Twinkle, twinkle, little star…uh, er, or should I say, little bug… or really, little beetle? Summer is when we get to enjoy these delightful little creatures that flash and twinkle. The mere sight of which reminds us of blissful youth when the main occupation on many summer nights was running through the grass catching as many lightning bugs, or fireflies to some of you, as possible and casting them into the mayonnaise jar. The whole jar would be blinking secret Morse code, as we would gaze with wonder. Then run and catch more, trying carefully to slip one in without squishing another in the lid!
Lightning bugs don’t bite, they have no pincers, they don’t attack, they don’t carry disease, they are not poisonous, they don’t even fly very fast, and they’ll keep kids entertained for hours on end. Making them perfect in just about every way!
How do they do it? These amazing insects are one of the Midwest’s most unusual wildlife with their bioluminescence capabilities. The age-old question is how do they do it? You know, the lightning part. Biologists have studied this for years and have figured it out. The taillight contains two rare chemicals, a heat resistant substrate called luciferin, is the source of light, and an enzyme luciferase is the trigger. Oxygen is the fuel. A body chemical, ATP, converts to energy, mixes with the oxygen and causes the luciferin-luciferacse to light up, producing our favorite light of the summer! Firefly light!
This unique light is 100 percent efficient! Nearly 100 percent of lightning bug light is given off as light; in our incandescent electric lights, only 10 percent is light, 90 percent is wasted as heat. Talk about GREEN energy!
When a firefly is under stress (like being caught in spider web) its taillight glows brightly. Even the shock of a firecracker, or thunder may cause a field of fireflies to flash in unison. Warmer weather will cause faster blinks between potential mates, whereas cool weather calms things down a bit and they may wait even up to 5 seconds between short flashes.
If you grew up in the Midwest, you know that the best time to catch lightning bugs is at dusk when they become active. The males leave their resting spots and fly through the air blinking the code of their species, the females rest in the grass blinking their flirtatious corresponding code. When the codes match, the males come in for mating. There is one predator species, where the female fakes her code that attracts males of other species. When they come in for the landing, she eats them. Male lightning bugs outnumber females, 50 to one!
The Biology: Females deposit the eggs into damp soil, and in about three weeks larvae will appear from the eggs. The eggs themselves may even show a touch of luminescence. Although the adults are harmless, the larvae are voracious predators that eat snails, slugs, cutworms, mites, and pollen.
The one thing I know that is best to do with lightning bugs is to clean out the mayonnaise jar, turn off the lights, sit outside and …twinkle, twinkle, little bug…
-- Lynn Youngblood is the Executive Director of the Blue River Watershed Association in Kansas City, Missouri. Reach her at TheGreenSpace@sbcglobal.net