The Allure of Cicadas

This year, cicadas are re-emerging in many parts of the eastern United States. While not really locusts, they are considered a plague by some people. The Great Lakes Radio Consortium’s Jim Blum goes beyond the backyard to find out there is little to fear:

Transcript

This year, cicadas are re-emerging in many parts of the eastern United States.
While not really locusts, they are considered a plague by some people. The
Great Lakes Radio Consortium’s Jim Blum goes beyond the backyard to find out
there is little to fear:


(sound of cicadas)


Reporter Jim Blum: “I’m Jim Blum with naturalist Dan Best. Seventeen years ago this
month, Magicicada septemdecula and other species of periodic cicadas rose out
of the ground to lay eggs. Then, and now, and likely 17 years from now,
communities will expect a disaster. Dan, is it?”


Naturalist Dan Best: “No, I wouldn’t call it a disaster. Tremendous
natural phenomenon, yes, but disaster, no. Anytime you have large, big buzzy insects
around, people tend to get shook up, whether it’s bumblebees or dragonflies, but
especially when something shows up in prodigious numbers like these cicadas.”


JB: “Now, unlike a large outbreak of gypsy moths, the periodic cicadas don’t
actually eat the leaves.”


DB: “No, that’s right. The damage we are likely to see is the result of
female cicadas laying eggs.”


JB: “How?”


DB: “Well, they have a structure called an ovipositor, and in the end of a
twig they will use this like a little saw to make slits in the twig where they
will lay their eggs inside of that.”


JB: “How will that be apparent to us?”


DB: “Well, the twig will split as a result of several of these little egg laying
gouges in the twig, and from that point the twig may die, or the end of the
branch. And so you’ll notice withered brown leaves at the tips of branches.”


JB: “And that’s what they recognize as ‘flagging?'”


DB: “That’s the term.”


JB: “Now, what size trees are going to be affected?”


DB: “Branches or twigs that are half-inch in diameter or smaller. So on
big, mature trees that’s just the outer growth, no big deal. The trees
that are more vulnerable are the young trees, where literally all the
branches are that size.”


JB: “If this is not a disaster, what is it?”


DB: “I think it’s a tremendous natural phenomenon to experience. It only
occurs like a comet or a blue moon, and perhaps even less frequently than that.
You don’t want to miss it.”


(guitar music)


JB: “Now what’s a good time to see this emergence?”


DB: “Evening, just after dark. You’ll see the holes before the actual
emergence. And then, as they emerge, they’ll be coming up and you’ll see
them all over small trees. The edge of the woods is a good place to see
it.”


JB: “From the pictures I’ve seen, and from what I remember from 17 years ago,
the periodic cicada, bumblebee sized, black, orange eyes and wings. Do
they look like this when they come out of the ground?”


DB: “No, they don’t. What comes out of the ground are the nymphs, the
golden brown color, and no wings at all. Then they make their way up a tree
trunk or out on a branch, and this exoskeleton that they have splits open and
out emerges the adult which is a creamy white color with red eyes and a
couple of big black patches on it.”


JB: “Dan, are these cicadas going to be everywhere?”


DB: “Well, they are not going to be popping out of every square foot of ground in
the area, but there will be kind of a spotty emergence. But very heavy in
some places.”


JB: “If the visual spectacle of the emergence for some reason, doesn’t happen in my yard,
will I have missed out on the experience?”


DB: “No, because it’s almost impossible to escape what comes next.”


(sound up of cicadas)


DB: “The sound is an overwhelming, even annoying, series of buzzes and ticks.”


JB: “How do they make this noise?”


DB: “This loud noise is created by the males to attract the females. The
males vibrate two drum-like membranes to create the sound, which is then
resonated or amplified by a hollow chamber in their body.”


JB: “Not unlike the sound box of a guitar.”


DB: “That’s right.”


(strumming on guitar)


JB: “How long will we hear them?”


DB: “We’ll here this noise during the month of June and be over by about the
Fourth of July.”


JB: “About the same time that the annual or dog days cicadas show up.”


DB: “That’s right, that we’ll here during the hot days of July and August.”


JB: “Now why are those called annual cicadas?”


DB: “Well, unlike the 17-year cicada, which emerges from a single brood in
our area, we have several broods of these annual cicadas which have a much
shorter cycle in the ground. So every year, one way or the other, we have
annual cicadas.”


