Are Cicadas Dangerous? Uncovering the Truth Behind These Insects

Cicadas are large, noisy insects that emerge periodically and can be found in various parts of the world.

As their presence becomes more noticeable, many people tend to wonder if these insects pose any threat to humans, pets, or the environment.

Are Cicadas Dangerous

The good news is that cicadas are not dangerous to humans or pets. They do not bite or sting, and pose no harm to household gardens or crops.

In fact, the only potential damage they can cause is to young trees when they lay eggs in twigs, but this can be easily managed by covering trees with appropriate mesh or netting.

Are Cicadas Dangerous for Humans?

Bites and Stings

Cicadas are not known for being dangerous to humans. They do not possess the ability to bite or sting.

In fact, they are not venomous or poisonous, making them safe for consumption by many organisms, including humans and pets.

Pros:

  • No bites or stings
  • Not venomous or poisonous

Cons:

  • None

Noise Levels

Cicada mating calls are known to generate loud courting sounds. They have been reported to reach noise levels ranging between 90 and 100 decibels.

To provide some perspective, here’s a comparison table of different noise levels:

Noise SourceDecibel Level
Normal conversation60 dB
Vacuum cleaner70 dB
Cicada mating call90-100 dB
Lawnmower90 dB

Note that excessive exposure to noise levels above 85 dB may cause hearing damage.

Impact on Daily Life

Overall, cicadas have very little direct impact on humans. Some people may be temporarily disturbed by their loud sounds or find their red-brown eyes and red eyes aesthetically unappealing.

However, these insects do not have any lasting negative effects on humans or their daily lives.

For instance, their presence in gardens or yards typically does not cause noticeable harm or damage to trees and plants, even though they feed on trees.

AKA Green Cicada

Characteristics of Cicadas:

  • Loud courtship sounds
  • Red-brown eyes
  • Red eyes
  • Feed on trees with minimal damage
  • Harmless to humans

Cicadas and Their Effects on Pets

Dangers to Dogs

  • Cicadas do not bite or sting
  • Not poisonous or venomous

Cicadas are generally harmless to dogs. If a dog happens to eat a few cicadas, there’s no need for concern.

However, if a dog consumes a large number of cicadas, it may cause an upset stomach or even vomiting1.

Dangers to Cats

  • Cicadas are not dangerous to cats
  • Possible upset stomach or vomiting if consumed in large quantities

Similar to dogs, cicadas don’t pose a serious threat to cats. Cats may show curiosity towards cicadas, and if they happen to eat a few, there’s no need to worry.

Eating a large number of these insects could lead to an upset stomach or vomiting in cats1.

Table showing the impact of eating cicadas in pets

PetsPoisonousUpset StomachVomiting
DogsNoPossiblePossible
CatsNoPossiblePossible

The Impact of Cicadas on Plants and Crops

Cicadas are large plant-feeding insects known for their loud, shrill noise and discarded exoskeletons that cling to vegetation1.

Adult cicadas don’t damage plants directly by consuming their leaves, but they harm plants inadvertently by laying eggs into small branches2.

Damage to Garden Produce

Although cicadas are not known to be harmful to humans, pets, or household gardens3, the damage they cause can affect some garden produce.

When female cicadas lay eggs, they cause branch tips to split, which can lead to aesthetic damage to established trees and occasionally the death of saplings4.

Cicadas can damage a variety of plants and vegetation, including:

  • Young trees
  • Flowering plants
  • Small shrubs

Protection and Prevention Measures

To protect your plants and crops from cicadas, consider implementing prevention measures like netting. Netting with ¼ inch mesh can be placed over young shrubs and saplings to prevent female cicadas from laying their eggs on them5.

Comparing prevention methods

MethodProsCons
NettingEasy to use, effective for young trees & shrubsCan be unsightly, not reusable
Insecticidal SprayCan target cicadas specifically, safe for plantsMay be harmful to beneficial insects, needs reapplication

By using these protection and prevention methods, you can minimize cicadas’ impact on your plants and crops during their emergence period.

Cicada Life Cycle and Behavior

Cycle Stages – Nymphs to Adults

Cicadas begin their lives as eggs laid by female cicadas on tree branches. They then hatch into larvae and fall to the ground, where they burrow into the soil1.

