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Pennsylvania Firefly Photuris pennsylvanicus


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Pennsylvania Firefly
credit: USFWS

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Alternate name: Lightning Bug

Family: Lampyridae, Fireflies view all from this family

Description Somewhat flattened beetle with threadlike antennae; large, widely separated eyes; and head clearly visible from above. Primarily black, with two bright-red eyespots on its thorax and yellow edging on thorax and wing case. The terminal segments of its abdomen are white-yellow and glow every 2-3 seconds while flying. Both sexes with flashing green light. Larva spindle-shaped with light organ below abdomen at rear.

Dimensions 3/8-5/8" (9-15 mm)

Food Carnivorous, feeding mostly on insects, but also on invertebrates such as land snails on occasion.

Life Cycle Eggs laid singly among rotting wood or humid debris on ground. Larvae (also known as glowworms) hatch in spring. grow throuth summer and then overwinter in pupal chambers just below soil surface. Pupate the following spring with adults emerging early summer to late August.

Habitat Open woods and meadows.

Range East Coast to Texas, north to Manitoba.

Discussion Also known as Pennsylvania firefly, lightning bug, Pennsylvania lightning bug, and (in its larval state) glowworm. Eggs, larvae, and pupae luminous as well as adults