Big Dipper Firefly

• comportamientoIn some populations it synchronises its flashes with nearby males, producing coordinated collective displays whose exact purpose is still under study.
• As it flies, the male traces a luminous J every five to seven seconds: hence its name, the big dipper firefly, after the constellation.
• It gives off light at all four stages of its life, the egg included, and not only for mating: it advertises that it carries lucibufagins, steroids that make it inedible.
• Females of the genus Photuris mimic this species' flash to lure the males in and eat them, thereby stealing the lucibufagins they cannot make themselves.
• The larva is a predator: it hunts snails, slugs and earthworms, injecting digestive enzymes through hollow jaws, and takes one or two years to develop.
• The adult barely feeds, and lives from a few days to two months. Light pollution interferes directly with its courtship signals.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Damp meadows, woodland edges, gardens and the margins of lakes and streams in the eastern and central United States; the larvae live buried in moist soil and leaf litter

Size at birth

Round egg about 0.8 mm across, laid in damp crevices

Sexual maturity

The adult emerges from the pupa with vestigial mouthparts and does not feed: it lives on the reserves built up during the larval stage and devotes itself solely to breeding

Gestation / incubation

The eggs hatch between 18 and 25 days after laying; the larval stage lasts one to two years and the pupa 9 to 15 days

Litter / clutch size

About 500 eggs per female

Sources consulted: Wikipedia (en): Photinus pyralis · LSU AgCenter, ficha Big Dipper firefly · Animal Diversity Web · Animal Diversity Web, Photinus pyralis

Best time: Summer, at nightfall: the males begin to flash between 20 minutes before sunset in closed woodland and 11 minutes after in open country, and carry on for about 90 minutes

The pins mark the parks where its presence is documented.