JB: “Why 17?”


DB: “Jim, I can’t tell you, I don’t know, it’s just one of those great mysteries
of nature.”


JB: “That’s naturalist Dan Best, and I’m Jim Blum, for the Great Lakes Radio
Consortium.”

(cicadas fade out)

Related Links

Interview: Red-Winged Blackbirds Heralds of Spring

  • A male Red-winged Blackbird (Photo courtesy of the USFWS)

Many people in the Great Lakes region are told to watch for the robin as a sign that Spring has come. But that bird may not be the best indicator, even after this especially cold winter. The Great Lakes Radio Consortium’s Jim Blum decided to venture out beyond his backyard to find a better sign:

Transcript

Many people in the (Midwest/Great Lakes region) are told to watch for the Robin as a sign that
Spring has come. But that bird may not be the best indicator, even after this especially cold
winter. The Great Lakes Radio Consortium’s Jim Blum decided to venture out beyond his
backyard to find a better sign:


Blum: You might think of a robin or a bluebird as harbingers of spring but that may not be
correct. I’m Jim Blum with naturalist Dan Best, we’re at the edge of a marsh on a soggy
afternoon.


Best: Well Jim, it’s true that the greater numbers of bluebirds and robins arrive back in these
parts in March, but bluebirds and robins – they’re frequent enough in winter to ruin their
reputations as the heralds of spring.


Blum: Well, I’m thinking you have another bird in mind.


Best: Well, yeah, I was thinking of the blackbirds actually. The grackles and red-winged
blackbirds. They usually hit town in February.


Blum: I’ve always associated red-winged black birds with cattails. Aren’t they birds of the
wetlands?


Best: Well, yes. Marshes are their traditional habitat and remain their preferred habitat. They
weave a basket-like nest among the stems of the cattails, the rushes or other tall plants at the
waters edge. And while marshes are their favorite still, they’ve branched out.


Blum: You mean they’re starting to use other habitats?


Best: Why yes, as you know Jim, in a trend that unfortunately continues today marshes and other
shallow water wetlands – as they have been for decades – have been drained or filled for
agriculture and building.


Blum: Which would explain why so many of our rare and endangered plants and animals are
wetland species.


Best: Yes, indeed. However, as many forms of wetland wildlife have declined with the loss of
their habitat, red wing black birds, apparently more adaptable, have made a successful transition
into upland habitats, such as meadows and grassy interstate margins, hay fields, clover, alfalfa
fields.


Blum: Well there’s no wonder why there’s so many of them. I can recall those huge flocks that
we saw in the fall strung out across the sky almost like a plume of smoke.


(sound of huge flocks of birds)


Best: Yeah, and every night for several weeks they gather by the hundreds to roost in trees near
somebody’s house.


(red-wing blackbird song)


Blum: Well, red-wing blackbirds at almost any time of the year are pretty noisy birds. Their
song, if you can call it that, certainly doesn’t rival the cardinal or any other songbird for that
matter.


Best: No, you’re right about that, Jim. Can’t argue that point.


Blum: What does the bird look like? Can you describe it?


Best: Well, as the name implies they’re overall black. The males, they have a yellowish wing
bar and they also have a red shoulder patch or epaulet that they display while they are
establishing their territory or engaging in courtship.


Blum: What about the females?


Best: Well, they’re different looking. They actually look like big sparrows. That is, they’re
kind of a dark brown and very streaky.


Blum: Describe this display that the male is putting on.


Best: Well, they find a prominent perch and then from here they fan out their wings and tail
feathers and let out a real boisterous kon-kor-eeeee.


Blum: So this is to establish territory and they’ll keep doing this even before the females have
arrived?


(walking in grass)


Best: That’s right. They’re staking their claim but once the once the girls arrive well then this
display really kicks into high gear.


Blum: What’s the best way to see the antics of the red wing?


Best: Well, since these birds are pretty common, chances are you’re not going to have to go too
far from home. A little patch of cattails or reeds alongside the road. I mean, invariably they’ll be
perched on a wire or on a tree nearby will be a male red-wing displaying.


Blum: While other birds get more poetic respect, I have a sense you feel this bird is special.


Best: Well, yeah, as spring proceeds we’ll see more musical songsters come our way, but
doggone it, you know, when I hear that quirky song of the red-winged blackbird in late winter
when there is still snow on the ground, to me, that’s one of the first sure signs of spring.


