In the spring of 2004, much of the US's eastern coast experienced something amazing. People went into their backyards at night and saw sights similar to that at the right. Thousands of six-legged, honey-colored critters were seen crawling up shrubs, trees, fences, and birdbaths! This picture was taken by J. A. Pyle in Beltsville, Maryland.
Most people already knew what was happening because local TV stations and newspapers had informed them that the honey-colored things were the immature stages, or nymphs, of Periodical Cicadas. Cicadas are members of the Homoptera, family Cicadidae, genus Magicicada.
The deal is that seventeen years earlier adult cicadas had laid eggs in neighborhood trees. Later most of the twigs probably died or weakened, then snapped on a breezy day, broke off, and fell to the ground. What hatched from the egg inside the twig was not a small version of the adult cicada shown at the left with red eyes, but rather a small, wingless version of the brown thing at the bottom of the picture.
The brown thing then for 17 years burrowed underground feeding on roots. Then a couple of days before I made the picture at the left, the brown thing climbed up the trunk of a tree, dug its claws into the underside of a leaf, and then the brittle shell split open along its back. The picture at the left shows only one insect. The brownish item on the leaf below is nothing but the discarded external skeleton, or exoskeleton of the above cicada's former form. Insects don't have bones. They are encased in their skeletons.
The picture at the right, taken by J. A. Pyle in Beltsville, shows how it happened. Here the future adult is emerging from its exoskeleton. Once the pale adult is completely emerged, it will find someplace where it can remain quiet for a few hours as its new and larger exoskeleton hardens, darkens, and its wings expand tremendously, and stiffen. During this pale "softshell" stage, by the way, many people with oriental food-tastes like to gather the newly emerged adults, deep-fry them, and eat them like crunchy, high-protein popcorn!
Once the exoskeletons of the adults are hard and the wings are stiff, more amazing events unfold. For days now the landscape buzzes as millions and millions of cicadas call. These are males calling for females. During the 2004 East Coast emergence, in many places at least two distinct cicada species were singing, and the differences between the two songs could be clearly heard. The overwhelming sound drives some people nuts, but to those of us sensitive to the cycles of nature and the majesty of natural events, it's a rare concert we're honored to experience.
At the left you see a close-up of a periodical cicada's face. Of course the round, red items are its compound eyes -- each compound eye composed of hundreds of tiny, simple eyes. Beneath the eyes you see two whiskerlike antennae, which the insect uses for feeling its way about. The face is somewhat triangular and at the pointed bottom of the triangle you can see a sharp beak. This is to be expected since members of the Homoptera have mouthparts used for piercing. Homoptera don't chew, but rather stick their sharp beaks into food sources and suck up what they can.
Pay attention to when the periodical cicadas' concert begins ending. A few weeks after the droaning begins, when the adults have mated and the eggs for the next generation have been laid, the adults begin dying. They fall from the trees, flutter for a while, and then simply die, to be consumed by cats, ants, or whatever your neighborhood has. You can't see anything wrong with them. It's as if they simply run out of energy, and maybe that's what happens.
available at Amazon.com
Cicada Sing-Song (ages 9-12)
Cicadas (ages 9-12)
Cicadas and Aphids: What They Have in Common (ages 9-12)
When the Woods Hum (ages 4-8)
When the adults were dying during my last periodicale-cidada experience I was living in a trailer and for a while the sound of their falling onto the trailer's top was constant throughout the day, maybe one a minute. You couldn't walk around without squashing them.
Though the cicadas making such a fuss along the US eastern coast in 2004 were on a 17-year cycle, every year we can hear cicadas -- but not always as loudly as during 2004 along the East Coast. That's because many strains exist, and they have different, often overlapping cycles. Annual cicadas appear yearly. In my part of the world, southwestern Mississippi, the main periodical cicadas are on a 13-year cycle, not a 17-year one. I have seen some dwarf strains half the size of regular cicadas. Really, cicadas are fascinating and wonderful insects!