Sometimes the best cicada locations are just a short distance from your home. This summer I came across a grove of pine trees that had two species of Neotibicen: Neotibicen linnei (Linne’s Cicada) and Neotibicen canicularis (Dog-Day Cicada). Neotibicen linnei and Neotibicen canicularis look very similar when they’re adults (appearances vary by location), so it helpful to compare the two species.
This image compares Neotibicen linnei and canicularis when they’ve recently molted (teneral). Note that the N. linnei is yellow and green, while the N. canicularis is a pink/salmon color.
This image compares these cicadas approximately 24 hours after molting. Note that they’ve achieved their adult coloring, which is very similar, but you can see vestiges of the pink on the N. canicularis.
This last image compares the wing shape of N. linnei (foreground) and N. canicularis (background). Both cicadas are standing on the same piece of white paper. The wings of the N. linnei have a sharper bend — see how the tip of the wing is lifted far off the surface of the paper, while the wing of the N. canicularis almost sits on the paper. Also note that the N. linnei is a more vibrant green, and the N. canicularis is more of a drab/olive green.
Read this journal article, to learn how closely these cicadas are related genetically:
HILL, KATHY B. R., DAVID C. MARSHALL, MAXWELL S. MOULDS, & CHRIS SIMON. “Molecular phylogenetics, diversification, and systematics of Tibicen Latreille 1825 and allied cicadas of the tribe Cryptotympanini, with three new genera and emphasis on species from the USA and Canada (Hemiptera: Auchenorrhyncha: Cicadidae).” Zootaxa [Online], 3985.2 (2015): 219–251. Web. 20 Sep. 2017
You might notice that some cicadas have shriveled-up or otherwise damaged wings. Most of the time, wings become damaged during the molting process (ecdysis), specifically while their wings harden (sclerotize). Their wings and body are most vulnerable when they are still soft.
Some reasons why a cicadas’s wings might not get the chance to inflate and harden:
If a cicada molts and its wings are not able to hang downward they won’t inflate with fluids and form properly.
Cicadas often trample each other in the rush to find a place on a tree to molt.
Harsh weather, like wind and rain, knock them to the ground or bend their wings when they’re soft.
Physical weakness or defects.
Just 10 Magicicada (American periodical cicadas) generations ago, the U.S. was mostly forest. Back then it was easy to find a vertical surface to molt on, or a plant stem to hang from. Today most forests have been replaced with agriculture, buildings, lawns, roads, sidewalks, parking lots, etcetera — so it has become increasingly difficult for periodical cicadas to find a good place to hang.
Magicicada can afford to lose a large number of their population due to wing malformations and other critical defects because there are simply so many of them — this loss falls in line with their predator satiation strategy.
However, if Magicicada cicadas lose too much habitat, they will go extinct (brood XI went extinct about 60 years ago). Lawns, roads, sidewalks, and other features of our human habitat create surfaces that are insalubrious for cicada molting.
In the video below, you will see a cicada molting. Note that its wings are able to hang downward and inflate to form properly shaped wings. If the cicada tried to molt on a vertical surface, the odds are its wings would be crumpled.
In the image below, there is a Neotibicen tibicen (not a periodical cicada) that sclerotized (hardened) before completely shedding its nymphal skin.
Although adorable, this Neotibicen will never sing or fly.
One of the most frequently asked questions we receive is: “what do cicadas do“? This question is similar to the question “what is the purpose of cicadas” — the answers to both questions help people understand why these fascinating, unusual creatures exist at all.
The simplest reduction of their life cycle is:
1) They hatch from an egg.
2) They burrow underground where they will drink from plant roots for most of their lives.
3) They leave the underground and become adults.
4) The males make sounds that attract females.
5) Males & females court & mate.
6) Females lay fertilized eggs in the branches of plants, and the cycle continues.
7) They die.
The specifics of a cicada’s life cycle varies from species to species, but here is a more detailed view of what cicadas do:
From egg to 1st instar nymph:
1) Cicada nymphs hatch from eggs.
2) Nymphs feed on plant fluids which they access thanks to the egg-nest groove made by their mothers.
3) They leave the groove, and drift to the ground. Their descent to the ground doesn’t hurt them because they weigh so little.
4) Once on the ground, they dig into the soil until they find small rootlets, from which they will feed.
5) Underground, they will tunnel/dig…
6) and establish a cell…
7) from where they’ll comfortably feed. Cicadas feed on the xylem sap of plants. With the help of bacteriathey transform the water, minerals and amino acids found in tree fluids to the tissues of their own bodies.
8) They pee, in fact they seem to use excess plant fluid to moisten soil to help mold the walls of their cells.
9) Throughout their life underground they will move from root to root… as plant root systems change with the seasons, when roots die off, or perhaps to avoid predators.
10) Underground, a cicada may (depending on the species) go through four instars, molting three times (see an image of the four instars).
Preparing to emerge:
11) Cicadas will build a tunnel to the surface of the ground, in preparation for their emergence.
12) Cicadas often take that a step further an build a chimney/turret above ground. This often happens in shady areas or when the ground is muddy.
