Monday, August 20, 2012

Summer Soundtrack

Maybe your summer soundtrack is “Call Me Maybe” by Carly Rae Jepsen or maybe you’re hearing waves rolling in on a beach.  I’ve got an earful of cicadas!  Cicadas are the pulsating and buzzy sounding insects you hear from trees and bushes in mid to late summer.  Only the males call, they vibrate a special organ on their abdomen called a tymbal.  The Eastern Shore of Maryland actually has about half a dozen species of annual cicada which should not be confused with the periodical cicada which emerges every 17 years in huge numbers (like in 2004). 

Swamp Cicada from Baltimore County.  Photo by Jim Brighton 
Annual cicadas have a pretty cool life cycle:  females lay eggs in soft twigs and other plant material.  Tiny nymphs hatch out the same summer and drop to the ground where they burrow into the soil.  Over the next few years (the exact length of time depends on the species) the nymphs feed on roots and grow bigger and bigger.  Finally, one summer when they are about an inch or so long, they dig their way out of the ground, climb up to a safe perch and hatch out of their brown skin.  They sit a while to allow their wings to unfold and strengthen then they fly away leaving their crunchy shell behind.   The adults only live a few weeks before reproducing and dying.

The crunchy brown shell that remains on a tree trunk after a cicada has emerged.
In addition to being super cute in a bug sort of way, I also like cicadas since they pose no threat to humans, they do not bite or sting.  Under normal circumstances they do not damage crops or plant material.  Humans in many parts of the world actually eat cicadas as a good protein source.

Cicadas, by the way, are NOT locusts.  Locusts are grasshoppers, in the scientific order Orthoptera.  Cicadas are more closely related to aphids and are in the order Homoptera.   You may recall from high school biology the classification runs kingdom, phylum, class, order, family, genus, species so organisms in different orders are really really unrelated!

Cicada from CRFRS grasslands.

There are loads of other critters adding music to your summer days and nights.  Crickets and katydids are other insects that make noise and don't forget about the various frogs and toads.  Why not take a few minutes on a summer evening this week to stop and listen to all the creatures singing!

Maren Gimpel is a field ecologist at the Chester River Field Research Station.  Photos and stories about the goings on of CRFRS can be found at or at

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