by Carl Strang
Spotted ground crickets have been a challenge for me. There are old records of them in several of the counties I am surveying for singing insects, but I had not found them prior to this year. Prompted by Lisa Rainsong’s results from the Cleveland area, I made a goal of finding them this year. I knew what the problem was: to my ear, recordings of their songs are very similar to those of Carolina ground crickets, which I have found throughout the region. Here is one of my recordings of the latter species, made at 58 degrees Fahrenheit (all recordings in this post have been equalized to remove low-frequency background noise, mainly from traffic):
Here is another, this one at 56 degrees F.
I describe the Carolina ground cricket’s song as a continuous purr or very rapid trill, in which pulsing sections alternate with steadier trills that do not pulse.
Contrast those sounds with the following two recordings of spotted ground crickets. The first was made at around 80 degrees F.
The second was made at 71 degrees F. There is a noticeable drop in both pitch and rapidity of the pulses.
After my experience this year I feel confident that I can distinguish the spotted ground cricket’s song, but I still need to listen carefully. The pulses are regular and continuous, lacking the non-pulsing sections of the Carolina ground cricket’s song. The sound is rougher, grittier, and I would not describe it as a purr. Also, study of sonographs reveals that the spotted ground cricket actually has minute pauses between the pulses, in contrast with the Carolina ground cricket’s more continuous sound production.
So far it seems to me that spotted ground crickets prefer closed-canopy forest or woodland areas with some accumulations of leaf litter where forest floor vegetation is sparse. The soil needs to be well drained yet moist. Most commonly this seems to mean soils heavy in sand or gravel, but hillsides with denser soils sometimes have spotted ground crickets, too, and I have found them in several of DuPage County’s clay-soil woodlands.