During these long last days of summer, after school starts and the evenings cool down a little, the bugs begin their final push to mate and prepare for the long cold seasons ahead. They are easy to observe flying and jumping and preening and making noise – lots of noise!
The last warm nights of summer are as exciting as the days. You don’t even need to get out of the city to hear the choruses of crickets and katydids, but if you can get away from the traffic and noise, the sounds are awesome and even deafening sometimes. Trying to distinguish just one single triller or chirper in the ensemble is impossible. So many sounds mash together in such an undecipherable cacophony it is hard to believe the insects themselves can tell the difference. But they can. These calls are essential for them to find each other to reproduce while there is still time. Before winter.
An easy voice to pick out in the noisy nocturnal crowd is the very loud choppy Dee-dee-dee of the Common True Katydid (Pterophylla camellifolia). As with many species of chirping insects, the males are the primary callers. They make this incredible noise competing for females. In some Katydid species the females respond, often with a less obvious call. Sound communication is especially effective at night, when visual displays don’t work and many nocturnal predators hunt by smell or feel. But making such a loud noise is still a risky move. Being the loudest bug on the block might attract mates, but it can also attract predators! Females don’t usually take risks like this in courtship – they are too valuable as egg layers.
The raspy, staccato mating call of the Katydid is very difficult for predators (or people) to hone in on. Typically, short sharp vocalizations like this are used as warning signals between cooperating animals since they are easy to hear within a certain range but hard to locate. For instance, in bird warning calls a short, sharp alert chirp from a friend doesn’t need to be located precisely. A general alarm in the vicinity is enough to know to fly away!
But this feature can be a problem in a mating call. A female has to know where to find the caller! So the female Katydids’ listening abilities are specifically tuned to males of their species. Their ‘ears,’ or tympanic membranes, have directional features and specialized receptors that can locate the guys with ease – when they want to!
For us humans, these common insects are challenging to find! If you want to try to see a Katydid some late summer evening, get a bright light and even some friends to help you triangulate. Find a safe place where you can hear Katydids calling. Their call is as cryptic as their green, leaf-shaped body. Our general hearing isn’t able to locate the precise direction well enough for our poor night vision.
But to the benefit of Nature’s night music, the reckless, eager-to-mate males make for quite an auditory experience! See if you can find a nice patch of Shagbark Hickory trees. Shagbark is a Katydid favorite. Check out some of the beautiful spaces in the Columbus Metro Parks. Many are open until 10 p.m., nightly through September and into October. Katydids start singing a little bit after dark and will continue to sing until around midnight every night until mid October or the first hard frost in Ohio.