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Crickets, katydids fill summers days with courting calls

“There are frogs in my trees at night and they’re driving me crazy!” one caller said.

Another person who enjoys the sound told me, “We like to take a walk at dusk to hear the frogs singing in the treetops.”

Yet another person asked, “Why are the frogs so loud this time of year?”

With a smile I try to explain that the pulsating soundscape of late summer is brought to us courtesy of katydids and their insect cousins, not frogs. The typical response is, “I’m sure these are frogs. I’ve seen frogs on my porch.”

Yes, frogs have been out and about this month and it’s very likely that you’ve seen them, but they are silent this time of year. Amphibians’ sonorous serenades ended when their breeding season concluded in early summer.

The nocturnal noisemakers this month are insects belonging to a group known as the orthoptera. Their carousing can be heard over the din of air conditioners on hot summer nights. They have fabulous names like the Virtuoso Katydid, Elegant Bush Katydid, Mischievous Bird Grasshopper, Confused Ground Cricket, Slightly Musical Conehead and more.

These orthopterans tirelessly trill, buzz, saw and squawk night after night from early August until the first hard frost in October.

True katydids are the insects most confused with frogs this time of year. It’s tough to actually see them, unless you climb a tree and literally go out on a limb with a flashlight. But you may get lucky and find a big green True Katydid on a low bush or clinging to your porch screen.

The mysteries of orthopteran song have intrigued humans for many centuries. Asian cultures, in particular, have refined appreciation of insect music.

“In ancient times,” wrote Lang Elliott and Wil Hershberger in “The Songs of Insects,” “city dwellers (in China and Japan) would take autumn vacations to remote areas of the countryside in order to appreciate particular insect songs or choruses known for their inherent beauty.”

The hows and whys of this beautiful music were unveiled in the 20th century. Technological advances allowed scientists to research insect anatomy, physiology, and behavior, and most importantly, to record insect sound.

Harvard physics professor George W. Pierce analyzed sound transmission in underwater communications and anti-submarine defense during World War I. In retirement, Pierce turned his attention to more fun sound wave challenges: insect calls.

With instruments primitive by today’s standards, Pierce cracked the codes of orthopterans. His graduate assistant, Vincent Dethier, popularized his work in “Crickets and Katydids, Concerts and Solos,” a delightful book that opens up the world of orthopteran music to the layman and scientist alike.

The mechanics of orthopteran sounds are straightforward. Much like using a wooden spoon on an old-fashioned washboard to make music, orthopterans rub two body parts together in a process known as stridulation. In the case of grasshoppers, the hind legs are rubbed against the forewings to make sound.

Crickets and katydids opt for the wing-to-wing method. They elevate their wings in the process and enhance the song by vibrating the wing membranes. Katydids are left-handed musicians, always using a file on the left wing against a scraper on the right. Snowy Tree Crickets utilize posture to amplify their sound. They may position themselves in front of a leaf — or sometimes inside a rolled-up leaf — so that the leaf will act as a megaphone.

The motivation to make music is familiar: courtship and mating. Males take the lead in this arena and thus music-making among orthopterans is an exclusively male endeavor. Females, of course, must be able to hear the music. And not only must they hear, but they also must be able to discriminate among different calls.

Females are able to receive the males’ messages by virtue of strategically placed hearing organs called tympana. In the case of crickets and katydids, these “ears” are on the base of the front legs; for grasshoppers, the first abdominal segment.

What makes the top 10 in the orthopteran hit parade? Elliott and Hershberger explained that it’s not the pitch of the music that pleases the ladies; it’s all in the timing and intensity of the calls. The females are attuned to subtle differences in the intervals and decibels of the calls. Discriminating gals select their guys accordingly.

Where does this Insectpalooza happen? Just about everywhere. Dethier points out that there’s an orthopteran for every habitat — woodlands, wetlands and prairies alike. Coneheads buzz from herbaceous vegetation in open areas. Ground crickets and grasshoppers call from gardens, farm fields, roadsides and prairies.

True katydids take lead vocals in the oaks and the hickories and the maples and the basswoods. Their raspy, ratcheting racket from the treetops is the sound most often confused for a frog. It’s downright deafening on a warm August night. You’ll hear them in the woods arguing incessantly, “Katy did!” “No she didn’t!” “Yes she DID!” “No she DIDN’T!” Evidently this is a very alluring argument, as the males have been utilizing this debate forum to attract females for millennia.

By contrast, Snowy Tree Crickets make lovely chirping calls that create a soothing night time chorus in the summer woods. Their name comes from their white-ish appearance, not from the season of their calling. In fact, when the snow flies Snowy Tree Crickets will be long gone. These dainty insects may have nothing to do with snow, but they do have a meteorological connection. Their calls provide an accurate temperature reading. Count the number of chirps in 13 seconds, add that number to 40 and voila! You’ve got the temperature in degrees Fahrenheit.

Frogs had their day (or night) in the limelight last spring. The insects now take center stage. Thus, just as amphibians provided a cacophonous chorus to welcome spring, insects are now producing the grand finale in the sumptuous soundscape of late summer.

Ÿ Valerie Blaine is a naturalist with the Forest Preserve District of Kane County. She welcomes your comments and questions. You may reach her at blainevalerie@kaneforest.com.

The sounds of a summer night are caused by katydids, shown here, and other members of the orthopteran family of insects — not frogs, as many people assume. Bob Chwedyk/Daily Herald 2007

Learn more about katydids

Curious about the nightly noisemakers? Join naturalist Valerie Blaine for “Cicada Songs and Katydid Calls,” an exploration of insect wildlife of dusk and dark.

This family program will be held from 7:30 to 9 p.m. Wednesday, Aug. 24 at <a href="http://forestpreserve.countyofkane.org/Images1/Aerial%20Views/leroyOakes.pdf">LeRoy Oakes Forest Preserve in St. Charles.

Armed with flashlights and sampling jars, participants will search the fields and forest for the insect songsters and see them making their strange sounds.

Registration is required. Call (847) 741-8350 or email programs@kaneforest.com.</a>