This female Photinus pyralis has brought in several males. In contrast to the large light-producing organ of the male, that of the female is smaller and confined to a single segment. Urbana, Illinois, USA
A small male Photinus pyralis firefly mates with a female. Small males aren't as luminous or easy to see as large males, but they are more agile. Field studies have shown that small males are more successful at mating than large males when many males are present. Urbana, Illinois, USA
Their luminous courtship succesful, a pair of big dipper fireflies Photinus pyralis mate in the grass. The female (at top) has much smaller light organ than the male. Urbana, Illinois, USA