These larvae, called nymphs, go through several stages of development, called instars, before becoming adults2. Each molting of their exoskeleton allows them to grow larger2.

Nymphs typically take 2-5 years to reach adulthood2, with periodical cicada species spending 13 or 17 years underground1. Annual cicadas, on the other hand, complete their life cycle in just one year3.

  • Periodical cicadas: 13-17 years
  • Annual cicadas: 1 year

Comparison table of periodical and annual cicadas

 Periodical Cicadas1Annual Cicadas3
Life cycle length13 or 17 years1 year
Emergence patternDistinct broodsAnnually
Mating seasonSpringSummer
Call frequencyHighLower

Adult cicadas have characteristic black bodies, large red-brown eyes, and membranous wings with orange veins1. Once they emerge, they begin their loud and buzzy courtship display1.

Mating and Reproduction

Male cicadas begin courting by producing loud mating calls14. These sounds are created by vibrating a drum-like organ at the base of their abdomen4.

Female cicadas, however, are silent and signal their interest by flicking their wings4. After finding a mate, the males die and the females proceed to lay eggs on tree twigs1.

Cicada Species in the United States

Various cicada species are found across the United States5.

Among the most well-known are the periodical cicadas, which emerge in distinct broods1. Brood X is one such group, which emerged during spring 20216.

Cicadas are generally harmless insects1. Even their underground nymph stages are not disruptive to soil or crops1. In fact, they may even contribute to soil aeration and fertility7.

Cicadas as Food for Predators

Birds and Cicadas

Cicadas, like grasshoppers and locusts, are insects that birds often snack on in nature. However, entomologists have observed that birds seem to have a particular preference for cicadas.

They are a great source of nutrition for various bird species. They have an abundance of protein that birds find highly beneficial.

Some examples of birds that feast on cicadas include:

  • Blue Jays
  • Crows
  • Woodpeckers

Other Predators

Cicadas are not only preyed upon by birds but also by various other predators. A few examples include:

  • Small mammals like squirrels and raccoons
  • Reptiles, such as snakes and lizards
  • Large insects, including praying mantises

Comparing cicadas with grasshoppers and locusts

FeatureCicadasGrasshoppersLocusts
AppearanceLarge winged insectsLong, slender insectsSimilar to grasshoppers, but larger
SoundLoud, buzzing noiseChirping or clickingSoft, chirping sound
PredatorsBirds, mammals, reptiles, insectsBirds, mammals, reptilesBirds, reptiles, mammals

Evidently, cicadas serve as an important food source for various predators in the ecosystem. Both birds and other types of predators enjoy the protein-rich snack that cicadas provide.

Periodical Cicadas

Dealing with Cicadas: Expert Advice

Entomologists at the University of Connecticut assert that cicadas are harmless to people, plants, and property. They are active from July through September, and no control methods are necessary.

Pesticide Usage

Pesticides are generally ineffective in controlling cicadas, and their usage is discouraged.

Experts believe that the natural predators and the cicadas’ short life cycle are enough to keep the population in check.

Alternative Methods of Handling Cicadas

  • Netting: Cover young trees with ¼-inch netting to protect them from egg-laying female cicadas.
  • Timing: Since cicadas emerge every 13 to 17 years, residents in the eastern U.S. can plan tree planting and other landscaping activities accordingly.

Pros and Cons of Alternative Methods

MethodProsCons
NettingProtects young trees from egg-laying cicadasMay be unsightly, requires periodic maintenance
TimingAvoids damage to trees and plantsRequires knowledge of cicada cycles, long waiting periods

Conclusion

The apprehensions surrounding the danger posed by cicadas are largely unwarranted.

These large insects, though noisy and conspicuous during their emergence, are not a threat to humans, pets, or the environment. With no ability to bite or sting, cicadas are harmless to both humans and pets.

While their mating calls can be loud, they don’t have lasting negative effects on daily life. Their impact on plants and crops is minimal, and even the potential damage to young trees can be mitigated through simple preventative measures like netting.

Cicadas are an essential part of ecosystems, contributing to soil fertility and serving as a crucial food source for various predators.

