Male tree crickets sing to attract females. Some song pulse rates are over 100 pulses per second. that means, the row of teeth on one wing are moving across the scraper on the other wing 100 times per second!
Each species has a unique sound that is recognized by female tree crickets. They all raise their wings while singing….and their sound travels for long distances. It is difficult for the human ear to detect the differences in frequencies. The song patterns are easier to tell apart. Some have a continuous trill, some trill in short bursts, and one makes musical chirps.
This image is a blue waveform of a continuous trilling pattern. This waveform captured 15 seconds of singing by this male Forbes’ tree cricket when the air temperature was 72.2 F. We can use this waveform to count how many pulses occurred per second. Most of the species in the continental US have this pattern.
Here is a sample recording of a Pine tree cricket:
The image below shows the intermittent bursts of trilling pattern of a Narrow-winged tree cricket. Other species with this pattern are Davis’ and Thin-lined tree cricket.
Here is a sample recording of a Narrow-winged tree cricket:
Two-spotted tree crickets sound somewhat similar to Narrow-winged tree crickets, but their pattern is more irregular and they sound more frantic. In cooler temperatures, however, their song is more mellow – very much like a Narrow-winged tree cricket.
Here is a sound sample for Two-spotted tree cricket:
The following image shows the chirping pattern of a Snowy tree cricket. Another species with this pattern is Riley’s tree cricket.
Here is a sample recording of a Snowy tree cricket:
Using digital software (Raven has a free version), you can count the number of song pulses per second. Here is an example using 1 second of the song from Oecanthus forbesi.
This graph provides a basic view of how species differ in their song rates for a given air temperature.
Several graphs are available at the Singing Insects of North America website for helping to determine what species is singing based on the number of song pulses per second vs the air temperature. Another method for comparisons is to use song pulses per second vs frequency.
For trilling species in the nigricornis group (argentinus, celerinictus, forbesi, laricis, nigricornis, pini, quadripunctatus, walkeri): https://orthsoc.org/sina/s576lw63.pdf
For trilling species in the varicornis (californicus, texensis and varicornis): s576lsc13.pdf (orthsoc.org)
Another basic resource (limited recordings for some species, but gives a nice ballpark graph):
Here is an updated chart which includes Oecanthus californicus pictipennis. There are a limited number of recordings, but it gives a visual for how each species compares to others.
For trilling species in the niveus group (exclamationis and niveus): :https://orthsoc.org/sina/s576lw63.pdf
For chirping species in the rileyi group (alexanderi, fultoni and rileyi): https://orthsoc.org/sina/s576lwc10.pdf