Native Colorado Firefly (Coleoptera: Lampyridae: Pyropyga
sometimes called the lightning bug, is neither a fly nor a bug, and
there is no fire or lightning involved. It is actually a beetle
(Coleoptera). The firefly is a predator, with larval stages feeding
upon potential garden pests such as snails and caterpillars. Adults
tend to prey on aphids and scale insects.
They are more often found in areas with higher humidity and
moisture, like lakes, ponds and golf courses.
Fireflies produce their light in an organ at the end of their
abdomen. This organ is full of a chemical called luciferin. When
the enzyme luciferase is released into the chamber, light is
generated. It's slightly more complicated than that, involving
oxygen and ATP but this isn't a biochem class. The beetle can
precisely control when it flashes and doesn't flash which is
important for mating.
One neat fact about this bioluminescence is that it produces no
heat. It's akin to those break and shake glow sticks; the chemical
reaction is based upon the firefly's luciferin/luciferase
During mating season, females will perch in foliage and flash a
species-specific pattern. The males flying around her will flash a
response back letting her known that they are ready to mate. Some
species harbor femme
fatales. After she mates, she changes her pattern to another
species, lures a male in, and eats him. Talk about false
The most common firefly species found in Colorado are not able
to produce light. Sad but true. Pictured is one such specimen of a
fireless firefly, caught in Denver City Park, 8 October, 2010.
There are curious occurrences of thousands of fireflies
synchronizing their flashing. It is unclear to entomologists as to
why they do this. One thought is they are trying to bring Disco back,
but that is only a guess and could be wrong. Here's an example of
Further reading, more pictures, and other species: