by Carl Strang
The sphagnum ground cricket was a species I had sought but failed to find in DuPage County last year. Apparently low vernal pool areas in our woodlands are not sufficiently close to the sphagnum habitat the species requires, and as we have no sphagnum in DuPage I would need to look elsewhere. When my plans for Illinois Beach State Park were thwarted by the south unit’s closure, I decided to move on from the north unit (where I had been successful in my search for gray ground crickets) to Volo Bog State Natural Area.
The outermost zone of the bog was not promising. There was no sphagnum that I could see, mainly marsh plants, with the prominent singing insects being black-legged meadow katydids and Carolina ground crickets.
As I entered the next concentric ring of habitat, working my way toward the bog’s center, a mix of shrubs was dominant. The black-legs and Carolinas petered out. I began to see sphagnum moss.
At first I heard mainly Say’s trigs, but it seemed there was something else. I got out the SongFinder, and its frequency-lowering function allowed me to identify a second, fainter, more rapid trill. When I then removed the headphones I found that I could pick out the second trill, which matched my memory of reference recordings of sphagnum ground crickets. I got down on my hands and knees at the edge of the boardwalk, probing the sphagnum lightly with my fingers, and that was all it took to get some photo ops.
Adults seemed mainly black.
There were so many singing at once that I was not able to pick out the ends of any trills. The song seems very like that of the gray ground cricket, but fainter, being a very rapid, level, high-pitched trill (more rapid than those of Allard’s ground crickets or Say’s trigs). I am guessing that the gray ground cricket needs to be louder in its more open, wind-swept dune habitat.