Big Dipper Firefly: Yellow Green Twilight Flashes of Photinus pyralis

Summary: Big Dipper Firefly (Photinus pyralis), also known as Common Eastern Firefly, is North America's commonest firefly, flashing yellow green light at twilight.

Photinus pyralis and Felis domesticus: Terry Priest (art farmer), CC BY SA 2.0, via Flickr

New World native insect Photinus pyralis is the most common firefly in North America. The light-producing beetle claims homelands throughout the central and eastern United States east of the Rocky Mountains.

Photinus pyralis (Ancient Greek: φῶς, phôs, "light” + Ancient Greek: πῦρ, pûr, “fire”) is known commonly in English as Big Dipper Firefly or as Common Eastern Firefly.

The common name of Big Dipper reflects the J-shaped pattern flashed on the upswing by roving Photinus pyralis males.

The common name of Common Eastern Firefly acknowledges the flighty, light-producing beetle's status as the most common firefly east of the Rocky Mountains.

The firefly, or lightning bug beetle, joins two other insects -- ladybug and honeybee – in Tennessee’s official state insect trio.

In 1975, Tennessee designated fireflies, of which Photinus pyralis is the most familiar, and the seven-spotted ladybug (Coccinella septempunctata), also known as C-7, as state insects (Tennessee Code Annotates, Title 4, Chapter 1, Part 3, Section 4-1-308).

In 1990, the honeybee (Apis mellifera) was designated as official state agricultural insect.

The Common Eastern Firefly flits happily across agricultural, riparian (Latin: riparius, “of a river bank”), and suburban environments. Preferred landscapes emphasize meadows, streams, and woodland edges.

With a maximum adult length of around 0.5 inches (14 millimeters), Big Dipper Fireflies have six jointed legs and a three-part dark brown body.

The rounded head is outlined in yellow with two orange accent spots, two antennae and compound eyes.

The second segment, the thorax (Latin: thorax, "breastplate, chest"; from Ancient Greek: θώραξ, thṓraks, “breastplate, chest”), features two pairs of wings. Males use the second pair for flying while short-winged females seldom fly.

The last section is a flattened abdomen with light emission capability.

As a member of the winged beetle order of Coleoptera (Ancient Greek: κολεός, koleós, "sheath” + πτερόν, pterón, "wing”), the attractive insect in the firefly family of Lampyridae (Ancient Greek: λαμπάς, lampás, "lamp, light”) has elytra (Ancient Greek: ἔλυτρον, élutron, "sheath”). The pair of front wings functions as protective cover for underwings. Big Dipper Firefly elytra are dark brown accented with narrow yellow margins.

Firefly illumination derives from bioluminescence, a form of chemoluminescence in which a chemical reaction in a living organism produces and emits light. Fireflies flash light at twilight to attract mates. As a member of Photinus, the lightning bug genus known as rover fireflies, Photinus pyralis features solitary roving rather than group flying by males flashing for females.

Big Dipper Fireflies light up their world in a palette that includes greenish blue, yellow green, reddish white and white orange.

At twilight, from late spring through autumn, my black-and-white Maine coon kittycat, Augusta "Gusty" Sunshine, likes to position herself on the soft needles carpeting the ground around the more westerly of the two Eastern White Pines (Pinus strobus) demarcating the northern borders of the upper north terrace's shade garden.

As she sits elegantly and reflectively, on her haunches or in sphinx pose, Big Dipper Fireflies spiral around her, illuminating "Gusty Gus" and the Eastern White pines with their rhythmic yellow green flashes.

Photinus pyralis: art farmer from evansville indiana, usa, CC BY SA 2.0, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Photinus pyralis and Felis domesticus: Terry Priest (art farmer), CC BY SA 2.0, via Flickr @ https://www.flickr.com/photos/artfarmer/643081671/

Photinus pyralis: art farmer from evansville indiana, usa, CC BY SA 2.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Photinus_pyralis_Firefly_4.jpg

For further information:

“How These Beetles Create Light.” The Washington Post > Metro. July 10, 2009.
Available @ http://www.washingtonpost.com/wp-dyn/content/graphic/2009/07/11/GR2009071103099.html

Marriner, Derdriu. "Book Review: The Fireflies Book by Brett Ortler." Wizzley > Pets & Animals > Insects > Other Insects.
Available @ https://wizzley.com/book-review-the-fireflies-book-by-brett-ortler/

"Photinus pyralis Common Eastern Firefly." Encyclopedia of Life.
Available @ http://eol.org/pages/1173778/details

"Photinus pyralis Firefly." BioWeb UW LaCrosse > Biology 210 > Matousek Hann.
Available @ http://bioweb.uwlax.edu/bio210/s2013/matousek_hann/classification.htm

"Tennessee State Insects." Netstate > States > Symbols > Insects.
Available @ http://www.netstate.com/states/symb/insects/tn_insects.htm

"Types of Fireflies." Firefly.
Available @ http://www.firefly.org/types-of-fireflies.html