Kids' Cicada Hunt!

Hunting for Periodical Cicadas in 2007:

When Will We Find the First Periodical Cicadas of the Year?

We use this page to tell the story of our hunt both for Periodical Cicada nymphs and for the first adult Periodical Cicadas to emerge in our neighborhood.  The page is arranged like a journal, with entries ordered by time (oldest first). 

Periodical Cicada Home 

Cicada Hunt 2007 Photo Stories 

Things to Do This Spring 

Kids afraid of bugs?

Cicada Citizen Science

Cicada Hunt 2003 Photo Story 

Local Cicada Exhibits 

Local Cicada

Cicadas in the News 

Cicada Books

Cicadas on the Web 

Tracking Use of Cicada Websites 


Click below here to read about:

FIRST CICADA NYMPH (but not a Periodical Cicada) 
Sunday, April 1, 2007

FIRST CICADA BURROWS (probably by Periodical Cicadas)
Sunday, April 8, 2007

MORE BURROWS (cicada or not?)
Saturday, April 14, 2007

Sunday, April 29, 2007

Sunday, April 29, 2007

Wednesday, May 2, 2007

Monday and Tuesday, May 14-15, 2007
Please go to our CicadaBlog to read this story

Please go to our CicadaBlog to see what we've been up to!




FIRST CICADA NYMPH (but not a Periodical Cicada)
Sunday, April 1, 2007

Today we found our first live cicada nymph of 2007.  Unfortunately, we’re 
pretty sure it was an annual cicada, not one of the periodical cicadas that 
we are hunting for this spring. 

Here’s what happened.  My wife had asked us to dig up some perennial
plants from our front garden, which is under the canopy of a 75-year-old 
elm tree (see photo, below).  
Our front yard, in south Oak Park, Illinois.

But first, we turned over some of the rocks that surround the plantings.  
We found lots of earthworms and beetle larvae (like those in the photo, 
below).  We also found millipedes, pillbugs, and ground beetles.
Ethan turning over rocks in search of worms, bugs, and cicada nymphs.  Earthworm and beetle larva in Ethan's hands.

But there were no cicada nymphs under the rocks.  As we started to dig, 
we found lots of shed skins from last summer's annual cicadas, sitting 
on top of the soil (see left photo, below). 

Shed skins of annual cicada nymphs left over from last summer. We could tell they were from annual cicadas because periodical cicadas' shed skins are smaller and narrower.  In the photo below, the periodical skins are on the left and the annual skins on the right.
Comparison of shed skins of periodical cicadas (on the left) and annual cicadas (on the right).  Penny is for scale.

Finally we found some cicada nymphs in the soil, but they turned out to 
be mummified.  They had died without emerging.  Then their bodies had 
somehow dried out (or maybe freeze-dried).  The mummies survived, 
partly decayed but uneaten by scavengers, until we found them.  
(Photo of the mummified nymph is below.)
Mummified annual cicada nymph dug out of the soil.

And then, as we were digging under some of our garden rocks, we found 
a live cicada nymph!  It was very pale, more yellowish than brown.  However, 
it was also the same shape and size as the annual cicada nymphs we find 
every summer.  (Photos are below.  In the photo on the left, the live nymph 
is still in the rounded hole in the soil where we had found it.  In the photo on 
the right, the live nymph is on the left and the shed skin of an annual cicada 
is right beside it.)
Live cicada nymph still in the rounded hole in the soil where we had found it.  Live cicada nymph is on the left and the shed skin of an annual cicada is on the right.

Maybe our live nymph tried to emerge late last summer and didn’t make it 
(perhaps because of the rocks that covered the soil there).  Or maybe 
the live nymph was getting ready to emerge later this summer.  But we are 
pretty sure that it is NOT a periodical cicada nymph working its way to the 
surface for this spring’s emergence.

So, our hunt continues….


FIRST CICADA BURROW (probably by Periodical Cicadas)
Sunday, April 8, 2007

On Easter morning, we drove north to Glenview, Illinois, to celebrate the holiday
with the Gyllenhaal side of our family.  While waiting for dinner, the boys and I 
went exploring in the small woods across the street from my sister’s house.  We 
started turning over logs, and with the fourth log, there they were:  Possible 
periodical cicada burrows.

