Crickets

(This 706th Buffalo Sunday News column was first published on October 10, 2004.)

As the weather cools and fall advances, all our senses are called into play. On any trip into the countryside our vision is excited by the rich colors of maple leaves and goldenrod and aster blossoms. Our noses twitch with the smells of cider and cabbages. We feel the smooth moist skins of apples and pears and enjoy their wonderful taste.

Meanwhile, those sounds of spring and summer - the croaks and trills of frogs, the jug-o-rum of toads, the happy songs of birds and the high decibel whines of grasshoppers and cicadas - are replaced by the lesser but still distinctive sounds of crickets.

I'm sure that the metronome-like chirping of the cricket annoys some people, but to me it is very different from, for example, the calls of whip-poor-wills or chuck-will's-widows. I'm always excited when I first hear the cry of one of those uncommon goatsuckers, but my excitement very quickly turns to irritation with their continuing loud and sleep-preventing repetitions. The cricket on the other hand I find more like a ticking clock - somehow reassuring in its companionship.

In this I am far from alone. Nathaniel Hawthorne had it right when he said of the tree cricket, "If moonlight could be heard, it would sound like that." And for at least a thousand years the Chinese have so appreciated cricket songs that they have kept them in cages in their homes in order to listen to them.

An eighth century account tells us about this: "Whenever the autumnal season arrives, the ladies of the palace catch crickets in small golden cages. These with the cricket enclosed in them they place near their pillows, and during the night harken to the voices of the insects. This custom was imitated by all people."

Of course the common people didn't have gold and instead made their cages of bamboo. Some of the cages were even designed to hang from a belt or necklace so their owner could carry them at all times.

Those cricket chirps are accomplished by stridulation, that is, rubbing together two of their hard body parts. Like many other insects, crickets have two pairs of wings. On each cricket's forewing is a thickened vein with 50 to 350 microscopic ridges, much like a tiny file. To "sing", the cricket rubs this file against the hardened edge of an opposite wing. This causes both wings to flutter or resonate and produce sound. The process is like scraping an electrician's file across the edge of a tin can.

So the cricket doesn't use its mouth to speak. Fair enough, because the female doesn't use normal ears to hear; instead she hears through her shins. She recognizes sounds through spots called tympanum located on the lower parts of her forelegs.

There are many species of cricket. It turns out that what most of us know as the field cricket can be any of a half dozen species that may only be identified in the field by minor differences in their calls. These crickets are black or brown and grow to be between a half-inch and an inch in length. Although the house cricket belongs to a different genus, it too is easily confused with field crickets, which also occasionally venture into homes.

All of these crickets share a similar life history. In spring the females lay their eggs in cavities. The eggs hatch in summer and the resulting larvae molt between eight and twelve times finally to become adults. In all stages outdoor crickets consume leaves and dead insects while indoor crickets feed on clothing and carpets. Fortunately any damage they do is relatively minor.

Just over a hundred years ago a Tufts College physicist named A. E. Dolbear noticed that one cricket species, the snowy tree cricket, chirps at a rate that increases with temperature. He even came up with a formula: T = 50 + (N-40)/4, with N the number of chirps in a minute and T the temperature in Fahrenheit. Any 9th grade algebra student should be able to simplify Dolbear's equation to give T = 40 + N/4, which tells us that we can determine the temperature by counting the number of chirps in 15 seconds and adding 40.

Now all we have to do is find a snowy tree cricket. Fortunately it is a fairly common species here. Gary Dunn describes it as "whitish or pale green with the top of the head yellowish. The wings are broad (widest toward the tip) and lay flat over the back. They favor deciduous woodlands but are commonly encountered in raspberry and blackberry thickets." Once we've found it we can take out our stopwatch and start counting.

Most of us would, however, find it simpler to refer to a thermometer.-- Gerry Rising