by Douglas Tallamy (2021, Timber Press Inc., Portland, OR)
Katydids (pp. 106-107)
Once upon a time, there was a young woman named Katy who fell in love with a handsome young man. Alas, he did not share her feelings, and he married another. Soon thereafter, he and his young bride were found poisoned in their bed. Who perpetrated the crime? That was never determined, but some say the insects in the trees were watching that night, and each summer they solve the mystery by singing “Katy did, Katy did!” Or so the legend goes.
From age four through my early 20s, I was lucky enough to spend a good part of every summer camping in North Jersey with my family. A milestone of each summer, marking the midpoint of our camping adventures, was when various species of katydids—large, grasshopper-like insects—began their nightly chorus in mid-July. Not only did the katydids tell us that summer was half over, but they also signaled the approximate time each night. The katydids in the oaks above our tents were loudest before midnight but became less and less vociferous thereafter, falling completely silent from about 4 a.m. on. The overlapping “katy-did, katy-did” songs of many hundreds of these large orthopterans was a loud yet soothing white noise for me, something I looked forward to each summer, perhaps because its dependability helped ground me during a time of rapid transition in my life.
Katydids belong to the family Tettigoniidae, the long-horned grasshopper, a common name that refers to their extraordinarily long and delicate antennae. There are 262 species of tettigoniids in North America, but only four species of true katydids, the tettigoniids that spend their entire life in the canopy of oaks and other deciduous trees. It is the males in these species who are the singers, and they generate their songs through stridulation, a process in which one body part rubs against another. In the case of katydids, there is a scraper on the anterior end of one hindwing and a file at the same location on the other hindwing. By slightly lifting these wings and moving them rapidly back and forth, the scraper moves across the file, producing a surprisingly loud, species-specific song.