Overview of the small woods where we found the burrows.   Ethan turning over a log and pointing to a burrow.

Three burrows with rings of mud around the entrances, The holes were openings from 
deep vertical tunnels, a bit smaller in diameter than a dime.  That’s the right size for the burrows of at least one kind of periodical cicada.  

Most of the burrows under the logs had a ring of mud built up around the entrance, reaching a half centimeter or so above the surface.

Some of the mud was still wet, as if the burrows were freshly dug. 

Looking around the woods, we found more burrows among the dead leaves.  
Most of these burrows had rounded mud caps covering the entrance.

Possible cicada burrow with mud cap.  Dime shows size of burrow.

Another possible cicada burrow with mud cap.  Dime shows size of burrow.

The articles and Web pages we’ve read talk about how periodical cicada 
burrows are often topped off with “mud chimneys,” “mud tunnels,” or 
“turrets” of dried mud.  These mud features all seem to have an opening 
at the top.  Check the following pages for photos that others have taken of 
these features:  (Look 
     about 2/3s of the way down the page. We found mud caps in similar 
     positions at the edges of logs, but ours were sealed shut)  (See the “mud tunnel” photo. This 
     is much taller than what we saw, although the surface texture is similar.)

The dried mud covering our burrows was more like rounded caps than 
chimneys or turrets.  Our mud caps had no openings at the top.  So, we 
did NOT find an exact match for any periodical cicada burrow we’ve seen
on the Web.  But then, conditions on April 8 were pretty different from when 
the Web photos were taken.  We found the at least five or six weeks before 
the cicada emergence is expected around here.  Also, it has been cold for 
the last several days, even below freezing in the mornings. 

If these really are periodical cicada burrows, maybe the mud caps are a way 
to protect cicadas in the burrows from the cold, or from rain, or from predators 
while the nymphs wait until emergence time.

Oh, one more thing.  In the week or so before emergence, the cicada nymphs 
are supposed to lurk in the tops of their burrows.  We didn’t see a single 
nymph today – just the burrows.

So, the hunt continues....


MORE BURROWS (cicada or not?)
Saturday, April 14, 2007

On Saturday, April 14, the boys and I were bird watching along the west side 
of the Des Plaines River, just south of Joliet Road.  (We think this is in Lyons, 
Illinois.)  While walking through a thicket just west of the park road, we noticed 
lots of holes in the dark, muddy floodplain soils.  The holes were openings of 
deep burrows.  They were about the same size as the burrows we found on 
Easter Sunday
(smaller than a dime).  However, these burrows did not have 
mud caps (like the Easter burrows) or mud chimneys (like many periodical 
cicada burrows have).   Here's what they looked like:

A burrow with no walls, but with a bit of a mud lining.  Dime shows how big it is. A burrow with low mud walls around it.  Dime shows how big it is.

As you can see above, a few burrows seemed to have mud linings that were 
a slightly different texture than the surrounding soil (on the left), and a few had 
just a bit of mud built up on their edges (on the right).  Below, you can see a 
burrow with crumbly soil at the edges (center of photo), as if something had 
tried to dig down into it from the surface.

Several burrows, with a dime for scale.  The burrow in the center had crumbly margins, as if something had been digging into it.

So, were these periodical cicada burrows?  Crayfish?  Something else?  We’re not 
sure.  They don't fit the classic descriptions of periodical cicada burrows.  I guess 
we will check this area again in a week or two and see if the burrows have changed.

By the way, we also flushed a woodcock in this thicket.  Woodcocks are birds with 
long beaks, which they poke into the ground to find worms and other soil animals to 
eat.  Go here to learn more about the American Woodcock.  This got us wondering.
Maybe the woodcock had been sticking its bill down these holes, trying to fish out 
whatever was in there. 

So, the hunt continues....  And we will be watching for hungry woodcocks as well as
cicada nymphs.