As they periodically emerge, their presence reminds us of the intricate connections within nature, while emphasizing their harmless coexistence with our world.

Footnotes

  1. Cicadas | US EPA 2 3 4 5 6 7 8 9 10 11 12 13 14
  2. https://hort.extension.wisc.edu/articles/cicadas/ 2 3 4
  3. https://www.epa.gov/safepestcontrol/cicadas 2 3
  4. https://agcrops.osu.edu/newsletter/corn-newsletter/12-2021/are-periodical-cicadas-threat-field-crops 2 3 4
  5. https://www.ars.usda.gov/news-events/news/research-news/2021/some-things-to-consider-for-2021-periodical-cicada-season/ 2
  6. https://www.ars.usda.gov/news-events/news/research-news/2021/some-things-to-consider-for-2021-periodical-cicada-season/
  7. https://www.megaphonewriting.com/blog/cicadas

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Cicada from Malaysia: Tacua speciosa

Subject: Unidentified beetle or fly
Location: Kuala Lumpur, Malaysia
March 23, 2014 11:57 am
Hello bug lovers,
I caught this photo of a bug that looks like a fly which is as big as a tree sparrow. I first taught it was a bird who got trapped in my condo which is on the 16th floor. Its wings is wide and has striking orange veins. Which from a far looked like a bird and one would assume that since its on the 16th floor.

So i wanted to help it find the openings to freedom but it kept flying low down the wall on the floor and beneath the sofa. So i decided to capture it first which was difficult cause i was a bit frightened by the size. I finally caught it in a container ( dont worry i didnt hurt the guy not even a scratch) then i took photos of it.

I got worried since it decided not to move anymore after it got caught but it was only playing dead. Then i released it on the ground floor of my condo. It flew away really quick but it looked majestic. From the photo i took you can see its bright green neck.

The only sound it made was from flapping the wings. Hope you can identify it for me b ecause this is the first time ever ive seen it. It is a really beautiful insect, you shouldve seen it fly with its wings spread wide and bright. I live in a condo which is in the heart of the city, Kuala Lumpur.
Signature: Danial

Cicada:  Tacua speciosa
Cicada: Tacua speciosa

Dear Danial,
This gorgeous insect is neither a beetle nor a fly, but rather a Cicada.  It is
Tacua speciosa, and there are several images on Cicada Mania

According to Cicada Mania:  “The Tacua speciosa is a beautiful cicada native to Malaysia, Indonesia, Borneo, Sumatra, and other countries & islands in the Malay Archipelago” and it “is one of the largest cicadas.”  Though you did not hear any sounds, Cicadas are among the loudest of all insects.

Cicada:  Tacua speciosa
Cicada: Tacua speciosa

Letter 2 – Cicada Metamorphosis

Extra Dogday Cicadas This Year?
Hello,
Just stumbled upon your site while trying to find out if this year there is an extra brood of dogday cicadas in the mid-Atlantic, specifically Maryland? I don’t remember in recent years hearing the dogdays so loud and being so numerous. I was able to capture a few pics of one emerging this morning and are attached to this e-mail.

These are nice and close. AOL may ZIP them. Let me know if you can’t see them. You may use them as you wish, just maybe drop me a line! I have slightly larger versions as well. Look for my next e-mail with two absolutely FABULOUS shots, if I do say so myself, of the Brood X buggers from last year….
Alex

Hi Alex,
Thanks for the image. We are posting it as well as your Periodical Cicada image.

Letter 3 – Cicada Metamorphosis

EXTROVERT
I had sent you this photo on 8-2-2005 and am sending it again now (8-5-2005). Is it not good enough to put on your site? Please reply to Michael Blevins
(08/02/2005) I took this picture early morning June 6,2005 at my home in Sotsylvania county Virginia.

The subject was on the front tire of my 1969 Volkswagen “Bug.” How strange is that ? I suppose this little guy or girl was drying it’s wings after emerging from it’s shell. I call this photo “Extrovert” as in coming out of your shell. I had seen hundreds of cicadas and shells over the years but had never seen them together. Your site is a gem.

