by Carl Strang
After more than ten years of study, I still have not found several species of singing insects that historically were known in the Chicago region. One of these was the prairie meadow katydid, one of the smaller members of its group. On August 16, Wendy Partridge and I were checking out the bike trail near the nature center at Illinois Beach State Park. Through the SongFinder, which allows me to hear high pitches, I heard faint rapid ticking sounds which, when heard from a closer position, resolved into brief buzzes. They were mechanical and katydid-like rather than cricket-like in quality, and didn’t match anything I had heard before. Wendy, with her unusually good hearing, barely could pick them up. Later, checking reference recordings, I decided they fit the song of the prairie meadow katydid. They were not in the habitat I would expect, however, being in dense vegetation where grasses were mixed with woody plants and forbs, generally shaded. That katydid species has been known to occur in that park, however.
Then on September 27 I caught and photographed a small female meadow katydid in a relatively dry portion of the Gensburg Prairie in Cook County.
Posterior portion of the Gensburg Prairie female.
Her color didn’t seem quite right for a short-winged meadow katydid, which is a common species at that site especially in the wetter portions. Studying the photos, and looking back at references, I have decided that she was a prairie meadow katydid. Along the way I looked back at all my photos of short-winged meadow katydids, and found two other individuals that met at least some of the criteria for prairie meadow katydid, one in 2011 at Mayslake Forest Preserve, and one in 2014 in the savanna woodland at Illinois Beach State Park.
The Mayslake female
The Illinois Beach State Park female
All three have curved ovipositors that are slenderer in proportion than in a typical short-winged meadow katydid.
Typical female short-winged meadow katydid
All three also have femoral patterns in which there is a lengthwise pair of lines, as in the short-winged, but have ladders of narrow crossbars rather than being clear between them as in typical short-winged. There is enough overlap in body length, according to references, that it is not a consideration in comparing those two species. The ovipositors are too short, and the femur patterns wrong, for straight-lanced meadow katydid to be a consideration. The Mayslake female is different from the other two individuals in three possibly significant ways: the femoral ground color is green rather than brown or tan, the wings are much longer, and the front of the head does not appear to rise so much (this last being a difference mentioned by W.S. Blatchley in his classic Orthoptera of Northeastern North America, which gives unusually detailed descriptions of species).
Anterior portion of the Gensburg Prairie female. Note the abrupt rise of the tip of the head when viewed from the side.
Dorsal view of the Gensburg Prairie female. Blatchley describes the wings of prairie females as covering only one-fourth of the abdomen, two-thirds in short-winged females. Furthermore, the tip of the head, when viewed from above, is relatively wide after an inward bending of its sides, expected from Blatchley’s description.
Compare this short-winged meadow katydid, with its relatively narrow and straight-sided tip of the head, to the previous.
Side view of the same male as in the previous photo. Again, note the lack of a rise in the top of the head profile.
Blatchley also believed that prairie meadow katydids occur only in “raw prairie,” a description which applies to Gensburg and Illinois Beach but not to Mayslake. I am inclined to regard the Mayslake individual as an anomalous short-winged meadow katydid, but pending study of museum specimens, am naming the other two prairie meadow katydids.