Sunday, April 29, 2007

Over the previous week or so, we had been hearing reports of other folks digging up
Periodical Cicada nymphs in their gardens.  So, on Sunday, April 29, we decided to 
try digging in our garden.  We found one and a half cicada nymphs (don’t ask…).  
Below are photos of the live nymph we found (next to a dime for size comparison):

Cicada nymph, most likely of a periodical cicada, dug up in our garden on April 29, 2007.  Cicada nymph, most likely of a periodical cicada, dug up in our garden on April 29, 2007.

This nymph SEEMED smaller, a bit narrower, and redder than the Annual Cicada 
nymphs we have dug up before.  Unfortunately, we could not find many confirmed 
photos of Periodical Cicada nymphs that were dug up early, before their bodies 
got darker in color.  Here is one such link:

Fortunately, Roy Troutman saw the photo on our blog and used the comment section
to correct our preliminary identification.  He said it was most likely one of the Annual 
Cicadas (scientific name Tibicen) rather than a Periodical Cicada (scientific name 
Magicicada).  He based his identification on the overall shape and the lack of color 
in the eyes (which should be turning red by this point in their lives).

We vowed to dig again in a few days and see if we can find the real thing.

If you have been following along with our hunt for Periodical Cicadas this year, you 
may remember that we first tried digging for Periodical Cicada nymphs back on 
April 1.  However, that day all we found were Annual Cicada nymphs that appeared 
to be left over from last summer.  Go here to read about our finds on April 1.

So, the hunt continues....  


Sunday, April 29, 2007

Lots of websites and newpaper articles state that Periodical Cicada nymphs 
will emerge, all at about the same time, when their body temperatures reach 
certain point. (Various sources say that point is 63, 64, or 65 degrees Fahrenheit.) 
If that's true, then we should be able to take the temperature of the soil in our 
yard, and then predict when the nymphs will start to emerge in our area. Given 
our try-it-yourself spirit at Kids' Cicada Hunt, we just had to try taking the 
temperature of the soil ourselves.

So, about 1 p.m. on Sunday, April 29, we got a large thermometer (designed for elementary school classrooms) and buried it in the soil that we had dug up looking for nymphs. (See photo below, dime shows the real size.)

Thermometer partly buried in our garden, used to take the soil temperature on April 29, 2007.

We took the photo after about 20 minutes, when the soil thermometer read 
about 62 degrees Fahrenheit.  After 40 minutes, the temperature was down 
to about 60 degrees.  Unfortunately, we had to give up at that point. We don't 
know if the temperature would have continued to fall.  Next time we will leave 
the thermometer buried for at least a couple of hours.

The air temperature was about 78 degrees at that point, so the soil was much 
colder than the air.  According to what we had read in the newspapers and 
elsewhere, the soil temperature was too cold for the cicadas to emerge, even 
though the weather above the soil was warm and beautiful.

Now, there are lots of reasons to think our method would produce temperature 
readings that were a bit too high.  For instance, the soil had sat in the sun for a 
few minutes during digging, and when we packed it around the thermometer, 
there were still lots of small air spaces where the warm surface air could leak 
down around the thermometer.  So, to check ourselves, we went to Spectrum 
Technologies' Cicada Watch 2007 website: 

Spectrum has installed professional quality soil thermometers in the soil at 
Naperville and Plainfield, Illinois, which are about 25 to 30 miles southwest of 
our town of Oak Park.  Their readings for Sunday, April 29, were about 64 
degrees degrees at Naperville and 55 degrees at Plainfield.  Because we are 
closer to the still-very-cold Lake Michigan, we would have expected our soil 
temperatures to be a bit lower than the Spectrum Technologies thermometers. 
Instead, we seem to be right in the middle, between two sites with rather different 
soil temperatures.  (The Naperville site seems to be consistantly warmer than the 
Plainfield one.)  So, we are wondering if cicadas will emerge earlier in Naperville 
than in Plainfield, and if our yard will fall somewhere in between?

