Photinus pyralis is the most common firefly in eastern North America. Characteristically, the males fly at dusk with distinct upward swoops. Urbana, Illinois, USA
A firefly, Photinus pyralis, in flight. Urbana, Illinois, USA
Female Photinus pyralis do not fly during courtship. Instead, they perch in vegetation at dusk and signal in response to a suitable male flash. Here, a female aims her light organ to signal back at a male. Urbana, Illinois, USA
