Hear cicadas - the songs of summer

The buzz of cicadas are songs of summer in Iowa.

Iowa State University extension reported that some periodical, or 17-year, cicadas are emerging early this year. Those differ from the annual cicadas we hear every summer.

 I asked Donald Lewis, entomologist for ISU extension, about the difference between the two and how Iowans can be part of a national cicada reporting effort.

 Here is what he wrote:

   The periodical cicadas will be here through the end of the month.  For practical purpose, June 30 would be the deadline for reporting, though most will be much earlier than that.

 After June 30, people are likely to start hearing annual cicadas in the middle of the day.  Reports of "I heard one!" at that time will not be accepted at face value as periodical cicadas, since it is more likely to be annual cicadas.

 Aside from time of year, the annual and periodical cicadas sing at different times of the day.

 Annual Cicadas (also known as dogday cicadas) sing in late afternoon to dusk, from July to frost.  You usually hear one, or a few at a time.

 Periodical Cicadas (also known as 17-year cicadas) sing from 10:00 to 2:00 in May and June.  During mass emergence years, you hear thousands to tens-of-thousands at a time.

 The songs are different but not in a way that is easy to describe.  Part of the difference is just the sheer volume.  Here are links to songs if you are interested. 

 Annual Cicada   http://www.musicofnature.com/songsofinsects/iframes/cicadas/popup_tibiprui.html

 Periodical Cicada  http://www.musicofnature.com/songsofinsects/iframes/cicadas/popup_magisept1.html

 And here is more from ISU extension on the early emergence of the 17-year cicadas:

 Just when you think your life has become predictable and routine, Nature gives you something new and exciting. Life is grand.

As many know, the periodical cicada (also known as 17-year cicadas, and nicknamed “locusts”) emerge in well-timed intervals of 17 or 13 years. In Iowa we have just a few "broods" that we are fortunate to see, but only in central, eastern and south-eastern Iowa. The last emergence of periodical cicadas happened in far eastern Iowa in 2007 (Brood XIII) and before that, the last major brood covering from central Iowa to the southeast corner was in 1997 (Brood III)

Brood III is not “scheduled” to reappear until 2014, and nationwide records indicate there should be no periodical cicada emergence this year in the country.

But wait. Here they are! The unmistakable inch-long, black insects with bright red eyes, the tens-of-thousands of empty shells on the ground and tree trunks, and the unrelenting buzz of noisy males singing from mid-morning to mid-afternoon.

It turns out that there have always been cicadas who could not count, and a few would emerge early or late. However, accelerated emergence has become a common occurrence in the eastern USA over the past several years and large numbers of periodical cicadas "mis-count" and emerge early. And they come out 4 years early. Always 4 years. In that regard the periodical cicadas reported this week in Madison, Warren and Monroe counties are "on time" for a premature emergence of Brood III.

See the HHPN article from May 9, 1997 for basic background about periodical cicadas.

If you are interested in more about early emergence, here is a news article from Science Daily about early emergence in eastern USA in 2009.

Finally, we would like to document the early emergence in Iowa and add our experiences to the national database. If you hear periodical cicadas in the next month or if anyone asks you about “thousands of cicadas per tree” in wooded areas, unrelenting buzzing from cicadas in mid-morning to mid-afternoon, or thousands of empty “locust shells” on the ground in late May to June, please send us a message at

insects@iastate.edu.  Thanks.