We wanted to know how scientists found out that that temperature was the key to 
cicada emergence, so we went on a kind of science scavenger hunt.  We used 
Web searches to find the actual scientific research study behind all the quotes 
in newspapers and on the Web.  In 1995, cicada scientists Kathy Williams and 
Chris Simon published a wonderful (but very technical) article describing what 
scientists have learned about Periodical Cicadas. You can link to their article 
from this page (go down to paper number 22): 

Williams and Simon wrote about the research done on cicada emergence. They 
wrote, "After examining photoperiod [day length], air and soil temperatures, slope 
[angle and direction a hill faces], and sun exposure, Heath [1968] concluded that 
periodical cicada emergence may be triggered when soil and cicada body 
temperatures at a certain depth reach a critical value" (p. 272-273).  The research 
mentioned in this quote was by James Edward Heath:
Heath, J.E. (1968). Thermal synchronization of emergence in periodical "17-year" 
     cicadas (Homoptera, Cicadidae, Magicicada). American Midland Naturalist, 80, 

Dad read a copy of Heath's paper, which he obtained from a university research 
library.  The paper described how Heath studied the emergence of cicadas in 
southern Ohio in 1965.  He measured air temperature and soil temperature at 
various depths, plus he found a way to measure body temperatures of cicada 
nymphs that had just emerged from the ground.  The body temperatures of the 
emerging nymphs were almost all between 63 and 66 degrees Fahrenheit.  This 
was about the same as the soil temperature at about 8 inches depth.  Like any 
good scientist, Heath phrased his conclusions carefully:  "The most consistent 
feature of the thermal environment during emergence was soil temperature.  The 
body temperatures of emerging cicadas matched closely the temperature at about 
20-cm [about 8 inches] depth.  Some temperature characteristic at a 15-25-cm 
depth in the soil may synchronize emergence" (p. 445).  So, Heath didn't pick a 
particular temperature as "characteristic of that depth," although his data suggested
it was from 63 to 66 degrees Fahrenheit for the cicada nymphs he studied.

Because we want to know when our Chicago-area Periodical Cicadas will emerge, 
we will keep an eye on soil temperature using the Spectrum Technologies website. 
Also, we probably will stick our own thermometer in the ground a few more times 
this May.

So, the hunt continues....  And we will be watching soil temperature so we know 
when to intensify our search for emerging cicadas.


Wednesday, May 2, 2007

We've been hearing more reports of both Periodical Cicada nymphs and their 
burrows from folks in nearby towns.  (Go here to read some of them: )

We were getting jealous, so we went digging in our front garden again on 
Wednesday afternoon.  This time Ethan found a REAL Periodical Cicada nymph.  
We could tell it was a Periodical Cicada because it was relatively longer and 
narrower than Annual Cicada nymphs, and it had dark red eyes.   We also found 
an Annual Cicada nymph, so we took a photo of them together (below).  The 
Periodical Cicada nymph is on the left, and the Annual Cicada nymph is on the 
right.   (There is also a dime in the photo, so you can tell how big they really are.)

Periodical Cicada nymph on left, Annual Cicada nymph on right.  Dime shows how big they really are.








Both nymphs will have darker bodies when they finally emerge.  The Annual Cicada nymph also will grow larger, and its eyes will turn dark brown. 

We also found a bit of broken mud chimney from a Periodical Cicada burrow.

A photographer from our local Oak Leaves newspaper was there taking pictures as we dug.  She captured this image seconds after Ethan found the first nymph, and it was published on the front page:

Oak Leaves photo showing Ethan holding our first Periodical Cicada nymph of 2007, while Aaron and Dad watch.
You can read the whole story here :,OP-Cicadas-050907-S1.article  

So, the hunt continues....  But now we are looking for the first adult cicada!

Monday and Tuesday, May 14-15, 2007

This story is still being written.  The first draft is on our CicadaBlog.
Please go to our CicadaBlog to read this story


Please go to our CicadaBlog to see what we've been up to!



Click here to return to our main Periodical Cicada page

The following links take you to pages about Annual Cicadas:

        Copyright 2004-2007 Eric D. Gyllenhaal                                                                                       Search this Site

        Cicada Hunt! is part of the Salt the Sandbox Web. 
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          This page was created on April 2, 2007, and it was last updated on May 20, 2007.