The Seventeen-Year Locust is back for summer 2016

Do you remember the crunch, crunch, crunch under your feet? Perhaps the annoying chirp all hours of the day? Maybe the feeling of an older sibling flinging that dried up, empty shell at you, causing it to get stuck in your hair? I know I remember.

That’s right, the 17-Year Locust is due back in our region this summer. The average student at SHU would have been between two and five years old the last time we saw these guys in full force. Fear not, readers, you’re about to get the full scoop on this super gross, but very fascinating bug phenomenon.

The 17-Year Locust or Periodical Cicada

Seventeen-year locusts are actually not locusts at all, but cicadas. Photo from dogonews.com.

Seventeen-year locusts are actually not locusts at all, but cicadas. Photo from dogonews.com.

Referred to as the 17-Year Locust, these bugs are actually Magicicada or Periodical Cicada. There is a theory that the reason we often call them locusts stems all the way back to the colonies.

Early American colonists had never seen periodical cicadas before since they do not emerge in Europe and supposedly mistook them for the Biblical plague of locusts. Some American Indians also thought this event had an evil significance. However, actual locusts are more like grasshoppers and not really related to cicadas.

Most periodical cicadas come to areas of North America in either 13 or 17-year cycles. Different broods of these bugs occur in different cycles and areas. The Cicada emergence coming to western Maryland, eastern Ohio, northern Virginia, southwestern Pennsylvania and pretty much all of West Virginia this year is known as Brood V.

We actually see, or hear, cicadas that are the cousin of these 17-Year Locusts every year. They occur in two to eight year cycles, but there is at least one brood every year. However, these are in much smaller numbers. It’s nowhere near the major nuisance 17 and 13-year cicadas can be.

When a particular brood of 13 or 17 years hatch and emerge, it is usually in millions of insects. However, the lifespan of a Cicada above ground is only about four to six weeks, so they are not around for long.

The Appearance of Periodic Cicadas
The vast majority of 17-Year Cicadas have red eyes, but they can also be gray, blue, white, yellow or multicolored.

Cicadas molt shortly after emerging from the ground. Photo by Gerald D. Tang from tangsphoto.photoshelter.com.

Cicadas molt shortly after emerging from the ground. Photo by Gerald D. Tang from tangsphoto.photoshelter.com.

The color of the bugs themselves depends on what stage of the lifecycle they are in. Prior to molting, nymph cicadas can be a tan or brown color. After molting, they are a very light brown or white for a while. This is when they get their wings.

In the last stage of life, fully mature Cicadas are dark brown. At this point, they are about an inch and a half long with reddish orange veins on their wings. The cicadas that are around every year are usually larger and black with green wing veins.

The Lifespan of 17-Year Cicadas

The cicada’s life span can be as long as 17 years, but all but just a few weeks of that time is spent underground. Cicadas first emerge in the nymphal stage and climb up trees to quickly shed their skin or molt.

After that, they are able to fly and mate. Shortly after mating, the male dies while the female lays eggs into small slits she cuts into trees. A female cicada can deposit up to 600 eggs over the span of her life.

After the eggs hatch, the tiny nymphs burrow into the ground. They survive by eating underground tree roots for years until it is their time to emerge.

When will they emerge?

While quite annoying, cicadas are not harmful to humans or animals. Photo from songsofinsects.com.

While quite annoying, cicadas are not harmful to humans or animals. Photo from songsofinsects.com.

The 17-year cicadas typically emerge in the late spring or early summer once soil eight inches below the surface gets to about 64 degrees Fahrenheit. This is the ideal temperature for them to start digging their tunnels to the surface.

After a few days with above ground temperatures in the high 70s or 80s and a little bit of rain, they’ll be here. The cicadas will emerge first in the sunny areas of your yard. They will also come out sooner the farther south you live.

There are multiple predictions and formulas online to calculate the cicada emergence in your area. In 2013, the emergence on the coast was delayed due to cold late-spring weather, so perhaps we will see a delay again this year.

Signs of Cicadas
There are several signs to watch for that may indicate the start of a cicada emergence.

First, you can look for little hills in the ground known as turrets or “cicada chimneys.” These are structures the cicadas build out of soil as they come to the surface. Secondly, look for holes about the size of a finger near the root system of a tree. This could be a sign that the cicadas will be using that tree to feed on and shed their skin.

Third, and most obvious, when the cicadas have emerged, you will surely hear them. Only male cicadas make this chirping noise, which comes from organs in their abdomen called tymbals. This can sound slightly different depending on the type of cicada, but it is something all male cicadas do. Females may also make a sound by flicking their wings to respond.

The Dangers of a Periodic Cicada Emergence

Some areas of the country will have millions of cicadas per acre. Photo from lipstickalley.com

Some areas of the country will have millions of cicadas per acre. Photo from lipstickalley.com

Posing no threat to humans or animals, cicadas do not bite or attack. At worst, they may fly into you by mistake as adults can be rather clumsy in flight. This can happen especially if you are using power tools or lawn maintenance items that make a buzzing noise as this can confuse them.

However, their diet poses a risk to young trees, bushes and shrubs. Cicadas eat only liquid juices that they suck from plants. Plants that don’t really need protection against cicadas include most flowers, herbs, vegetables, pine and firs. While damage may appear bad on adult trees, they usually survive after a year or two of looking sickly.

The best way to protect any particularly vulnerable plants is to buy ¼ inch pest netting to put around your plant. Insecticides are unfortunately ineffective on these large bugs.

Many animals including birds, cats and dogs eat cicadas. Fish enjoy them as well- you can even use cicadas as bait. In fact, some humans enjoy eating them, too! Look for all of your favorite cicada recipes online and give it a try if you are so inclined.

Good Luck this Summer
As if all of this wasn’t exciting enough, the 17 and 13-year cicadas are on schedule to co-emerge every 221 years. Luckily, we probably won’t be around to see it since the next one is in 2115.

Due to the large number of cicadas and the time-span of their lifecycle, it would be nearly impossible for any predator to cause cicadas to go extinct. As the longest-lived insect in North America, cicadas are sure to be around for a long time.

Cicada experts Alexander and Moore wrote in 1962, “The periodical cicadas make up a truly amazing group of animals; since their discovery 300 years ago, the origin and significance of their extended life cycles have been a continual source of puzzlement to biologists. Their incredible ability to merge by the millions as noisy, flying, gregarious, photopositive adults within a matter of hours after having spent 13 or 17 years underground as silent, burrowing, solitary, sedentary juveniles is without parallel in the animal kingdom.”

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