Making a Case 2: Prairie Meadow Katydid

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.

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 Mayslake female

The Illinois Beach State Park 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

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.

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.

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 common meadow katydid, with its relatively narrow and straight-sided tip of the head, to the previous.

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.

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.

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2 Comments

  1. Norman Levey said,

    October 12, 2016 at 6:58 am

    I have such difficulty hearing meadow katydid calling songs (except for the low end of the spectrum) that I have this crazy ambition to go out and make high definition recordings to create sonograms in software. Have you tried this? I have done some sonogram matching with tree cricket songs on the SINA site. One needs very quiet environments to do this without the focus of a parabolic microphone kit and I have had to “photoshop” my sonogram screen grabs to increase contrast and remove some visual background noise.

    Great post. Meadow katydids are tough! – Norm Levey

    • natureinquiries said,

      October 13, 2016 at 6:21 am

      Thanks, Norm. I can’t hear any Conocephalus songs any more unaided, and some Orchelimum songs are faint to me. Some, like the long-tailed and straight-lanced meadow katydids, are relatively easy to kick up and I don’t need to hear them. For the others, the SongFinder is an indispensable tool. Though some advanced students of the sounds use parabolic reflectors for recording, I find the shotgun mike to be adequate, and sometimes even experts like Wil Hershberger use them without the reflector. As long as the microphone has the sensitivity to reach the high frequencies, recordings can be made for analysis. Of course, with either setup, you need to know where to aim. I find that with at least some of them, the headphones close out other sounds to the point where I can faintly hear even Conocephalus being picked up with the mike. Of course, I previously used the SongFinder to get a reasonably close idea of where the singer is sitting.


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