Montshire Minute: Fireflies

Originally aired during the week of May 27, 2002

Monday

Have you ever caught lightning in a bottle? I'll bet you have! I remember catching fireflies with a net, putting them in a mayonnaise jar, and watching them flash and glow brightly enough to read a book by. Here's a few other illuminating things about these creatures. For one thing, a firefly is not a fly at all. It is a beetle! Like other beetles, the firefly has a pair of mandibles and hard, shell-like outer wings, which protect the lightweight flying wings underneath. Worldwide there are about 2,000 different species of fireflies, with about 170 of them living in the U.S. When Montshire's new Leonard M. Rieser Learning Center opens on Saturday, June 8, there will be exhibits on local species of fireflies in which we attempt to decode the complex flash patterns made by these flies. I mean beetles.

Tuesday

Fireflies really know how to glow - it's a natural gift. They even glow in the larval stage! After hatching, firefly larvae (sometimes they are called glow worms) set about preying on earthworms, snails or slugs. It's not known what advantage glowing gives to the larvae. It may be a signal for other larvae to gang up on larger prey - several larvae are often observed sharing the same kill. Perhaps the glow is a warning sign to predators that it's not good to eat. On the other hand, frogs have been known to gorge themselves on firefly larvae to the extent that they glow themselves! It's been suggested that glowing is one way to attract prey. One scientist noted that a certain species of firefly tended to glow more brightly when it was ready to enter the pupal stage. As you can see, there is a lot more light future scientists can shed on the firefly larvae's gift of glowing!

Wednesday

Fireflies are all light and no heat. They have light-producing chemicals in special organs inside their abdomens. The light they produce has been called perfect light because very little heat is given off as wasted energy. Unlike a standard light bulb, for instance, which generates more heat energy than light. Some researchers think the firefly can turn itself on and off by controlling the oxygen supply to the photic organ. Others believe the insect has neural control over the process. In any event, the flash patterns made by the insects seem to be an important part of introducing the ladies to the gents. In most cases, it's the males that cruise above the ground, flashing their taillights, looking for action. The females wait demurely on the ground, sending signals back up to their future mates.

Thursday

OK, that's dot-dash-dot . . . dot-dot-dash . . . dash-dot-dash . . . oh, hello there! Just trying to decipher this semaphore that's happening right in my backyard. See, the patterns of these firefly flashes really mean something. I don't know what they are saying exactly, but I can tell you this: it all boils down to sex. You see, flashing is the way male and female fireflies talk to each other. Each species of firefly has a distinctive flash pattern. If you're a real expert, you can decode the signals based on the number of flashes, the duration of the flashes, and the intervals between them. A short flash dialogue may take place as the flying male locates the female's position on the ground. But the male firefly has to be careful. He could fall prey to an "aggressive mimic." You know the type - they promise you the world, then they attack and eat you!

Friday

With all this talk about fireflies on the program this week, you're probably wondering: Neal, how can I attract more fireflies to my backyard? Well here are a few things to keep in mind: some firefly species aren't active when here is a lot of ambient light. So try cutting down on the amount of outdoor lighting on your property. Also, low overhanging trees, tall grass, or similar vegetation will provide good habitat for adult fireflies during the day. It's a good excuse for not mowing the lawn. While we're on the topic, stop by Montshire to see our new Firefly House - it's one of many new exhibits on the natural history of the Connecticut River watershed opening Saturday, June 8. The Firefly House shows how each species of firefly has a distinctive flash pattern. Help us decode firefly signals based on the number of flashes, the duration of the flashes, and the intervals between them.