Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Species Photinus pyralis

Photinus pyralis - male Photinus pyralis Photinus pyralis Lampyiridae - Photinus? - Photinus pyralis Firefly - Photinus pyralis Large Firefly - Photinus pyralis - male Firefly - Photinus pyralis Beetle larva - Photinus pyralis
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
No Taxon (Series Elateriformia)
Superfamily Elateroidea (Click, Firefly and Soldier Beetles)
Family Lampyridae (Fireflies)
Subfamily Lampyrinae
Tribe Lucidotini
Genus Photinus
No Taxon (pyralis Group)
Species pyralis (Photinus pyralis)
Other Common Names
Big Dipper Firefly
Explanation of Names
Photinus pyralis (Linnaeus 1767)
pyralis = 'of fire'
9-15 mm(1)
Large for a Photinus. Blackish-brown finely, densely rugose (wrinkled) elytra, side margins and suture of elytra yellow. Pronotal disk pinkish with a black spot. Pronotum convex. Underside: Ventral abdominal segments six and seven large and occupied by light organ in male. Abdominal sternites of male have distinct (2). Female flightless (3), or "seldom" flies, as it does have normal wings (4).
Flash is distinctive: male hovers about two feet (0.6 m) above ground, then drops vertically, gives single prolonged flash as is ascending, then flash diminishes (2). Flashing occurs at dusk, earlier in evening than most other fireflies.
e US (NY-FL to NE-TX) (5)
Meadows and edges of woodlands, including lawns, suburbs.
Adult does not feed, larvae predaceous on insect larvae, slugs, snails(3).
Life Cycle
Eggs are laid on moist soil. Larvae take two summers to complete growth, overwintering twice, pupate in (spring?) in chambers in moist soil (3).
Works Cited
1.Revision of the Nearctic species of Photinus (Lampyridae: Coleoptera).
Green, J.W. 1956. Proceedings of the California Academy of Sciences 28: 561–613.
2.A Manual of Common Beetles of Eastern North America
Dillon, Elizabeth S., and Dillon, Lawrence. 1961. Row, Peterson, and Company.
3.National Audubon Society Field Guide to Insects and Spiders
Lorus and Margery Milne. 1980. Knopf.
4.The Common Insects of North America
Lester A. Swan, Charles S. Papp. 1972. Harper & Row.
5.Studies on the flash communication system in Photinus fireflies.
Lloyd, J.E. 1966. Museum of Zoology, University of Michigan 130: 1-95.