The Basics
Fukatsu T, Moriyama M, Oguchi K, Kajimura H and Gugliuzzo A (2026) “Editorial: Diversity of beetles and associated microorganisms, volume II.” Frontiers in Microbiology. 17:1805361. www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2026.1805361/full
Insects Are Everywhere
N.E. Stork, J. McBroom, C. Gely, & A.J. Hamilton, “New approaches narrow global species estimates for beetles, insects, and terrestrial arthropods.” Proc. Natl. Acad. Sci. U.S.A. 112 (24) 7519-7523, https://doi.org/10.1073/pnas.1502408112 (2015).
Xin Li, John J Wiens, “Estimating Global Biodiversity: The Role of Cryptic Insect Species.” Systematic Biology, Volume 72, Issue 2, March 2023, Pages 391–403, https://doi.org/10.1093/sysbio/syac069
University of Florida Thompson Earth Systems Institute. “The Insect Effect: Insect Decline and the Future of Our Planet.” 2026.
www.floridamuseum.ufl.edu/earth-systems/the-insect-effect/
Rice University, Jeff Falk. “Biologists discover new insect species at Rice University.” January, 23, 2022. Press Release. https://news.rice.edu/news/2022/biologists-discover-new-insect-species-rice-university
Fireflies Near You
Fallon, Candace. Firefly Atlas. “A field guide to California’s fireflies.”
www.fireflyatlas.org/a-field-guide-to-californias-fireflies
Fireflies Around the World
Midwest Region Office of Communications, U.S. Fish and Wildlife Service. “Save the Fireflies.” www.fws.gov/story/save-fireflies
A number of different estimates and ranges exist for the overall global firefly species total and the North American species count. This in part because a fair number of species have been described recently, but also because firefly populations are in jeopardy, with some species threatened or even endangered (or data deficient). For this reason, please consider these only rough estimates, given that things are in flux.
Fireflies That Don’t Glow
Rooney, Jennifer, and Sara Lewis. “Notes on the Life History and Mating Behavior of Ellychnia Corrusca (Coleoptera: Lampyridae).” Florida Entomologist. no. 3 (200): 324-334. https://journals.flvc.org/flaent/article/view/59556
Bush-Pirkle, Merrik. “Spanish Fly Beetles Use Sex and Subterfuge to Infiltrate Bee’s Nests” Published by the Public Affairs Office at San Francisco State University, Diag Center. www.sciencedaily.com/releases/2000/05/000503190508.htm
Eisner, Thomas. For Love of Insects. Boston: The Belknap Press of Harvard University Press. 2005.
What’s in a Name?
Brown, R.W. Composition of scientific words: A manual of methods and a lexicon of materials for the practice of logotechnics. Washington, DC: Smithsonian Institution Press, 1956. Quoted in BugGuide.net: http://bugguide.net/node/view/12418
Weller, Susan. “Minnesota Profile Fireflies (family Lampyridae).” Minnesota Conservation Volunteer, July 2002.
Firefly Evolution
Smithsonian. “Bioluminescence First Evolved in Animals at Least 540 Million Years Ago.” News Release. April 23, 2024. www.si.edu/newsdesk/releases/bioluminescence-first-evolved-animals-least-540-million-years-ago
Lau ES, Oakley TH. “Multi-level convergence of complex traits and the evolution of bioluminescence.” Biol Rev Camb Philos Soc. 2021 Apr;96(2):673-691. https://pubmed.ncbi.nlm.nih.gov/33306257/ Epub 2020 Dec 11. PMID: 33306257.