I found it as a link from an Earthlink newsletter I get. Keep up the good work !!!
Mike Blevins.

Hi Mike,
The reality of the situation is that we did like your photo and did plan to post it. On a busy day, we might get 100 letters. It takes us about an hour to post four letters. We cannot post nor respond to every letter.

We are not getting paid to run this site. It is something we enjoy doing in addition to our fulltime job, home chores, daily routines and various and other sundry pleasures and obligations. Mom is currently on her yearly visit and arrived the day your letter did, which is limiting our online time allotment.

In the general scheme of things, waiting four days for a response is not out of the ordinary. In these days of virtual mail, instant gratification has become an expectation instead of a pleasure. We apologize for any inconvenience our tardiness has caused you.

We have taken the liberty of removing your image from the frame you provided as it did not agree with our site’s aesthetic. We also changed the orientation of your image to maximize its size. If that is a problem let us know and we will remove the image. Have a nice day.
P.S. Your cicada is an Annual Cicada in the genus Tibicen. The Periodical Cicadas, Magicicada species, must wait 17 years underground for maturity.

Letter 4 – Cicada Metamorphosis

cicada pictures
first, thanks for the site! good info and great pictures. I thought I would share these with you. we recently found a cicada in the process of hatching, the pictures of it only halfway out of the shell have gone missing but we do still have these that show it on the shell.
the cord in the picture is a standard outdoor extension cord about 3/8 of an inch in diameter.

Thank you for your beautiful photos documenting metamorphosis of the cicada. They will greatly enhance our cicada page.

Letter 5 – Cicada Metamorphosis,

THANK YOU BOTH !
I want to thank you for all the help you have provided me over the last few years. Haven’t heard of me? That’s because I have been a lurker on your site for years.

You have provided countless answers to questions for found bugs and critters with all the previous answers to the questions of others. You are also helping us alter my 7 and 5 year olds from “stomp first, and ask questions later” into “catch and releasers.” It’s hard being a dad and having to know all the answers to questions without people like the two of you.

I do know a lot about bugs and insects, but on many occasions I am stumped. I even go on your site for fun to scroll through all the cool images. I actually can’t go on line without them wanting to visit your site.

Any way here is a photo of a newly emerged cicada in the spirit of the changes you will be going through on your site. Taken today in South Jersey. We checked on him/her through out the morning until it was there no more. Fare thee well !
ReallyJustaDad

Dear Dad,
We’ve got to begin by stating that Just (in all its forms) should never be used to describe noble roles. We are thrilled that you have crossed the line from being a lurker to an interactive reader.

We have gotten numerous images of Cicada Metamorphosis in recent weeks, but neglected to post them for various reasons. Since we are officially into the Dog Days of Summer, it seems appropriate to post your lovely image of an Annual Cicada or Dog Day Harvestfly.

There is another exoskeleton of a metamorphised nymph visible in the lower right corner of your photo. We are strong supporters of change and look forward to many changes in the coming months.

Letter 6 – Cicada Metamorphosis

Two bugs found in Alabama — Need ID
Fri, Jun 19, 2009 at 9:20 PM
I was walking around tonight in my apartment complex, and I found these two bugs. Right now, it’s technically still spring, but the weather is very warm and balmy right now.

The pictures are as good as I could get it. They are very slow moving, and they didn’t seem to mind posing for the pictures. The one in front (brown) is shorter. It seemed to be about 1-1.5 inches. The other one has a slight green tint to the wings and seems to be 1.5-2 inches length in the body and another 1/2 inch or so for the wings.

At first when I found them, the larger one was on top of the brown one. I didn’t disturb them or harm them in any way whatsoever. I just want to know what the little things are. I would appreciate ANY help!
Amanda
Jacksonville, AL

Cicada Metamorphosis
Cicada Metamorphosis

Dear Amanda,
You have observed a Cicada metamorphosis.  This is not two bugs, but one winged adult Cicada emerging from its shed larval skin. 

We are unable to identify your exact species, but we can tell you that this is one of the Annual Cicadas that appear in a given location yearly.  It often takes three years for the nymphs to develop underground, but each year there is a new adult population.

Letter 7 – Cicada Head: What has been decapitating Cicadas????

