Stripes

by Carl Strang

Identifying species of small meadow katydids (genus Conocephalus), especially nymphs, can be challenging. Most adults are readily sorted out, especially males if you can get a good look at the cerci or claspers at the tips of their abdomens.  Females are trickier, but their ovipositors often allow distinctions to be made. I’ve decided to take a shotgun approach in my survey at Mayslake Forest Preserve, sweep sampling on a weekly basis and taking photos of as many individuals as I can. Last week I noticed something that is potentially helpful.

This is an unambiguous male short-winged meadow katydid. Cerci are right, lots of orange color around the abdomen tip, short wings, small size.

As I compared my many photos, I found that the color pattern on the sides of the hind femurs drew my eye. Notice the band of clear green color bounded by brown stripes on either side. Here’s a female, again clearly a short-winged.

Though she may be an instar short of adulthood, this one has the ovipositor of a short-winged.

Again the color pattern on the femur appears. I did an Internet search, and except for some photos from Texas, short-winged meadow katydids show this striping pattern across eastern North America. Then I began to compare other species. I started with another familiar one, the slender meadow katydid.

This male I photographed last year has clear green femurs, without the stripes.

Again an Internet and reference book search showed consistently clear green femurs on this species. However, I was surprised to find that a female I had identified a couple years ago as a slender meadow katydid had the femur stripes.

The long wings fooled me. The ovipositor actually rules out slender meadow katydid. This was a rare individual short-winged meadow katydid with long wings.

Next I turned to two species I have been seeking, which could overlap with the short-winged’s habitat. Straight-lanced meadow katydids in references and Internet photos lack the short-winged’s stripe pattern, instead often showing a diffuse blackish zone down that face of the femur. I went to photos of females I tentatively had identified as that species last year.

This one not only has an ovipositor much longer than the femur length, and lacks orange at the abdomen tip, but shows a femur color pattern different from the short-wingeds’ and consistent with straight-lanced reference photos. In fact it appears that the diffuse black zone is the same as the upper dark stripe on the short-winged, but differing in color and not sharply bounded. The lower stripe is there as well, but just as a trace of a line. I believe this individual may indeed have been a straight-lanced meadow katydid.

Others prove, on closer inspection, in fact to have been short-wingeds.

This young nymph has an ovipositor marginally longer than the femur, but has an instar or two to go until maturity and looks awfully orange around the abdomen. The femur color pattern clearly ties it to short-wingeds, and I think that is where this insect belongs.

The other species I need to sort out is the prairie meadow katydid. Few photos of this one are out there. In some there is no stripe pattern like the short-winged’s, in some there is a hint of one. For now I will need to focus on cerci (straighter, more pointed and with distinctly longer teeth than the short-winged male’s) and ovipositors (proportionately more curved than the short-winged female’s). I am encouraged, however, to continue looking for details of color pattern that might provide short-cuts to field identification at least in regional or local populations.

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