Powell GS et al. 2022. “Beetle bioluminescence outshines extant aerial
predators.” Proc. R. Soc. B 289: 20220821. https://doi.org/10.1098/rspb.2022.0821
Firefly Eggs and Larvae
McKenzie, J. 2001. “Photinus pyralis” (Online). Animal Diversity Web. http://animaldiversity.ummz.umich.edu/accounts/Photinus_pyralis/
Oba Y, Furuhashi M, Bessho M, Sagawa S, Ikeya H, Inouye S. “Bioluminescence of a firefly pupa: involvement of a luciferase isotype in the dim glow of pupae and eggs in the Japanese firefly, Luciola lateralis.” Photochem Photobiol Sci. 2013 May;12(5):854-63. https://pubmed.ncbi.nlm.nih.gov/23407656/
Riley WB, Rosa SP, Lima da Silveira LF. “A comprehensive review and call for studies on firefly larvae.” PeerJ. 2021 Sep 20;9:e12121. https://pmc.ncbi.nlm.nih.gov/articles/PMC8459732/
Larvae Lunch
Riley WB, Rosa SP, Lima da Silveira LF. “A comprehensive review and call for studies on firefly larvae.” PeerJ. 2021 Sep 20;9:e12121. https://pmc.ncbi.nlm.nih.gov/articles/PMC8459732/
Why Larvae Glow
Riley WB, Rosa SP, Lima da Silveira LF. “A comprehensive review and call for studies on firefly larvae.” PeerJ. 2021 Sep 20;9:e12121. https://pmc.ncbi.nlm.nih.gov/articles/PMC8459732/
Sivinski, John. “The Nature and Possible Functions of Luminescence in Coleoptera Larvae.” The Coleopterists Bulletin 35, no. 2 (1981): 167–79. http://www.jstor.org/stable/4007935. Note: Sivinksi was quoting an earlier paper by Frank A. McDermott.
The Pupal Stage
Riley WB, Rosa SP, Lima da Silveira LF. “A comprehensive review and call for studies on firefly larvae.” PeerJ. 2021 Sep 20;9:e12121. https://pmc.ncbi.nlm.nih.gov/articles/PMC8459732/
Lantern Organs
Ghiradella H, Schmidt JT. “Fireflies at one hundred plus: a new look at flash control.” Integr Comp Biol. 2004 Jun;44(3):203-12. https://pubmed.ncbi.nlm.nih.gov/21676697/
Greenfield, Michael. (2001). “Missing link in firefly bioluminescence revealed: NO regulation of photocyte respiration.” BioEssays. 23. 992-995. https://pubmed.ncbi.nlm.nih.gov/11746215/
The Reaction Behind Firefly Light
Pennisi, Elizabeth. “For Fireflies, It’s a Gas.” Science. June 28, 2001.
www.science.org/content/article/fireflies-its-gas
Barbara Bitler, W.D. McElroy. “The preparation and properties of crystalline firefly luciferin.” Archives of Biochemistry and Biophysics, Volume 72, Issue 2, 1957. https://pubmed.ncbi.nlm.nih.gov/13479120/
A Cold Light
Branham, Marc. “How and why do fireflies light up?” Scientific American, September 5, 2005. www.scientificamerican.com/article.cfm?id=how-and-why-do-fireflies
The Science of Fireflies
Pliny the Elder. Natural History, Book XI. Accessed via Loeb Classical Library: https://www.loebclassics.com/display/pliny_elder-natural_history/1938/pb_LCL353.493.xml?readMode=recto
Lee, John. (2008). “Bioluminescence: the First 3000 Years (Review).” Biology. https://www.researchgate.net/publication/229052741_Bioluminescence_the_First_3000_Years_Review
How Do Fireflies Control When They Light Up?
Aprille JR, Lagace CJ, Modica-Napolitano J, Trimmer BA. “Role of nitric oxide and mitochondria in control of firefly flash.” Integr Comp Biol. 2004 Jun;44(3):213-9. https://pubmed.ncbi.nlm.nih.gov/21676698/
Firefly Brightness
Coblentz, William. A Physical Study of the Firefly. Washington, DC: Carnegie Institution of Washington, 1912.
David H. Silver; “How bright is a firefly? Resolving a century of overestimation.” Am. J. Phys. 1 July 2026; 94 (7): 520–524. https://doi.org/10.1119/5.0325834
The Science Behind the Firefly Color Palette
Seliger, H.H., Buck, J.B., Fastie, W.G., McElroy, W.D. “The Spectral Distribution of Firefly Light.” Journal of General Physiology. 1964 Sep;48(1):95-104. https://pubmed.ncbi.nlm.nih.gov/14212153/
Other Creatures with Bioluminescence
Haddock, Steven, Mark Moline, and James Case. “Bioluminescence in the Sea.” Annual Review of Marine Science. (2009): 443-493. http://adsabs.harvard.edu/abs/2010ARMS….2..443H
Shimomura, Osamu. Bioluminescence: Chemical Principles and Methods. Singapore: World Scientific Publishing Company. 2012.
Daston, M.M., and J.B. Copeland. “The luminescent organ and sexual maturity in Dyakia striata.” Institute of Malacology. no. 1 (1999): 9-19.
Another Way to Glow: Biofluorescence
Jeng, Ming-Luen. (2019). “Biofluorescence in Terrestrial Animals, with Emphasis on Fireflies: A Review and Field Observation.” Chapter of Bioluminescence—Analytical Applications and Basic Biology. www.researchgate.net/publication/335672888_Biofluorescence_in_Terrestrial_Animals_with_Emphasis_on_Fireflies_A_Review_and_Field_Observation
A World of Variation
Branham, Marc. “How and why do fireflies light up?” Scientific American, September 5, 2005. www.scientificamerican.com/article.cfm?id=how-and-why-do-fireflies
Lloyd, J.E. “Studies on the flash communication system in Photinus fireflies.” University of Michigan Museum of Zoology, Miscellaneous Publications, 130. (1966): 1-93. https://deepblue.lib.umich.edu/handle/2027.42/56374
Predator and Prey
Lloyd, James E. “Firefly Parasites and Predators.” The Coleopterists Bulletin 27, no. 2 (1973): 91–106. www.jstor.org/stable/3999442.
Reflex Bleeding: A Strange Survival Strategy
Xinhua Fu, Ohba Nobuyoshi, V. B. Meyer-Rochow, Yuyong Wang, and Chaoliang Lei “Reflex-bleeding in the Firefly Pyrocoelia pectoralis (Coleoptera: Lampyridae): Morphological Basis and Possible Function.” The Coleopterists Bulletin 60(3), 207-215, (2 November 2006). https://doi.org/10.1649/892.1
Don’t Feed Fireflies to Your Pet . . . or Your Brother!
Eisner, Thomas, et al. “Two Cases of Firefly Toxicosis in Lizards” Journal of Chemical Ecology. no. 9 (1999): 1981-1986. https://link.springer.com/article/10.1023/A:1021072303515
The Photuris Fireflies: The Femme Fatales
- Eisner, M.A. Goetz, D.E. Hill, S.R. Smedley, & J. Meinwald, “Firefly “femmes fatales” acquire defensive steroids (lucibufagins) from their firefly prey.” Proc. Natl. Acad. Sci. U.S.A. 94 (18) 9723-9728, https://doi.org/10.1073/pnas.94.18.9723 (1997).
Freed LL, Easson C, Baker LJ, Fenolio D, Sutton TT, Khan Y, Blackwelder P, Hendry TA, Lopez JV. “Characterization of the microbiome and bioluminescent symbionts across life stages of Ceratioid Anglerfishes of the Gulf of Mexico.” FEMS Microbiol Ecol. 2019 Oct 1;95(10):fiz146. https://pmc.ncbi.nlm.nih.gov/articles/PMC6778416/
Lunch—and Something Extra
- Eisner, M.A. Goetz, D.E. Hill, S.R. Smedley, & J. Meinwald, “Firefly “femmes fatales” acquire defensive steroids (lucibufagins) from their firefly prey.” Proc. Natl. Acad. Sci. U.S.A. 94 (18) 9723-9728, https://www.pnas.org/doi/10.1073/pnas.94.18.9723
Eisner, Thomas. Google Scholar. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C24&q=thomas+eisner&btnG=
The Pyractomena Fireflies
Firefly Atlas. “Firefly Species Checklist, Pyractomena.” 2026.
www.fireflyatlas.org/firefly-species/firefly-species-checklist
A Synchronized Show in the Great Smokies
National Park Service. “Synchronous Fireflies.” 2026.
www.nps.gov/grsm/learn/nature/fireflies.htm
Why Synchronize?
