8/13/09

dog-day cicada emerges

This summer I watched an annual or "Dog-day" cicada transform from a nymph to an adult. The entire process took about an hour and a half.

Folklore says that, "When you hear the first song of the dog-day cicadas, the first frost is just six weeks away."

Emerging from its nymphal skin

Stretching out its wings.

Resting on its nymphal skeleton. Stretching out its wings a little more.

Its wings are almost all the way extended.



Its wings are almost dry and ready to go. Soon after this cicada flew off.

A description of the "Dog-day" cicada from the University of Kentucky.

"Cicada nymphs develop underground, feeding on root sap of various trees and shrubs. The nymphs are generally pale brown, rather hunch-backed, and have stout forelegs they use to dig through soil. The life history of species found in Colorado is poorly understood. Development likely takes between two to five years to complete.

Cicadas go through a simple metamorphosis with egg, nymph, and adult stages. After emerging from the ground during summer months, cicadas quickly mate and the females insert eggs into small twigs on living trees using a knife-like ovipositor (egg laying structure). When nymphs hatch from the eggs, they burrow into the soil where they feed underground on the juices of plant roots. During growth and development, the nymphs shed their skins several times as they get larger. After several years (1-3 years for most annual cicada species and 13 or 17 years for many of the periodical cicada species) the nymphs emerge from the soil, climb onto tree trunks, then shed their skins a final time to become winged adults. Adult cicadas produce hitch-pitched, droning noises. These courtship songs help male and female cicadas find one another, and each species has its own distinct song."


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