Delta Journal
by Bob Thomas

Most of us cherish the memories of summer nights during our childhood when we played hide-n-seek and caught fireflies, or lightning bugs. The bugs (actually beetles) were a curiosity and just plain fun, but their story is fascinating indeed.

The special light they produce, termed bioluminescence, is exactly like that produced by comb jellies, glow worms, and all other light-producing life forms. A special substance called luciferin mixes with oxygen and produces oxy-luciferin, water, and light. All of the energy output is light - there is no waste in the form of heat as in all human-produced light. This alone is truly remarkable.

The biological purpose for the light is to attract a mate to produce many more lightning bugs. The males fly about blinking while the receptive females sit on vegetation and return the signal. Since the blinking of the light is a signal for mating, one might guess that each species has its own technique. In fact, its fun to watch fireflies closely to see if you can detect differences among those flying about. Do they all blink the same number of times before remaining unlighted? Do they use the same sequence of short and/or long blinks? Do you see different blinking combinations flying at different heights? Different times of the night? What other differences do you detect?

Fireflies are carnivorous as adults and larvae. Since they eat other insects, it is not surprising to learn that some of them will mimic the reproductive blinks of other species. When they attract the other insect, they grab and devour it quickly! What a turn of events for the unsuspecting prey! Thinking of love and becoming lunch!

Our world is full of trade offs. Since we have controlled mosquito populations and developed more land, we seem to have fewer fireflies. Two places in and near New Orleans where they can still be easily found is the Nature Center in Joe Brown Park and the Barataria Unit of Jean Lafitte National Historical Park and Preserve.