National Park Service. “Synchronous Fireflies.” 2026.
www.nps.gov/grsm/learn/nature/fireflies.htm
Moiseff, Andrew, and Jonathan Copeland. “Firefly Synchrony: A Behavioral Strategy
to Minimize Visual Clutter.” Science. no. 5988 (2010): 181. www.sciencemag.org/content/
329/5988/181.abstract?sid=4e04cf76-b362-4195-b1f0-7219d84bcea8
The Blue Ghost Firefly: A Steady Light in the Dark
Frick-Ruppert, Jennifer, and Joshua J. Rosen. “Morphology and Behavior of Phausis
reticulate (Blue Ghost Firefly).” Journal of the NC Academy of Science. no. 4 (2008):
139-147. https://pubmed.ncbi.nlm.nih.gov/20616271/
Yamasaki, Alisa. “Firefly festivals in the summer capture spirit of growing up in old
Japan.” The Japan Times. June 14, 2013. www.japantimes.co.jp/culture/2013/06/14/
events/firefly-festivals-in-the-summer-capture-spirit-of-growing-up-in-old-japan
The Blue Ghost Firefly
Frick-Ruppert, Jennifer, and Joshua J. Rosen. “Morphology and Behavior of Phausis
reticulate (Blue Ghost Firefly).” Journal of the NC Academy of Science. no. 4 (2008):
139-147. https://pubmed.ncbi.nlm.nih.gov/20616271/
Concerns for the Present (and the Future)
Midwest Region Office of Communications, U.S. Fish and Wildlife Service. “Save the Fireflies.” www.fws.gov/story/save-fireflies
The Problem with Insecticides
Glaberman S, Spatz K, Colbourne JK. “The evolutionary dilemma of broad-spectrum insecticides.” Bioscience. 2025 Jun 16;75(10):799-802. https://pmc.ncbi.nlm.nih.gov/articles/PMC12539341/
Advances Thanks to Fireflies
Smale ST. “Luciferase assay.” Cold Spring Harb Protoc. 2010 May;2010(5):pdb.prot5421. https://pubmed.ncbi.nlm.nih.gov/20439408/
Yeasen Bio.
“Bioluminescence Imaging: A Powerful Tool for Real-Time, In Vivo Research.” Jul 15, 2025. www.yeasenbio.com/blogs/cell/bioluminescence-imaging-a-powerful-tool-for-real-time-in-vivo-research
Cockerell, Jess. “Ozempic Literally Came From a Monster – And It’s Not Alone.” Science Alert.
www.sciencealert.com/ozempic-literally-came-from-a-monster-and-its-not-alone
Mythology
Lopes. Luís. “Some Notes on Fireflies.” Mesoweb: An Exploration of Mesoamerican Cultures. 2004. www.mesoweb.com/features/lopes/Fireflies.pdf
Fireflies, Poets, and Playwrights
William Shakespeare. Pericles, Prince of Tyre. Barbara Mowat, Paul Werstine, Michael Poston, Rebecca Niles, eds (Washington, DC: Folger Shakespeare Library, n.d.). https://www.folger.edu/explore/shakespeares-works/pericles/read//
Firefly Distribution
Firefly distribution map based on my interpretation of iNaturalist observations (www.inaturalist.org/home), Firefly Atlas reports (https://www.fireflyatlas.org/map), and legacy Firefly Watch data (www.massaudubon.org/programs-events/community-science/firefly-watch). Please note: This map is only a very rough approximation.
Season Calendar
This chart was produced after referring to legacy data from the Firefly Watch Project, run first by the Museum of Science and then the Massachusetts Audubon, over multiple years. I reviewed and sorted the data for each state, and I then omitted outlier data to attempt to establish when the bulk of a state’s sightings were reported. It’s only intended as a rough guide, but it should get you started.
The original data is accessible here: www.massaudubon.org/programs-events/community-science/firefly-watch
Firefly Flashing Patterns
All three charts based on data from: Lloyd, J.E. “Studies on the flash communication system in Photinus fireflies.” University of Michigan Museum of Zoology, Miscellaneous Publications, 130. (1966): 1-93.
http://deepblue.lib.umich.edu/handle/2027.42/56374
Firefly Tourism
National Park Service. Great Smoky Mountains National Park. “Synchronous Fireflies.” 2026.
www.nps.gov/grsm/learn/nature/fireflies.htm
National Park Service. Congaree National Park. “Plan Your Visit.”’ www.nps.gov/cong/planyourvisit/basicinfo.htm
Pennsylvania Firefly Festival
www.pafireflyevents.org