Crickets more pesky indoors than in garden

Perhaps no sound is more prominent in the landscape on late summer evenings than the chirping of tiny black, gold-tinged crickets. “What are those crickets doing out there?” one Ellsworth reader who recently moved to Maine asked in an e-mail. “Are they harmless or are they one of those insects that wreaks havoc, but we never actually see them in action?”

Hmm. Good question! For millennia, likenesses of the cricket have been cast in bronze, placed on the mantel and used as a symbol of good luck and fortune. But are they good fortune for your garden?

Here in Maine, we host a variety of cricket species in our gardens, lawns, fields and woods. The gardener is likely to find droves of them hiding out under rocks, logs or boards. House crickets (usually deep brown in color) and field crickets (usually black) are plentiful. In various temperate zones of North America, ground, snowy, camel and northern mole crickets are found. Crickets’ musical aptitude is universal among species, it appears.

Crickets get their name from the high-pitched sound or “chirp” produced when the male rubs his front wings together to attract a female. Male crickets “sing” by rubbing a sharp edge (called a scraper) at the base of one front wing along a file-like ridge on the bottom side of the other front wing. A series of chirps results. Chirps may vary from four to more than 200 per second. Males adjust and amplify the volume of the chirping by moving their wing surface.

Skilled insect specialists may identify different kinds of crickets simply by listening to their songs. The insects have special tunes for courtship, fighting and sounding warning alarms indicating danger to other crickets.

Do you remember as a child counting the number of times a cricket chirped in a minute and then performing some methodical calculations to figure out the sultry summer temperature? In fact, the frequency of chirping does tend to vary with the temperature: There are noticeably more chirps at higher temperatures. According to William F. Lyon, an entomologist at the University of Ohio, snowy crickets are said to chirp at a regular rate varying with the temperature. A good estimation of the temperature in degrees Fahrenheit is to add 40 to the number of chirps in 15 seconds, Lyon says.

OK, so that explains crickets’ vocal nature, but what, exactly, are these insects eating? Your lettuce? Your zinnias? Other insects?

According to Lyon, crickets may do more noticeable damage indoors if they infest the home rather than outdoors in the garden. They feed on a wide variety of fabrics, foods and paper products. When indoors, they gravitate toward cotton, linen, wool, rayon, nylon, silk and furs. They’ll also dine on sizing from wallpaper, glue from book bindings, fruit, vegetables, meat and even other crickets. Outdoors, the northern mole cricket is perhaps the most likely species to feed on garden crops, but their damage will likely go unseen. They tend to feed on roots, tubers and underground stems of grasses, strawberries and vegetables.

In short, these creatures probably don’t pose much of a threat to garden crops; they are more of a nuisance if you’re finding them in great abundance this season. While some crickets invade homes and become a pest merely by their presence, tolerance of these bitty animals is a better route to take rather than attempting to eradicate them from your yard.

Diana George Chapin is the NEWS garden columnist. Send horticulture questions to Gardening Questions, 512 North Ridge Road, Montville 04941 or e-mail dianagc@midcoast.com. Selected questions will be answered in future columns. Include name, address and telephone number.