Crazy looking… beetle?
Location: Southern Illinois
October 28, 2010 8:17 pm
My sister took a picture of this insect that was sitting on her car this fall. She didn’t provide any details on its behavior or size. It’s certainly unlike any insect I’ve ever seen, and I can’t even pinpoint whether it’s a beetle or some other classification! Help me out please!
Signature: Erik S

Cicada Head

Dear Erik,
This is the third photo we have received in recent months of a Cicada Head and we would love to know what has been decapitating Cicadas.  We suspect birds have eaten the fatty portion of the insects body and left the head behind.

Letter 8 – Cicada Metamorphosis

Subject: Unidentified Bug – Cicero, NY
Location: Cicero, New York
July 11, 2013 5:36 am
Good morning,
Thank you for taking the time to view my question and photo. Attached is a photo of a bug and it’s cocoon, this is the second day in a row that the bug has hatched on the side of our garage door – in the exact same spot.

On July 10th, the hatchling was noticed around 7:30 am and remained in the same place until it moved up into a corner of the garage door frame. The wings started as clear and then turned darker in color until it flew away near dusk (approx. 7:30 pm).
Any assistance is appreciated!
Signature: Natalie

Cicada Metamorphosis
Cicada Metamorphosis

Dear Natalie,
This is the metamorphosis of an Annual Cicada.  The immature stages or instars of the Annual Cicadas are found underground where the nymphs take nourishment from the roots of trees and shrubs.

  When the time to metamorphose into an adult is at hand, the nymph climbs to the surface, climbs up a tree or wall and molts for the final time.  The adult Annual Cicada flies off leaving the exuvia or shed skin behind.  Annual Cicadas are sometimes called Dogday Harvestflies.

Thank you so much!  I thought that is what it was but wasn’t positive.  Have a great day!!  J
Natalie

Letter 9 – Cicada Metamorphosis

Subject: Strange Bug
Location: Western North Carolina
June 25, 2015 9:12 pm
I stepped outside my home and found this incredible looking insect clinging to one of the porch columns. The photographs aren’t great but it really threw me off because its appears to be a brown beetle-looking bug but with a very disproportionate green protrusion arching out of its back.

The green part looked like its very own bug as nothing about its aloe plant-like body matched the brown bug it was coming out of but I’m almost positive its just one insect. The green part even had very convincing yet almost comically big yellow eyes that I imagine are part of an overall camouflage defense mechanism but its so freakish its like when parasitoid fungi bloom out of insects in the forest. All this aside, what bug is this?

I couldn’t find any pictures in a couple nc entomological databases that I searched. I live in Lincoln county North Carolina. I hope you can shed some light on this, many thanks.
Signature: JD

Cicada Metamorphosis
Cicada Metamorphosis

Dear JD,
You are quite lucky to have witnessed the metamorphosis of a Cicada.  The Cicada has been living underground as a wingless nymph and now that it has shed its nymphal exoskeleton, the adult Cicada will fly away once its wings have expanded and hardened.

Letter 10 – Cicada Metamorphosis

Subject: green-winged bug coming out of exoskeleton
Location: Lexington, MA
July 5, 2015 9:19 am
Dear bugman,
We found this bug attached to my 7-year-old’s butterfly garden we had left outside after freeing butterflies that we had watched grown from caterpillars. The bug is big, about 2 inches. It hasn’t yet moved after emerging from its exoskeleton.
We live in New England.
Can you tell us what it is?
Many thanks.
Signature: Paula

Cicada Metamorphosis
Cicada Metamorphosis

Dear Paula,
This is a wonderful image of the metamorphosis of an Annual Cicada.

Letter 11 – Cicada Metamorphosis

Subject: What the heck, HELP.
Location: Northern California
May 19, 2016 9:07 am
I’ve lived in Northern Ca all my life and never seen something so strange and scary looking. What the hell is it?
Signature: Kimberly

Cicada Metamorphosis
Cicada Metamorphosis

Dear Kimberly,
This is not a scary event.  You were lucky to have witnessed the metamorphosis of a Cicada.  The nymph has been living underground, feeding on fluids sucked from the roots of plants.  As the nymph neared maturity, it dug to the surface where it molted for the last time, emerging as a winged adult.

