Most of the wildflowers are past. All but a few butterflies and dragonflies have disappeared. But as the softening golden light of September draws us to wander through meadow tapestries and glowing woodlands, as long as the weather stays mild, we are bound to hear an endless music. It grows louder late in the day and lasts long into the night.

Sit and listen for a few minutes. It instills a profound calm.

The sound resembles the spring chorus of frogs and toads, but these are insects. Only a few insect groups use sound for communication: mainly Orthoptera, including crickets, grasshoppers and katydid. Loudest of all, cicadas, belong to a different order, Hemiptera, the true bugs. All make noise by rubbing body parts together.

In case you are stuck indoors, Music of Nature website provides some excellent sound tracks of nocturnal insect sounds and identifies many of the species.

Most familiar are the field crickets that tend to sneak into people’s houses and set up an annoyingly cheerful serenade of bright chirps in the middle of the night.

Katydids emit the loud, dry, unmusical zit-zit-zit often heard on hot summer nights. They look like smooth, leaf-green grasshoppers but keep to the treetops and are seldom seen.

The gentle, steady trilling audible wherever there is undergrowth this time of year is made by a group of insects called tree crickets. Apparently the snowy tree cricket (photo above), Oecanthus fultoni, is common around here, but I do not recall ever seeing one. They are well camouflaged.

The field guide, Bugs of Ontario (Lone Pine, 20013) by John Acorn and Ian Sheldon, recommends tracking the sound with a flashlight at night. The light will not disturb the insect, so you can watch it make music. The book also suggests tree crickets thrive in captivity. Be warned, the sound will seem much louder indoors at night.

If it seems primordial, well, this music has in fact been here practically since animals colonized land. Grasshoppers and crickets are among the oldest groups of winged insects. They arose from the great swamps of the Carboniferous period, 362 to 290 million years ago. So they have been singing a lot longer than we have.

Photo courtesy of Celeste Ramsay on Flickr via Creative Commons.