Once above ground:
13) They emerge from their tunnels…
14) Cicadas run as fast as they can…
15) And find a surface perpendicular to the ground, hold tight, and begin to molt…
16) During the molting process (ecdysis), cicadas perform many acrobatic moves to separate themselves from their nymphal skin, including pulling their old trachea from their bodies.
17) Once outside their nymphal skin, they will inflate their wings…
18) … and expand various parts of their bodies, like their heads.
19) They will change color.
20) Once their bodies are hard enough (sclerotization counts as a thing they do)…
21) They will either seek shelter, perhaps by crawling up higher along a tree trunk…
22) or if your are a Magicicada, you might stick around in the hopes that a predator will eat you.
Mating and Reproduction:
23a) If you are a Male cicada, you are going to sing… unless you belong to a species that cannot sing, in which case, you’ll move your wings in a way that will produce a sounds.
There are many types of songs: a) distress calls, b) calls to establish territory, c) calls to attract females, d) including choruses of many cicadas and e) courting calls
23b) Female cicadas, and some male cicadas, move their wings to make sounds, also in an effort to attract and engage a mate.
24) Most cicadas (aside from Magicicada during the early days of their adult lives) will try to avoid being eaten by predators.
25) They’ll fly, of course.
26) Cicadas, like Magicicada, will establish chorusing centers, which are places where the male cicadas sing together and females come to meet them.
27) Male and female cicadas will court…
28) and mate…
29) the female cicada will lay her eggs in grooves (ovipositing) she etches into a suitable plant stem, and we’re back to step 1.
30) The last thing cicadas do, of course, is die, and return the nutrients found in their bodies to the soil, where they will be broken down and absorbed by the plants they fed upon.
Some things cicada do not do:
Here are some things cicadas do not do:
1) They don’t seek shelter during the fall months (i.e. they don’t try to live inside your house), unlike Ladybugs or Stinkbugs.
2) They don’t sting or otherwise pass venom onto people.
3) They don’t chew plant leaves, like caterpillars or grasshoppers.
4) They don’t dump garbage in the ocean.
Cicadas “eat” / drink something called xylem (sap), which is a watery tree fluid containing amino acids and minerals. Cicadas drink rather than eat.
People probably ask “what do cicadas eat” because they are afraid that cicadas will eat their flowers and garden fruits and vegetables. Cicadas lack mouthparts that can chew and swallow vegetation. Your tomatoes and marigolds are safe.
How does a cicada drink xylem? The cicada’s mouth parts (aka rostrum or beak) are in the shape of a straw, which can pierce rootlets, roots and branches.
The labium form the outside of the beak of the cicada; inside the labium is the stylet which is comprised of the mandibles and maxillae, which the cicada uses to pierce plants and drink their sap.
The labrum connects the labium to the rostrum…
The rostrum, or what people call the “nose” of the cicada, contains enourmous pumping muscles (1) that suck the xylem up into the cicada.
The cicadas’s polymerized, viscous saliva plugs up any holes their mouth parts create (2), so a root will not continue to leak xylem when the cicada moves on to a new root. They put the cork back in the wine bottle, so to speak.
Cicadas are able to derive nutrition from the xylem thanks to bacterial endosymbionts that live in the cicada’s gut.
Cicada are known for drinking xylem from tree roots (as nymphs) and branches & twigs (as adults), however, when they are small they must rely on grasses, and possibly other small plants for nourishment.
Young cicada nymphs are smaller than a grain of rice when they first begin feeding so the tiny roots of grasses are the best fit for their small beaks.
Grass roots are likely the first roots a young cicada nymph will encounter, as they are close to the surface.
Deciduous trees shed their rootlets in winter months, but grasses do not (2). This is not an issue in tropical regions.
Perhaps the reason why periodical cicadas are “attracted to woodland edges and exposed aspects, especially for chorusing and ovipositing” (1) is their offspring will be more likely to find the roots of grasses in those areas. Young nymphs would be unlikely to find suitable tiny roots deep in a shady forest.
Once the cicada nymph is larger, they can burrow to larger and more permanent tree roots, and feed on there.
It is interesting to note that not all cicadas feed on trees. Some feed on sugarcane, which is a giant grass (we’re back to the grasses again). The Brown sugarcane cicada (Cicadetta crucifera) and Yellow sugarcane cicada, (Parnkalla muelleri) of Australia feed on the sugarcane plants and cause damage to plants.
1The Ecology, Behavior, And Evolution Of Periodical Cicadas, Kathy S. Williams and Chris Simon, Annu.Rev. Entomol. 1995. 40:269-95
2Xylm Feeding by Periodical Cicada Nymphs on Pine and Grass Roots, With Novel Suggestions for Pest Control in Conifer Plantations and Orchards, Monte Lloyd and Joann White, OHIO J. SCI. 87 (3): 50-54, 1987
More than a few people have asked Cicada Mania: “do cicadas pee”? Absolutely, cicadas do pee. There are a couple of reasons why:
They pee to eliminate excess fluids taken in while drinking xylem (1).
They pee to eliminate non-essential amino acids (2).
Underground, they could use excess fluid to help moisten and remold their tunnels & cells (2).