Blum: That’s naturalist Dan Best. I’m Jim Blum for the Great Lakes Radio Consortium. Let’s
check out that cattail stand, do you think we’re going to get one?


Best: Oh, I’ll betcha there’ll be one there.


(sound of walking in marsh, fades out)

Earthworms Alter Forest Ecology

Most of us think of earthworms as beneficial creatures. Gardeners are always happy to spot a worm in the flowerbed because they add fertilizer to the soil. Many anglers say they’re the best thing for catching fish. But scientists are beginning to learn worms aren’t so friendly to Great Lakes forests. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:

Transcript

Most of us think of earthworms as beneficial creatures. Gardeners are always happy to spot a
worm in the flowerbed because they add fertilizer to the soil. And many anglers say they’re the
best thing for catching fish. But scientists are beginning to learn worms aren’t so friendly to
Great Lakes forests. The Great Lakes Radio Consortium’s Stephanie Hemphill reports.


(fade up Girl Scouts)


This Girl Scout troop is learning about worms. Judy Gibbs is a naturalist at the Hartley Nature
Center in Duluth. She shows the girls how to coax worms out of the soil. They pour water laced
with powdered mustard into the worms’ burrows.


It irritates the worms and they come squiggling up by the hundreds.


“Pour it in. Wait a minute. Here it comes. It doesn’t like the mustard and it comes right up.
Look at this one (laughter). oh, there’s another one. Look at it go!” (shrieks)


On their walk through the woods, the girls look for dead leaves. There aren’t many. Judy Gibbs
explains why.


“Here’s a leaf stem that’s being pulled into this hole. Who’s doing this? Ants! No. Worms.
There’s big night crawlers. You know what a night crawler is? They grow straight down into the
ground, and they come up at night and pull leaves down into their burrows. And they eat the leaf
right off. That’s why we’re not finding any leaves.”


Worms eating leaves might seem natural, but it turns out these worms aren’t native to these
woods. The last glacier buried most of what is now the Great Lakes region. When it melted,
plants and animals returned to create a community of maples, pines, songbirds, and tender plants
growing on the forest floor, like trillium…but not earthworms.


Cindy Hale is a biologist who studies the native wildflowers that grow in northern hardwood
forests. She loves the spring bloomers that take root in the spongy layer of decaying leaves on
the forest floor. Trillium, bloodroot, solomon’s seal.


Hale says many of these plants are disappearing.


“Sites that forty years ago were carpets of trillium have been slowly over the last two decades
declining to almost nothing, and people were scratching their heads, trying to figure out just
what’s going on.”


Earthworm populations are thickest close to cities. But Hale says people bring worms with them
when they come to the woods.


At first, settlers carried them in, along with the animals and plants they brought from Europe or
the east coast. These days, worms are spread by people who drive in the woods – loggers, ATV
riders…


“But in particular, fishing bait is a huge way that worms get moved around in our region.
Because there’s so many lakes and so much fishing.”


Hale and her colleagues set up test plots along an advancing line of worms in the Chippewa
National Forest in central Minnesota. The worms crawl about three yards further into the forest
each year. Hale is studying how the soil and the plants have changed as the worms advance.


Worms eat the decaying leaves on the forest floor. They mix that organic matter into the mineral
soil beneath it. And in time, they can use up all the organic matter and leave only mineral soil
behind.


That means the plants that have evolved to take root in the leaves on top of the soil have lost their
home.


Hale says these changes could affect every plant and animal that lives in the woods. She says,
for instance, even birds have declined by nearly 50% in the last fourteen years.


“Because ovenbirds nest in that forest floor, so if you lose the forest floor, then you may well
affect ground-nesting birds such as that. So when you start thinking about it, the potential
ramifications across the ecosystem get really wild.”


Hale says one of the big challenges in studying this problem is that there’s been very little basic
research – like how many worms are there are and where.


To gather more information and to get more people involved, Hale created a web-based learning
program. She’s asking teachers from around the country to have their classes do worm counts
and other research. Hale plans to add their data to the web page.


In Minnesota, the Department of Natural Resources is working with interest groups to try to slow
the spread of worms. Next year’s fishing regulations will include instructions not to dump your
worms at the end of a day of fishing.


For the Great Lakes Radio Consortium, I’m Stephanie Hemphill in Duluth.