OBJECT OF THE MONTH - JULY 2004
Ode to a Firefly (Photuris sp.)
Dorsal view of Photuris sp. specimen. This particular specimen was found in Boulder, Colorado along the Boulder Creek on July 18, 1978. (UCMC0009175)
Twinkle, twinkle firefly,
Why do you light up the night sky?
Is it just to find a date?
Or do you flash to fill your plate?
Twinkle, twinkle firefly,
Why do you light up the night sky?
Fireflies, also known as lightning bugs, are soft-winged beetles, which belong to the Lampyridae family. They lay eggs in damp soil along ponds, rivers and in wetlands. The larvae live in these moist habitats where they feast on slugs, snails, and other invertebrates. After pupating, they emerge as adults.
Currently, fireflies are very prevalent in Colorado, but you might not notice Colorado's most common firefly species because they do not flash. In fact, some firefly species are not able to produce light at all. Alas, these small (ΒΌ inch) day-flying, black and red species have no "lanterns".
Ventral view of Photuris sp. specimen. The yellow-orange segments at the tip make up the firefly's "lantern."
Colorado's most famous fireflies do produce light, however. Usually, the flash is used to attract mates. The light produced is a cold light - almost all the energy goes into producing it - unlike the typical light bulb, which produces light as well as heat. The firefly produces light when a compound named luciferin and an enzyme named lucierase combine in the presence of oxygen. The flash patterns for different species are unique and some species identifications, such as species in the genus Photuris, are based on these flash patterns because the morphology between species is indistinguishable.
Some females of the genus Photuris use their ability to flash to attract dinner as well as potential dates. These females flash in a way that mimics the flash patterns of different species of firefly. When the unsuspecting male of the other species comes to find his mate, he is instead greeted by the hungry Photuris female, who proceeds to devour him on the spot.
Colorado is home to several species of fireflies that flash, but you have to hunt for them. In the Front Range area, you can find flashing fireflies at St. Vrain (Barbour Ponds) State Park, Roxborough State Park, and other moist habitats in early July at dusk. Just look for the twinkling lights.
