This species owes its Latin name to Dr. B. B. Fulton, a leading Oecanthus expert. This is the most common species in North America, better known for its song than its appearance, however.
As among other singing insects, the males emit sounds to attract partners. They produce a pleasant “song” by rapidly rubbing their wings together. The sound is similar to that of spring peepers.
These insects prefer to stridulate from shrubs on forest edges or in open wooden habitats. When a singer is successful, a female approaches him and puts an end to the concert by initiating mating.
Groups of males from the same species are often heard on hot late-summer evenings. Each stridulation consists of eight (sometimes five) pulses at a frequency of 3 kHz, and when the air temperature is 21 degrees Celsius, listeners can count over 120 stridulations per minute. The sound varies with the temperature, becoming higher pitched as the mercury rises.
Their other common name of thermometer cricket is very apt. In 1898, Amos Dolbear, author of “The cricket as a thermometer,” systematically studied the sounds made by different cricket species and correlated them with the air temperature in degrees Fahrenheit. He established the formula T = 50 + [ (N-40)/4 ], which became known as Dolbear’s law.
The formula can be used to estimate the temperature in degrees Celsius by counting the number of stridulations produced in 8 seconds and adding 5. Example: 15 stridulations + 5 = 20ºC.