The Periodical Cicada - Part II: The Amazing Life Cycle of the Periodical Cicada
When considering the world’s most amazing natural phenomenon, we must include the life cycle of the Brood X periodical cicada in the discussion. There is not anything quite comparable to it. I think my neighbors would agree, but whether or not they like it is another thing. But I digress.
The cycle commences when adult females of the previous hatch deposit between 400 – 600 eggs in several slits they make on tree branches. After six weeks, the eggs hatch and the inch-long nymphs drop and burrow into the ground, disappearing from our view for 17 years.
During their underground lull, the nymphs go through five stages of development (during this time they are referred to as instars). To sustain themselves during this time, they feed by drinking xylem fluid from plant and tree roots.
After the conclusion of their 17-year subterranean residency, the cicada – still in a soft-body nymph stage – emerges, but only after the soil warms to 64 degrees Fahrenheit.
In moist soils, nymphs construct emergence chimneys of soil above the hole; in drier soils the ground will be peppered instead with dime-sized diameter holes. Either way, it’s a bit eerie to see these little alien-like creatures emerge from their passageways.
Once the nymph crawls out – the males emerge first – it climbs a tree trunk, grass stalk, or flower, and begins a final molt. At this stage, the insect measures about an inch long and is white in color and remains susceptible to a host of predators.
Within a few hours, the nymph sheds its exoskeleton, transitioning into the hardened black and orange body that strikes fear into the hearts of many humans. Within a few days the adult cicada can fly and thus, begins its mating ritual.
When male cicadas commence their buzzing calls and a female is interested, she responds with a wing flick, which then attracts the male, who flies toward her. If the female remains captivated with her suitor, they will mate tail to tail. Males mate several times, females only once.
After mating, females search for a tree branch – preferably a young sapling – where she lays her eggs. This is the stage where tree saplings can sustain damage. Mature trees also serve as egg deposit locations, but while some branches may be damaged and break from the tree, the older trees usually survive this periodical intrusion.
By June’s end the mating cycle is complete. Adults die with their bodies becoming a rich nitrogen source for the soil. A few weeks later the tiny nymphs hatch, drop to the ground, and burrow below the soil and the process starts once again.
After 17 years have passed, they come out and start yet another national sensation of fear and fascination. By that time, many humans have forgotten about them and thus begin their periodical anxiety of the 17-year periodical cicada. Short attention spans, those silly humans have.
In Part Three I’ll offer up a few photographic tips and techniques you can practice before the next emergence of the Periodical Cicada. And don’t worry, you’ll have 17 years to fine tune your cicada photography!
Periodical Cicadas (c) Jim Clark
Periodical Cicada (c) Jim Clark
Periodical Cicada (c) Jim Clark
Emergence Holes of the Periodical Cicada — look close and you’ll see some of the cicadas starting to crawl out! (c) Jim Clark