They might, in some cases, even use it to keep ants from attacking… (3)
You may have been under a cicada-filled tree on a sunny day and felt a sprinkle or two. Don’t worry, it is just watery tree sap (xylem) passed through a cicada.
A detailed explanation of the experience courtesy of Les Daniels:
I’ve experienced this several times where I was on the receiving end of this artificial rain. When many cicadas congregate on warm days, they feed on the tree fluids and often urinate ‘piss’ while doing so. This bug urine is called ‘honeydew.’ The little buggers have pelted me several times while I was observing a little ‘too’ close. It isn’t uncommon. Lastly, the ‘honeydew’ does not stain or stink. In fact, it feels like raindrops.
Some cicadas seem to pee more than others, for instance, the Chremistica umbrosa of South-East Asia. If you walk under an umbrosa, you will need an umbrella! (The Latin root of both words, umbr means shade). Here is a video of Chremistica umbrosa:
1Records Of The Cicada, Chremistica Umbrosa (Distant, 1904) In Singapore, With Accounts Of Its Mass Emergence (Homoptera: Cicadidae: Cicadinae), Tzi Ming Leong, Aminurashid and Benjamin P. Y-H. Lee, NATURE IN SINGAPORE 2011 4: 163–175, 15 June 2011
2The Ecology, Behavior, And Evolution Of Periodical Cicadas, Kathy S. Williams and Chris Simon, Annu.Rev. Entomol. 1995. 40:269-95
3 The documentary The Queen of Trees by Deeble & Stone features a segment about Fig Cicadas, that expel pee, sweet with the phloem sap of the fig tree, which is enjoyed by ants and monkeys, which has the side benefit of keeping those predators and nuisances away.
Yes, cicadas can see. People might assume that cicadas cannot see because they are slow to move when approached or are easy to capture.
Cicadas have 5 eyes. Two large compound eyes, which are used to visually perceive the world around them, and three small, jewel-like, simple eyes called ocelli. We believe the ocelli are used to perceive light & darkness. The fact that there are three of them, arranged in a triangle, may help them triangulate the direction of the sun or the movement of a shadow.
The reason they are easy to capture right after they have molted is that their body parts are not hardened and ready to react quickly. The reason they are easy to catch once their bodies are hardened is often that they want to be caught, due to a species survival strategy called predator satiation (more on that in a future article).
No. When many types of cicadas first emerge from their nymphal skin they are white in color. Gradually, their bodies become a darker color. Some take longer than others to change. Some die before the change can occur, and their corpses remain white.
This is a photo of a teneral (soft) Magicicada:
Its skin will eventually turn black and orange.
The are some cicadas, like the Tibicen pruinosus fulvus Beamer, 1924, that retain their lighter, teneral colors, but they are not albinos. Note: fulvus means yellow.
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Update: John Cooley shared his thoughts about this article about the Hodgkinia symbionts. There is a lot more work in this area of research yet to be done.
Update: McCutcheon (Matthew A. Campbella, James T. Van Leuvena, Russell C. Meister, Kaitlin M. Carey, Chris Simon, and John P. McCutcheon) has a new paper that shows Magicicada may have between 20 to 50 variants of Hodgkinia in their gut! Read the paper here. It would seem that the longer the life cycle, the more variants of Hodgkinia will be present in cicadas.
Here is the species used in the study: Magicicada tredecim:
From the October 5th, 2014 post:
Most people know how termites rely on microbes in their gut to break down the wood they consume into nutrients their insect bodies can use. Even human beings benefit from bacteria to help digest certain carbohydrates, fight pathogens and produce certain vitamins (like K and B12).
Cicadas also benefit from microbial endosymbionts. Cicadas, for most of their lives, consume a diet of xylem sap, drawn from the roots of trees. There are two types of sap: xylem and phloem. Phloem is the delicious, sugary one — in Maples, it’s Maple Syrup. Xylem is the “Diet” version of that. Thankfully cicadas have bacteria in their gut that process the xylem sap into nutrients cicadas can actually use.
Recently it was discovered that one such bacteria (Hodgkinia) has become two distinct bacteria in some cicadas belonging to the genus Tettigades. This discovery was documented in the paper Sympatric Speciation in a Bacterial Endosymbiont Results in Two Genomes with the Functionality of One by James T. Van Leuven, Russell C. Meister, Chris Simon, John P. McCutcheon (link http://www.cell.com/cell/abstract/S0092-8674(14)01037-X).
What’s interesting is the Hodgkinia bacteria became two distinct species for no particular discernible reason (nonadaptive evolution). Separate, either of the species would be useless to the cicada because they produce an incomplete set of nutrients, but together they produce the compete set of nutrients. Two function as one, that once was just one. Ed Yong does a thorough job of explaining this on National Geographic. According to Yong’s article McCutcheon thinks they know how it happened (explained in the article and paper). Why it happened is another matter — of course how and why might be the same thing deep in the soggy bowels of a cicada.
Chris Simon, let me know that she is working on a paper that will discuss bacteria found in Magicicada. It will be interesting to learn what they find in the bellies of those long-living cicadas.
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