|
The Swarm: Cicadas Emerge in Wisconsin
by Carijean Buhk, Urban Ecology Center

Outdoor concerts in Chicago have been
rescheduled, wedding planners are
searching for good sound systems, and
“foodies” are looking for recipes all for the
emergence of one little bug. Well, make
that millions of little bugs. Brood XIII of
periodical cicadas will emerge in Illinois
and parts of Wisconsin this June. And just
like the crowds at Summerfest, they’ll be
loud and looking for love.
Immature cicadas, called nymphs, live
underground for 13 or 17 years. Brood
XIII is on a 17-year cycle. Nymphs attach
to tree roots and suck the fluid to survive.
As soil temperatures warm, the nymphs
dig their way out and emerge en masse to
climb trees in order to complete the final
phase of their growing process. So many
emerge at a time that predators like reptiles,
birds, squirrels and even cats and dogs are
unable to provide the usual population
control found in other predator/prey
relationships. There are just too many
to eat. While hanging from branches for
roughly four to six days, nymphs shed
their exoskeleton, their wings inflate with
fluid, and their new skin hardens. After
that, the now fully-grown cicadas begin
their short, above-ground life cycles with
one goal – to find a mate.
It is the adult male mating calls that cause
outdoor concert promoters to change
their schedules. The calls from a group of
cicadas sound something like a blender
and can reach 90 to 100 decibels. This
is between a power lawnmower up
close (90 dB) and a chainsaw (100
dB). The males make this sound by
flexing their tymbals, drum-like organs
found on their abdomens. Females
respond by flicking their wings.
After reproducing, the males soon
die. The females live only long
enough to lay hundreds of eggs in slits
they create in tree branches. Six to eight
weeks later, weeks after their parents have
died, the eggs hatch, and the new nymphs
drop to the ground and begin to burrow,
starting the 17-year process over again.
Adult cicadas are black with red eyes, have
yellow or orange stripes underneath, and
are about an inch long with translucent
wings. They are not harmful to humans or
pets and do not sting or bite. Some people
consider them a rare delicacy and are
planning cicada-tasting parties. I’ve been
told they taste like shrimp.
To learn more about these insects, visit
Cicada Mania at http://www.cicadamania.com/cicadas/
Riverwest Currents online edition - June, 2007
|