Take Me Outside: Sweet sounds of late summer

  • A lubber grasshopper sits on a sunflower plant. AP

  • Grasshoppers use this time of year to perform their late summer swansong. AP

For the Monitor
Monday, September 03, 2018

Birds are beginning to migrate. Some leaves are starting to fade and gain fall colors. Children and teachers are heading back to school. Many signs tell us that the seasons are changing. Some of those clues are the prominent sounds of crickets and grasshoppers as they perform their late summer swansong.

Spring is usually thought of as the time for courtship and reproduction, but for crickets and grasshoppers, now is when mating and egg-laying occurs. That is why we hear their calls, mostly created by the males, as they attempt to attract females and intimidate competitors.

The sounds, like bird songs, are specific to each species. When a male calls, the female of his kind will respond and approach him. After mating occurs, she deposits her fertilized eggs in the ground, or sometimes in plant material, where they will remain for the winter. In the spring (or summer, depending on the species). the eggs will hatch and begin to grow.

Cricket nymphs (juveniles) go through eight to 12 molts over a period of up to 90 days until they are mature. But that’s all for another time.

What is going on right now is a regular songfest. The crickets and grasshoppers, including some of the long-horned grasshoppers that we call katydids, make their music using their wings. One of the wings has a series of ridges, like a file, and it is rubbed against the other wing which has a scraper.

The chirps, buzzes and trills are created by the variations of this rubbing and the vibrations that result. It is similar to what happens when you run your finger across a comb.

Learning to distinguish the different sounds can be quite interesting. If you hear a musical whistle with a distinctive pitch (one that you could perhaps imitate with a hum or whistle), it is being made by a cricket. Grasshoppers make a more mechanical sound, like that of sandpaper being rubbed together. The katydid calls at night with a nasally sound that seems to be saying, ‘’katy-did, katy-didn’t.’’ What species make up the chorus depends on whether the concert is during the day or at night. During the daytime, you may hear another type of insect, the cicada, which contract abdominal “tymbal’’ muscles to make their sounds. They create a high pitched, long, whining sound, one of the loudest of any insect.

Within the cricket group, there are further distinctions. Snowy tree crickets are rather lacy and pale green.

As their name implies, they are found mostly in trees and shrubs and are hard to see because they blend in with the leaves. They sing primarily at night and have a very regular, high pitched and evenly spaced chirp that resembles the beeping of a bus backing up.

They are sometimes called the “thermometer crickets’’ because the rate of their chirping is temperature dependent.

As the temperature rises, their chirping increases.

If you count the number of chirps you hear in 15 seconds and add 40 it will give you the approximate temperature in degrees Fahrenheit.

This trick only works between the temperatures of 45 to 90 degrees, but it is fun to experiment and see how accurate your local crickets are (or how accurate your thermometer is!). The slowing cadence of these calls relative to the declining temperatures will be another sign of autumn.

The crickets that we most commonly see are the ground or field crickets, which are dark brown or black. They too make rhythmic chirps, but also create the high pitched, pulsating trills.

Their sounds can be heard either during the day or at night.

If you find one, make note of its location. The males can be quite territorial and will often stay in the one place for days. If you visit a spot repeatedly, you are likely to encounter the same individual. But don’t be surprised if one day he is gone.

This is a season of transition during which things are constantly changing. That’s one reason it is great to stop and take notice of all that’s going on, because if you don’t, you may miss it – at least until next year.