Cicadas are making the news again, which means that things are about to get much louder if you share a backyard with these insects. Cicadas are winged insects that lay dormant for years at a time, then all wake up together with one purpose… to breed. However there are several things about cicadas that make them special, so in this article we’re going to learn some interesting facts about cicadas. Some of which you may find quite surprising.
Let’s have a look!
18 interesting facts about cicadas
Cicadas have been all over the news and social media where I live because a large brood is back for the first time in 17 years. I’ve been doing some research about them out of curiosity and decided to put a list of the facts I found together for everyone. I found out some very interesting things about cicadas.
1. There are 15 broods of cicadas on record
There are 3 broods of the 13 year life cycle cicadas, and 12 broods of the 17 year life cycle cicadas. They are labeled with roman numerals Ⅰ – ⅩⅤ. At the time of writing this in 2021, brood X is about to awaken. The difference in life cycle length has something to do with the time needed for the cicada to mature in the ground.
2. Adult cicadas only live 4-6 weeks before they die
A cicada’s life cycle is more complex than most animals, and is broken up into 3 stages: eggs, nymphs, then adults. Cicada eggs hatch in only about 6 weeks after being laid by an adult female, and the adults themselves only live 4-6 weeks before dying. However the cicada nymphs can live underground eating roots and preparing for the day that they rise to the surface, for 13-17 years.
3. The cicada shells on trees are left behind by the nymph
When the nymph emerges from the ground, it looks for somewhere that it can shed it’s uncomfortable shell and enter its adult phase. This is often on a tree, but can also be on the side of a house or other structure. This shell is called the “nymph exoskeleton” and can take 5-6 hours for the insect inside to work its way out.
4. Female cicadas are silent, we hear the male’s mating call
It’s true, the female of the species is actually completely silent, it’s the male cicadas making all the noise. Each species of cicada has it’s own specific mating call, recognized by the females of that species, that’s meant to attract mates to each other.
5. Brood X cicadas are seen every 17 years
The last time we saw brood X in the United States was in 2004, before that 1987, and now they’re back in 2021 which is every 17 years. The next time we see them will be in 2038. They usually emerge from the ground sometime in late April or early May.
6. The great eastern brood of cicadas has the largest range and population
The great eastern brood, aka brood X, is the by far the largest brood of cicadas. Brood X ranges throughout 15 states including Indiana, Pennsylvania, Maryland, New Jersey, Delaware, Tennessee and other areas in the eastern United states. In some places there may be as many as 1.5 million cicadas per square acre, so we’re talking trillions of insects appearing at once.
7. There are 2 classifications of cicadas: periodical and annual
Periodical cicadas spend 13-17 years underground as nymphs, annual cicadas will only spend around 2 years in this form before they come to the surface. However, once they do arise their purpose is the same. Mate, lay eggs, then find a good place to die.
8. Cicadas and locusts are 2 different insects
While cicadas are sometimes referred to as locusts, and both are swarming insects. However these arthropods are actually completely different. Locusts belong to the same family of insects as grasshoppers, while cicadas are more closely related to leafhoppers, which are different.
Locust swarms are known for being much more harmful than cicadas. A swarm of locusts can strip away all vegetation in an area in no time, there are even biblical mentions of locust plagues. Cicadas are generally thought of as much less harmful and more annoying.
9. You can actually eat cicadas
Many cultures eat cicadas, and some people right here in the U.S. eat them as well. I’ve heard mention of them being in the shrimp family and tasting similar, but I’ve also heard the taste of a cicada compared to popcorn. So while they are apparently edible, do you really want to eat something thats been in the ground for 17 years? That’s gonna be a hard pass from me dog.
10. The sound of cicadas can reach 100 decibels
If there’s one thing we think of when we think of cicadas, it’s the incredibly loud noise. Some species of cicada can make sounds that reach up to 120 decibels which is equivalent to a loud rock concert. It’s that loud. Crickets make their noise by rubbing their wings together so many people think that cicadas do the same. The truth is that cicadas actually have a special organ called a tymbal that they can flex to create their mating call.
11. Cicadas are not blind
There is a myth that cicadas are blind, but this is not true. Cicadas actually have 5 eyes that are used to watch for predators and make sure they live long enough to fulfill their destiny of mating and dying. It’s unclear how keen their vision actually is, but they see well enough to get by.
12. Cicadas are most active in the day
If you’ve ever wondered if cicadas make noise at night, then you’ll be happy to know that most cicadas climb up in the trees and are pretty quiet at night. It’s from dawn to dusk, meaning all day long, that you’ll hear the males screaming for some recognition from the females. At least we’ll get some sleep at night though right?
13. There are 3 species of cicadas in brood X
Brood X has 3 species of cicadas living on the same schedule. As I mentioned, each will have it’s own separate mating call and mate with females of it’s own species. They all look quite similar so we’ll leave it to the entomologists to tell them apart.
3 species of cicadas in brood X:
- Pharaoh cicada – Magicicada septendecim
- Cassin’s periodical cicada – Magicicada cassinii
- Magicicada septendecula
14. Adult cicadas don’t eat very much
Most of the eating is done in the nymph state of their life cycle. Once an adult cicada emerges from the discarded exoskeleton, they really do not require much in the way of food. Cicadas are herbivores and may feed on various plant fluids, but according to some sources adult cicadas do not need to feed at all in the 4-6 weeks they live.
15. Cicadas do not bite or sting
They can look a bit intimidating with their big read eyes, large wings, and scary noise, but cicadas are harmless to humans. Rest assured, cicadas do not bite and they do not sting nor are they poisonous or venomous in any way. Just leave them alone and you’ll be fine.
16. Cicadas are actually beneficial to the environment
I mentioned that aside from the noise, cicadas are virtually harmless. We’ll take it a step further and say that cicadas are actually beneficial to their ecosystems in several ways. Here are a few examples.
Benefits of cicadas:
- Cicadas are a great food source for any insectivorous animal
- They help prune mature trees of their growth
- Cicada aerate the soil when the nymphs burrow underground
- Their bodies serve as a source of nitrogen for the trees
17. There are over 3000 species of cicadas
There are over 3000 species of cicadas in the world. Just 7 species are periodical cicadas, the kind that live underground for 17 years. There are four 13-year cicada species and three 17-year cicada species. The annual species of cicadas are found all over the world, but the periodical species are unique to North America.
18. Females lay 200-400 eggs
A cicadas adult life consists of emerging from the nymph shell, searching for a mate, and then if you’re a female, laying eggs. After the cicadas have successfully mated, the female will soon lay her eggs in a tree branch somewhere. She will die long before the eggs hatch in 6-10 weeks. Once hatched, the nymphs drop down to the ground and start the life cycle over.