Fireflies Light Up My Life
Last night I was so excited to see tons of fireflies at our new home. Firefly populations are dwindling and since the bugs pretty much live, mate and lay eggs where ever they are born, I am always anxious to see what our yard will yield every time we move. Sturbridge, MA – lots of fireflies; Alabama – no fireflies; Oregon – no fireflies; Wisconsin – lots of fireflies; First home in Wilbraham – no fireflies; Second home in Wilbraham – lots of fireflies!
I have always been fascinated by light-producing animals. In addition to giving my children and I a fun display to watch at night, fireflies are also important scientifically. Today I thought I would enlighten your life with a few firefly facts!
The light of love. One of the main functions of the nightly fireworks display is to attract a mate. In most species, both males and females glow. The male will fly around flashing waiting for a signal from a waiting female.
Fireflies are cannibals. Fireflies are carnivorous and the larvae will eat snails and worms. Some species will eat other fireflies. In fact, in one species, the female will imitate the flash of another species to attract its males for a tasty meal!
Fireflies are extremely efficient at producing light. Unlike us energy-wasting humans, fireflies turn 100% of energy into light – therefore they do not give off heat when flashing. In comparison, an incandescent bulb only emits 10% of energy as light, with the rest being heat energy.
Fireflies use two chemicals to emit light. Luciferase and luciferin are the two chemicals found in firefly tails. Luciferase is an enzyme that acts on luciferin to switch on the familiar flash.
Luciferase in the lab. Luciferase and luciferin have been cloned and are commonly used in experiments. Luciferase is used as a “reporter protein”. Let’s say you want to find out how much of a particular protein a cell makes. You hook luciferase up to the protein, mix it with some luciferin and every time one of the proteins is present, it can make a bit of light. By measuring how much light is made, you can tell how much protein is in the cell. This assay was used every week in my lab.
Luciferin and luciferase are also being used to build electronic sensors that can detect food spoilage or bacterial contamination.
Why are firefly populations dwindling? Like many creatures on this earth, fireflies seem to be disappearing. Although we do not know exactly why, several factors are probably contributing to the loss of fireflies; most notably development of their natural habitats by humans (forests, fields and marshes, which explains the abundance of fireflies at our new home) and light pollution. Scientists speculate that man-made night lights disrupt firefly flash patterns which are used for finding mates, defending territories and warning off predators.
It makes me sad to think that future generations of children might not get to enjoy chasing fireflies. Although luciferase is fun to work with in the lab, it is much more fun when naturally produced!