Identification: The Pennsylvania Firefly, our largest, is the only Photuris in Ontario, extending north to Thunder Bay.
Head: Dull yellow with huge eyes. Area at back of head reddish-brown.
Antenna: Long, black, striped. Base of each segment white. 11 segments on both male and female.
Thorax (Pronotum): Triangular, front tip (base) rounded. Center has a round red spot with a black stripe (wider at each end) through the middle of red spot. Black stripe extends the length of the thorax. Rest of thorax yellow. Slightly covered with yellowish pile or very short hair.
Wings (Elytra): Dark brown with wide gold border on outside edge, narrowing at tip and continuing up inside edge of wings (suture). Each wing has a golden stripe from base to about mid wing, often very faint. Center of base of wings (scutellum) has a golden triangle.
Legs: Long and thick. Thighs (femora) yellow with a wide brown ring nearer tip. Shins (tibiae) have yellow base, rest brown. Feet dark, base of each segment yellow.
Abdomen: Black. Male underside has two yellow segments (light organs) before golden tip. Flashes green.
Size: 15 to 20 mm long – our largest firefly.
Habitat: Wet forests, marshes; resting on leaves of Tuliptree, Sycamore and Sumac.
Food: Predators of other fireflies.
Flight Time: Mid-June to end of July
Life Cycle: Little is known of mating habits, but assumed they mate high up in trees. Gravid females can mimic the flash patterns of Photinus females, luring the Photinus males to them. The males are then killed and eaten. They also prey on Pyractomena species. Eggs are laid in loose, well-drained, loamy soil. Larvae stay underground during the day, and use tunnels to the surface only at night to hunt, preferring slugs and snails and other small insects; also grapes. Both larvae and adults flash green.
Comments: Essex County – Point Pelee National Park and Ojibway Prairies. Kent County – Rondeau Provincial Park. A common species extending up to Thunder Bay on Lake Superior.
For information on synonyms, references and type specimens see next page