As summer days slip away and goldenrod buds swell, birdsong is replaced by a six-legged symphony. The three tenors of the Driftless Area – cicadas, crickets, and katydids – take center stage, filling balmy air with an operetta of buzzes, clicks, and chirps heralding the approach of fall.
Cicadas are the loudest of the diminutive songsters. They resemble enormous flies with square heads and long, clear wings. Using special abdominal organs called tymbals, male cicadas buzz intensely from the treetops to attract females. An aggregation of toned and tuned males can crank out a collective buzz exceeding 100 decibels, comparable to a rock concert (move over Bruce Springsteen).
Similar to birds, each type of cicada has a signature buzz. The Driftless Region has nine cicada species. The dog-day cicada, also known as the heat bug, because it emerges mid-summer, is the most common. It sounds like a buzz saw. Periodical cicadas are bona fide celebrities, famous for synchronized mass emergences and a deafening din, the culmination of 17 years underground as nymphs feeding on tree root sap. Their first breath of fresh air after more than a decade of dining in dirt may help explain their acoustic exuberance. Cicadas live brief but spectacular lives, with most surviving for only four to six weeks. By late summer, the cicada chorus falls silent.
Katydids resemble a cricket-grasshopper mash-up. They are distinguished from both by antennae longer than their bodies. The 20 species of Driftless katydids are avowed vegetarians, opportunistically munching leaves, stems, and flowers. Their size (one to four inches long) and soft bodies make them a favorite prey for birds. Their leafy green color helps to conceal them, as do nocturnal performances.
Male katydids tune up as the moon rises, rubbing their wings together – a behavior called stridulation – to create their eponymous sound: “katydid, katy didn’t, katydid, katy didn’t.” Despite their apparent indecision, the song is an effective attractant for female katydids keen on finding a mate. Late summer is peak Katydid season, although a few intrepid individuals manage to endure until fall.
Crickets are the last, but not least, of the miniscule musicians. They’re the toughest of the lot, chirping well into fall, long after the seasonal curtain drops on cicadas and most katydids.
More than 900 species of crickets live worldwide, with 100 species found in the United States. In the Driftless, the most common is the field cricket, a sturdy little bug with a rather pedestrian exterior. Contrary to the dapper image portrayed by Disney’s Jiminy Cricket, complete with a blue top hat and umbrella, the field cricket is clad in monochromatic black. The lack of “spiffy” helps conceal these ground dwellers from a host of would-be predators. Unlike cicadas and katydids, most crickets are omnivores, noshing all manner of vegetation and even the occasional aphid or small spider.
Like katydids, the field cricket’s signature chirp is the product of stridulation by males looking for love. They begin their solo performances in July and continue into October, until ultimately thwarted by frost. Because crickets are ectothermic (cold-blooded), every aspect of their lives, including chirping, is regulated by temperature. As it gets colder in the fall, the crickets’ chirping becomes slower and slower. Amos Dolbear, a 19th century American physicist and very bright guy, realized the Fahrenheit temperature can be estimated by counting the number of cricket chirps within 15 seconds and adding 40. Clever.
This fall, long after the cicadas and katydids have signed off the airwaves, step into the cool autumn air to enjoy the crickets’ waning serenade. And don’t forget to estimate the temperature.
Mary & Craig Thompson
Mary and Craig Thompson live in wooded bluffs north of La Crosse. They now rely on crickets to tell them when to don their hoodies.
