Species Photinus pyralis

Big Dipper Firefly

Photinus pyralis (Linnaeus 1767)

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.

Adults are frequently claimed to be incapable of feeding(3) but are capable of doing so (Case, 2004). Larvae predaceous on insect larvae, slugs, snails(3).

Eggs are laid on moist soil. Larvae take two summers to complete growth, overwintering twice, pupate in (spring?) in chambers in moist soil (3).

Case, J.F. 2004. Flight Studies on Photic Communication by the Firefly Photinus pyralis. Integrative and Comparative Biology 44(3): 250–258.