n Creature Feature

summer evenings are male. Fe- Fireflies (Lampyridae spp.) males rest on grasses and shrubs, watching and flashing back. At- tracted males approach and mate. The female of the genus Photuris, known as a tiger firefly, uses the same method but adds a twist. After it mates, it imitates flash pat- terns of other firefly species to set a trap. Then it eats the eager male. A few days after mating, females move to damp areas in meadows, forest edges, along streams, or near wetlands, de- pending upon species. They lay up to 200 glowing eggs in moist soil. The eggs hatch three to four weeks later when a small brown segmented larva emerges. The larva’s eighth segment produces green light, earning the common

John Maxwell photo name glowworm. Some scientists say the glowing eggs and larva an- One of our most beloved insects, fireflies do more than make summer nights sparkle. The bugs also can inspire medical research and exercise. nounce to predators that they are toxic or distasteful. Firefly larvae spend much of By Barbara Tibbets their time eating and growing. Like spiders, the larvae inject ireflies play an important role to propel the firefly through the air. prey (other insect larvae, slugs Fin nature beyond providing In spite of the name, some adults and snails) with digestive en- pyrotechnics. don’t produce light. In Indiana, 13 zymes, then feed on the resulting They loosen soil, allowing varieties fly only during the day— slurry. They can even kill earth- oxygen, sunlight and water to we call them lightning bug fireflies, worms, after which several glow- penetrate. They maintain balance and they attract mates by scent. worms might share the spoils. by eating impressive quantities At least 30 other types of “dark” In autumn they burrow under- of food while in the larval form. fireflies emerge when the sum- ground to hibernate through Although toxic to many potential mer sun sets in Indiana, flashing winter, coming out in spring to diners, they are eaten by spiders, patterns and colors to find mates. feed for a few more weeks. They frogs and other insects. Many also flash rapidly when burrow again to pupate, emerging Their light-producing chemi- caught in a spider web or placed in June or July as adults. Mature cals (luciferin and luciferase) in a jar, a stress reaction that oth- fireflies live a few weeks, long have been used in research on ers recognize as a danger signal. enough to restart the cycle. multiple sclerosis and cancer. The light is produced by Fireflies make good ambas- And they have been synthesized chemicals mixing with oxygen in sadors to the insect world for to make glow-sticks. the insect’s abdomen. The color, children. Use summer evenings They also provide beauty and intensity and duration of the to share your firefly knowledge entertainment, even serving as a flashes, along with movement, with them. Make humid, firefly- source for exercise while being allow fireflies to find each other. friendly catch jars by inserting a pursued by children on summer Although most of Indiana’s fireflies slice of apple and not punching evenings. don’t have common names, the holes in the lid. Fireflies, or lightning bugs, be- one known as the Big Dipper, Pho- After kids enjoy this natu- long to the beetle family Lampyri- tinus pyralis, is our most readily ral lantern, encourage them to dae. Like all beetles, they have two seen variety. It regularly graces release their catch, so the insects sets of wings. The top wings are lawns and roadsides as summer can heed the mating lightning. n tougher and shorter, covering the darkness falls. Its yellow flash lasts insect while at rest and providing up to three quarters of a second, Barbara Tibbets is the long-time inter- balance during flight. If lifted, the and it flies upward as it glows. pretive naturalist for Turkey Run and second set of longer wings unfolds The fireflies darting through our Shades state parks.

10 May/June 2013 n OutdoorIndiana.org