15 Fun & Interesting Facts about Cicadas
Cicadas are a family of winged insects of the order Hemiptera. They’re widely present all over the world, but their peculiar lifecycle still has us confused to this day. These bugs are known for a lot of things, but much of the popular knowledge about them is steeped in misconception.
Let’s clear up some of those misbeliefs today! Whether you’re an insect enthusiast or not, I’m sure you’ll find some of the following facts interesting.
1. Not All Are Created Equal
There are over 3,000 documented Cicada species in the world. Not only that, but Cicadas exist everywhere on the planet, except for Antarctica. It’s obvious that there’s going to be lots of variety between different species.
The overwhelming majority of Cicadas on the planet emerge annually in spring. But did you know? There are only seven species of periodical Cicadas in the world, and all of them belong to North America.
The seven rarest species in the world are the “Magicicada septendecim”, “Magicicada cassinii”, “Magicicada septendecula”, “Magicicada tredecim”, “Magicicada neotredecim”, “Magicicada tredecassini”, and “Magicicada tredecula”. Unlike any other group of Cicadas, periodical Cicadas are truly unique, because they only emerge once a decade.
2. Some Species Are Endangered
Periodical Cicadas are the rarest on the planet. Then, it’s no surprise that these species are most likely to be endangered. According to the IUCN Red List of Threatened Species, the “Magicicada septendecim”, “Magicicada cassinii”, and “Magicicada septendecula” species are all near threatened.
While the IUCN doesn’t mention any population trends for these species, many researchers have already noted dwindling numbers and changes in emergence patterns. Brood XI and XXI are already extinct, while Brood VII and X have been on a steady decline.
Periodical Cicadas are sensitive to environmental cues, especially when it comes to rising temperatures. Due to climate change and increasing average temperatures in recent years, many periodical cicadas have started emerging off-cycle. Such is the case for the species Magicicada neotredecim. This former 17-year cicada now emerges in a 13-year cycle.
3. Cicadas Are Herbivores
Cicadas are herbivorous insects, which means they only consume plants. Many people believe that Adult Cicadas don’t eat at all, but that’s a misconception. Adult Cicadas don’t have a voracious appetite. They also don’t cause much, if any damage to the plants they feed on. That’s partly due to their anatomy and diet.
Cicadas don’t have mouthparts for biting and chewing, but they have other ways to get nutrients into their bodies. Cicadas have a long, beak-like tube extending from their face. This body part is called a “labium”. The extremity of the labium contains four small, sharp stylets.
Cicadas use their labium to pierce through the surface of plants and to suck up plant fluids. Basically, Cicadas have a built-in straw they use to sip on trees and plants. Unlike other insects which away at plant leaves and stems, Cicadas only feed on small quantities of plant sap. When Cicadas aren’t feeding, the labium is hidden away.
4. A Fungus Infection Can Make Them Explode
Not all is easy for the peaceful, buzzing Cicada. These insects are susceptible to a very threatening fungus, called the “Massospora cicadina”, which infects roughly 2-5% of Cicadas in the US. When the Cicadas are ready to emerge, fungus spores settle on their abdomens, where they start spreading and eating away at the insect’s body.
As the fungus continues growing and multiplying inside the cicada’s body, it reaches a point where the insect’s lower body bursts open. Sometimes, the entire lower body falls off, including sexual organs. But that’s not all! It gets worse. This fungus also hijacks the Cicada’s brain, altering its mating behavior. Male Cicadas start imitating female mating calls to lure in more male Cicadas.
When other males are tricked into mating with an infected Cicada, the fungus spreads to them as well. Of course, males can also spread the infection to female Cicadas too. Oh, and even after the sexual organs fall off, Cicadas still feel the urge to mate. Nature sure has a twisted sense of humor.
5. They Have Many Predators
Speaking of the Cicada’s life hardships, these guys also have lots of predators to worry about. Cicadas don’t have any poison or venom or other ways to defend themselves. They’re also fully herbivorous, which means they don’t come into contact with many viruses and bacteria from carcasses or other insects. As a result, they’re edible for just about anyone and anything.
Because they swarm in such large numbers, they become an easy target. First, there are other insects, such as wasps, spiders, mantises, fire ants, robber flies. Then there are animals like birds, bats, squirrels, and other rodents, snakes, lizards, raccoons, opossums, and even fish.
Even domesticated pets like cats and dogs will have a go at them. But that’s not all! Even humans can eat Cicadas, which brings me to the next point.
6. They’re Safe to Eat
Cicadas are a great source of nutrition and not just for other insects and small animals. Yes, that’s right! You can eat them too if you want! Some people already do. Cicadas are a popular ingredient for some regional Chinese cuisines, for example.
According to the FDA, Cicadas are completely safe to eat, as long as you don’t have a shellfish allergy, or are pregnant or lactating. Those who’ve tried say that Cicadas have a subtle sweet and nutty flavor.
They’re also supposedly crunchy and meaty when fried or baked. Many compare the taste to shrimp or thinned asparagus. So, if that’s your thing, you can enjoy this protein-packed bug as a flavourful snack.
7. Cicada Adults Can Fly (Very Badly)
Cicadas have long, translucent wings. They can indeed use them for flying, but their stocky bodies might become disadvantageous. Cicadas are infamous for being extremely clumsy fliers.
