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The
17-Year Cicadas
This
natural event occurred in the Summer of 2004
Enjoy
nature’s display of these harmless, fascinating
insects
Cicada
Songs In Reston
If
you listen closely, you can hear the different songs
of all three species.
Background
Information
One
of the most amazing natural history phenomenons to
take place in North America will occur this spring
right here in Reston, as it will in more than ten other
states in the Northeast, Southeast and Midwest. Three
species of black and orange Periodical Cicadas have
spent the last 16 years under ground feeding on tree
roots –
they are now ready to emerge to sing, mate and lay eggs.
(Another species - black and green, called the “Dog
Day” cicada -emerges each summer in much smaller
numbers). The event is an amazing display of life as
close to 1 million Periodical Cicadas per acre will
emerge from mid-May to mid-June. By late June the adult
cicadas will have died, leaving it up to their young
to hatch from eggs laid in trees and then burrow 2’ beneath
the ground for another 17 years.
There
are many different broods of 17-year cicadas spread
out around the eastern half of the U.S. This means that
almost every year there are 17-year cicadas emerging
somewhere. The brood that lives in this area is Brood
Ten – the last time they emerged was
1987. It’s the largest of all the broods and this
is their year – check out this map, http://insects.ummz.lsa.umich.edu/fauna/michigan_cicadas/Periodical/BroodX.html.
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Cicada
Photos
http://alpha.fdu.edu/~boyer/Entomology_folder.html/Cicada_gallery.html
http://entomology.unl.edu/images/pcicada/pcicada.htm
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Cicada
Songs
Three
species of 17-year cicadas will emerge this spring,
Magicicada septendecim, Magicicada cassini
and Magicicada septendecula. Each species has
a distinctly different song. In addition, each species
has 5 basic sounds: chorus, 3 stages of courtship calls
and female wing flicks.
To
identify which species you have in your neighborhood
check out the following: (provided by The
University of Michigan Museum of Zoology)
Female wing flick signal: Females
produce timed "wing flick" signals in response
to male calls. The timing of this signal in relation
to the male call is species-specific.
1.
Magicicada
septendecim 51K
2. Magicicada
cassini 97K
3. Magicicada
septendecula 41K
Magicicada
septendecim songs:
1.
Chorus
2. Calling
Song / Court I (complete phrases)
3. Court
II (fragment)
4. Court
III (fragment)
Magicicada
cassini songs:
1.
Chorus
(septendecim in background)
2. Calling
song / Court I (complete phrases)
3. Court
II (fragment)
4. Court
III (fragment)
Magicicada
septendecula songs:
1.
Chorus
(mixed with cassini)
2. Calling
song (complete song)
3. Variant
of calling song? (complete song)
4. Court
III (fragment)
Let
Us Know Who’s Singing In Your Backyard!
Have you been able to identify which species you have
in your neighborhood? Reston Association has no records
indicating which of the three species occur here.
Please help us out by listening to their songs and
letting us know which Magicicada sp.
lives near you. If you live in Reston, please
send your observations, photos or sound recordings
to
(**This natural event occurred
in the Summer of 2004**).
If
you don’t live in Reston but would like your
observations recorded, please check out this website,
http://www.msj.edu/cicada/report.html.
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FAQ
- Frequently Asked Questions: |
Q:
Can cicadas hurt you?
A:
No. Despite their impressive numbers they
are completely harmless, unable to sting or bite. Cicadas
are not poisonous to people or animals and do not carry
any diseases. However, they are clumsy flyers and
may startle you by running into you or even landing
on you and emitting a loud buzzing sound. If this happens
simply brush them off. You can also take this opportunity
to take a closer look at these interesting creatures.
If it’s a male you can look at their singing organ
by gently raising their wing and looking for the tymbal
located where the wing meets the body. If it’s
a female they will have a pointed abdomen will a sheathed
ovipositor, the organ they use to lay eggs.
Q:
Will cicadas hurt the trees?
A:
Very little. Adult cicadas do not eat leaves
like caterpillars or locusts – they suck juice
from the plant’s stem like aphids. Almost all
feeding during a cicada’s life is done on tree
roots while it’s underground as a nymph. Adults
do little to no feeding once they emerge – they
are too busy singing and laying eggs and cause no damage
to the tree by feeding on it.
