaf litters on the forest floor.  The long flight paths seen in the images show that individual flight distances can be 100 feet or more.  To the human eye, the faint light appers white or bluish white, while the camera detects it as greenish white lights.

 

Sightings of Blue Ghost Fireflies by uninformed and unsuspecting individuals may explain a few reported mystery light close encounters with suspected Brown Mountain Lights.  While the existence of BGFs haven't yet been confirmed on Brown Mountain itself, they have been seen on North Harper Creek (Ed Speer, 2006, personal communication), only 5.5 miles north of the mountain.

Can Fireflies explain the Brown Mountain Lights?

Can fireflies explain the BMLs?

Of course not, at least not the majority of the reported light sightings.  But now that I have your attention, I'd like to introduce you to the Blue Ghost Firefly (BGF)----Phausis reticulata, which I suspect has fooled some people in the past. 

 

Blue Ghost Fireflies (Phausis reticulata)

DuPont State Forest, Transylvania Co., NC

This 62-second time exposure of the rare and little-known BGF shows a hatch of males flying between trees and brush in search of females which don't fly, but instead live on the forest floor.  Unlike the quick blinking of the common yellow firefly, the male BGF stays lighted for several seconds to several minutes while flying about 2 feet off the ground for horizontal distances up to 100 feet or more.  To the human eye, the BGFs burn with a pale bluish white light---however, the camera records a pale lime green color which appears to be the true color.

 Canon EOS REBEL T3i DSLR camera, f/2.5, 62 second exposure, ISO 6400, 50 mm lens

 

When seen for the first time by an uninformed or unsespecting person, the BGFs certainly can be mysterious and eerie.  Especially when encountered on a dark night in unfamiliar woods, the BGFs can be misintrepreted as sightings of distant bright lights rather than close encounters with a pale-light bioluminescent flying beetle. 

 

 

Phausis reticulata (Blue Ghost Firefly)

male on left, female on right

 

The most definitive research on the BGF is presented by Jennifer Frick-Ruppert & Joshua Rosen (2008) and can be found online at: http://www2.brevard.edu/jefrick/Blue%20Ghost%20pub.pdfhttp://www2.brevard.edu/jefrick/Blue%20Ghost%20pub.pdf

 

In the published literature of the Brown Mountain Lights, several light encounters may be consistant with the BGF.  Specifically, the 1916 account of H.C. Martin and Dr. L.H. Coffey (Pearson, 1916), the 1962 account of P. Rose (Charlotte Observer & Winston-Salem Journal, August 3, 1962), and the 1962 alien-abduction account of R. Lael (Lael, 1965).

 

While the BGFs don't explain the vast majority of BML distant light sightings (afterall, the BGFs can't be seen more than about 100 feet away), they may explain a small portion of some close-encounters with mystery lights.