Whether it’s the disorganized trajectory or the fact that they frequently run into obstacles, Cicadas just aren’t that good at using their wings.
They rarely fly higher than 500 feet, and they don’t fly for longer than it takes to find a branch to hang onto. Cicadas are such bad fliers that many people have the misconception that these poor guys are blind. But according to a 2015 study, Cicadas are indeed able to see, albeit only 15 centimeters ahead of them.
8. They Swarm Together for Survival
One single brood is made up of billions of Cicadas. It’s truly a sight when they all emerge together. Turns out, there’s a good reason for swarming in such high numbers. This behavior is a natural survival strategy known as “predator satiation”.
Since Cicadas are vulnerable to predators, they need other ways to keep their population safe. Well, when a species is so abundant, predators become satiated quickly.
This satiation compels them to abandon their hunt early on. This way, they don’t make a large dent in the prey’s numbers. That’s how Cicadas ensure their survival by outnumbering their predators.
9. Cicadas Are Very Loud
Cicadas make deafeningly loud sounds. In fact, their song reaches up to 120 decibels, which is as loud as a thunderclap or a chainsaw, except that it lasts for hours on end. Males are by far the loudest members of the species. They generate their loud cricket-like noises using a membrane on their skin called the “tymbal”.
Male Cicadas actually have two distinct sounds. One of them is for repelling predators, while the other is for a mating call. Females are quieter, as they lack the tymbal organ. They don’t sing at all. Instead, female Cicadas produce softer sounds by flicking their wings.
10. They’re Beneficial for The Environment
Cicadas are often called locusts, but these two insects are quite different. In fact, the Cicada is everything the Locust wishes it could be. Locusts are annoying pests that devour crops and destroy vegetation.
Cicadas are the good guys that keep the environment alive. They prune trees, they aerate the soil, and when they die, their bodies nourish the soil with nitrogen.
Female cicadas tear small holes along tree branches, where they lay the eggs to hatch. When the young larvae come out of their eggs, they also start eating away at the branches to free themselves.
While this sounds damaging for the trees, it’s actually quite beneficial. As the tree branches start aging and drying, they’re ready to break off along these cuts. That’s how Cicadas naturally prune trees.
To aerate the soil, Cicada larvae spend a lot of time digging small tunnels underground. When they emerge in spring, they create holes on the surface. All this helps the air to circulate in and out of the earth. These small holes and tunnels also let the rain go deeper into the soil, nourishing the plants and trees.
11. Cicadas Have an Incredibly Long Lifespan
Think about house flies, fruit flies, or pantry moths. They only live for a few days at most. That’s lame. Now, beetles, mantises, and stick insects live for up to 2 years when kept in captivity. That’s a lot better, but still not the best.
How about Cicadas? Many species live for 2-5 years on average. But that’s not all there is to the Cicada. Some species actually live for 13-17 years! Now, that’s impressive. The “Okanagana synodica” Cicada can even live up to 19 years!
While Annual Cicadas have average lifespans of up to 5 years, Periodical Cicadas have some of the longest lifespans in the insect kingdom.
12. They Spend Most of Their Lives Underground
So, remember how Cicadas can live for close to two decades? Yeah, most of that time, they spend underground. After the eggs hatch and young Cicada nymphs fall on the ground, they start digging into the soil. There, they spend most of their long lives at a depth of around 12-18 inches.
They dig around and feed on plant liquids for 13-17 years. Then, finally, after almost two decades, they emerge from the ground to become the beautiful winged creatures we all know. Sadly, they only live for about four to six weeks as adults.
13. They Only Emerge in Specific Conditions
Cicadas emerge in Spring, usually in early or mid-May. However, they can also emerge earlier or later than that, depending on environmental factors. In the past years, some Cicadas also emerged during late April. What determines their mass emergence is soil temperature.
When the soil reaches 64°F, the Cicadas know that the weather above the ground is warm enough to support breeding. Once they sense the soil temperature climbing up, they start digging their way out. The mass emergence usually takes place in the evening, soon after the sun sets.
14. They Get Confused Easily
Much to our amusement, Cicadas are very easy to trick. Because the mating call of male Cicadas is so loud, it sounds very similar to a power tool. Female cicadas often mistake the sound of land mowers and other loud machinery for a mating call. They’re often seen swarming to such devices.
Cicadas landing on humans is also a common occurrence. Apparently, Cicadas will mistake anything tall enough that’s standing upright for a tree. As Eric Day, an entomologist at Virginia Tech stated in an interview for Mashable, “Cicadas land on people because they strongly resemble trees.”
15. We’re Not Sure How Their Internal Clocks Work
We know that some Periodical Cicada species emerge every 13 years, while others emerge every 17 years. One major factor which triggers their mass emergence is soil temperature. But one question leaves scientists scratching their heads. How exactly do Cicadas keep track of the passage of time?
Many researchers now hypothesize that Cicadas calibrate their internal clocks with the help of additional environmental cues. A major one is the changes to the flow and quality of tree root fluids.
When the host tree blooms, the fluids within the roots contain more sugar and protein than throughout the rest of the year. So, perhaps Cicada larvae use the seasonal cycles of trees to tell how much time has passed.
Did I miss anything? If you have any other facts that I did not cover in this article, please write a comment below.