The
female’s egg-laying procedure is the only stage
of the cicada’s life cycle that causes damage
to the tree – and even this is minimal. Female
cicadas use their ovipositor to make a small slit on
the tips of tree branches 1” in diameter or less.
Several hundred eggs are deposited in several slits.
After a few weeks the leaves on the tip of the branch
die and turn brown. Eventually the tips of these branches
will break off, serving as a sort of natural pruning.
Large trees have no problem recovering from this and
suffer no long-term damage. For smaller trees with
many egg-laying sites the result could be described
as over-pruning. If you have ornamental fruit or flowering
trees in your yard you may want to consider netting
them. Please see our Landscape Management section below
for tips on how to do this.
Q:
Should I let my pets eat cicadas?
A:
Sure – just not too many.
Cicadas are not poisonous to eat and can be safely ingested
by your pets (or people!). However, some pets (dogs
especially) go a little nuts and gorge themselves, eating
way too many and making themselves sick. When this happens
they simply vomit them up and out, no harm done - just
as they would from eating too much grass.
Q:
Should I use pesticides to protect my property from
cicadas?
A:
We suggest that you use alternatives. Please
try to refrain from using pesticides – it won’t
stop the cicadas and will only harm other wildlife and
pollute Reston’s watershed. Cicadas cause little
to no damage to the landscape. For alternatives to
pesticides please see our Landscape management
section below.
Q:
Are cicadas locusts?
A:
No. Although they’re often called locusts,
they are not. Locusts are large grasshoppers that live
in arid regions of the world, while cicadas are more
closely related to aphids. Locusts do a great deal
of feeding as adults and can devastate whole crops
in a matter of hours - cicadas however feed mostly
underground as nymphs on tree roots and cause very
little damage, either then or as adults.
Q:
What are the benefits of such large numbers of insects
emerging all at once?
A:
Several – for both cicadas and the environment.
For cicadas the advantage is simple – safety in
numbers. There’s far too many for predators to
eat them all, insuring that most will be able to mate
and lay eggs.
For
the environment, it’s a healthy dose of nutrients
at a perfect time to feed hungry animal mouths and
growing tree roots. Many species of mammals, birds,
fish, reptiles, amphibians and other insects will
spend the spring and summer feasting on cicadas and
feeding them to their young. Kestrels and Screech
Owls, Bull Frogs and Bass, Foxes and Flying Squirrels
are just a few of the critters that will benefit
from the cicada emergence. For plants, the benefits
begin in mid to late summer when cicadas begin to
die. All those cicada bodies act as fertilizer for
the forest floor, sending nutrients to thousands
of plant roots.
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Dead
Tree Branches - What's causing it?
Cicada
aftermath – what’s up with all those dead
tree branches???
Q:
Why do so many trees (especially large oaks) have brown
leaves and snapped twigs on the tips of their branches?
A:
From female cicadas laying their eggs. Female
cicadas use their ovipositor to make a small slit on
the tips of tree branches 1” in diameter or less.
Several hundred eggs are deposited in several slits.
After a few weeks the leaves on the tip of the branch
die and turn brown. Eventually the tips of these branches
will break off, serving as a sort of natural pruning.
Q:
Does this hurt the trees?
A:
Very little. Large trees have no problem recovering
from this and suffer no long-term damage – in
fact, it actually encourages new growth. For smaller
trees (approx. 4’-8’) the result could be
described as over-pruning, and may cause stress severe
enough to cause serious damage. Small trees in a woodland
setting will be fine as the female cicadas are spread
out among many trees. Isolated trees in yards and landscaped
areas suffer more damage as the female cicadas have
fewer trees to choose from. The important thing to remember
here is that cicadas have been in North America for
millions of years. If they caused severe damage then
Reston would not be full of large, healthy trees… which
it is.
Q:
Should I do anything to help the trees in my yard recover
from the cicada damage?
A:
Your Large trees will be fine and don’t need
any help. For small trees (4’ to 8’)
just give them a little TLC: extra water, some new mulch
and a small dose of a mild, slow-release fertilizer
such as Osmocote. Give them a full year to recover –
by next summer you’ll know whether they are going
to survive.
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