Letter 12 – Cicada Metamorphosis

Subject: What is this?
Location: Southern NH
August 23, 2017 1:31 pm
Can you please tell me what this is? Thanks!
Signature: Brian

Cicada Metamorphosis

Dear Brian,
Congratulations on witnessing the metamorphosis of an Annual Cicada.

Letter 13 – Cicada Metamorphosis

Subject:  No wings but looks like a wasp…?
Geographic location of the bug:  Cupertino, CA
Date: 04/03/2018
Time: 03:48 PM EDT
Your letter to the bugman:  Found this in my weedy front yard in the shade. At first I thought it was a large bee, but I don’t see any wings. And then I thought it might be a spider but I only see 6 legs.

What in the world is this?  Sorry I don’t have anything for scale in the photo. I’d guess it was about the size of my fingernail.
Thanks!
How you want your letter signed:  Rena

Cicada Metamorphosis

Dear Rena,
You observed the metamorphosis of a Cicada.  The nymph has been living underground feeding on roots, and as it neared maturity, it dug to the surface, climbed the plant upon which you observed it, split its skin and emerged as a winged adult. 

You did not notice the wings as they had not yet expanded and hardened.  The pattern on the nymph resembles this nymph on BugGuide of a Platypedia species.

Letter 14 – Cicada Metamorphosis in Borneo

Subject:  What ciacada species is this?
Geographic location of the bug:  Borneo, Sabah
Date: 04/24/2018
Time: 03:34 AM EDT
Your letter to the bugman:  Hi there, please help me identify the cicada species.
How you want your letter signed:  gurveena

Cicada Metamorphosis

Dear gurveena,
Your images illustrate the metamorphosis of two Cicadas, and we cannot even state for certain they are the same species as they are in different stages of the process.  Furthermore, they have not yet hardened after transformation and they have not yet assumed their final coloration.

  Perhaps one of our readers more versed in the Cicadas of Borneo will be able to provide more conclusive identifications.  Your images are awesome.

Cicada Metamorphosis

Letter 15 – Cicada in Manhattan

Subject:  NYC Exotic or Neighbor’s Luggage Jumper from….?
Geographic location of the bug:  Lower Manhattan, New York City
Date: 07/13/2018
Time: 08:07 PM EDT
Your letter to the bugman:  Hi!
Season: July/Summer
Location: NYC
This is the best shot I could get — I don’t have a great shot of the head area but you can see part (the “bugged” out eyes) and the coloring in brown on the body and green on the wings.
Thanks for running this site and fielding questions like mine.
How you want your letter signed:  Downtown Prof

Cicada

Dear Downtown Prof,
This is an Annual Cicada, an insect that is sometimes called a Dog Day Harvestfly because they are most numerous during the Dog Days of Summer and they look like a giant Fly. 

It would not be unusual to find Cicadas in Manhattan as the lifetime of an Annual Cicada nymph is spent underground drawing nutrients from the roots of trees, shrubs and other plants, and even Manhattan has street trees and parks.  When it nears maturity, the Cicada nymph digs to the surfaces, molts for the last time and emerges as a winged adult Cicada. 

Cicadas are full of nutrients and even fat, and they are a valuable source of food for wildlife, and with the current trend in entomophagy, Cicadas are even relished by humans, especially when Periodical Cicadas appear after 17 years underground.  Perhaps the Annual Cicadas most fascinating predator is the Cicada Killer, a large wasp that paralyzes the Cicada and buries it where it will feed the young of the Cicada Killer. 

Adult Cicada Killers are vegans that take nectar from flowers, and their sole meal as a larva is a paralyzed Cicada.  Perhaps you will be lucky enough to witness a Cicada Killer with its prey in Manhattan

Dear Daniel,
Thanks so much! I used to live in Morningside Hts…(Columbia U) …much greener up there. But, I live off a private University park at NYU and I bet that’s why I got the visitor. And following your insight about importance to wild life, a pigeon was stalking the cicada from the terrace next door.
You must get some great stories (or tedious ones like mine!).
Great site!
Best,
Kat

Authors

  • Daniel Marlos

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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