Gensburg-Markham Prairie

by Carl Strang

One day last week I drove down to southern Cook County for singing insect survey work. I quickly found confused ground crickets for a county record in the Palos area, then proceeded to the Gensburg-Markham Prairie, which proved so fruitful that it occupied the rest of the afternoon. The dominant sound in that high-quality nature preserve was the buzzing of common meadow katydids.

The name is deceptive. This is one of the few places I have found to date where Orchelimum vulgare indeed is abundant.

The name is deceptive. This is one of the few places I have found to date where Orchelimum vulgare indeed is abundant.

There were other dry-habitat species present as well. I was able to add county records for woodland meadow katydid (my northernmost to date) and for straight-lanced meadow katydid.

This straight-lanced female was content to explore my finger and pose.

This straight-lanced female was content to explore my finger and pose.

The richest portion of the site’s singing insect fauna was the subfamily of stridulating slant-faced grasshoppers. I took lots of photos, thinking I had found the mother lode of species. When I examined them closely, however, the diversity turned out to be mainly within species, and I concluded that most of them in fact were marsh meadow grasshoppers.

Here is a classic adult marsh meadow grasshopper.

Here is a classic adult marsh meadow grasshopper.

But then there were a number of these. After much study I had to conclude that this, too, was an adult marsh meadow grasshopper.

But then there were a number of these. After much study I had to conclude that this, too, was an adult marsh meadow grasshopper.

Ditto for this one.

Ditto for this one.

Even more color variation was provided by nymphs. Again, I think they were marsh meadow grasshoppers.

This one in particular was strikingly colored.

This one in particular was strikingly colored.

And this individual seems aimed toward the pattern of the third adult above.

And this individual seems aimed toward the pattern of the third adult above.

These were my first of the species in Cook County, so they were a happy find. Two other grasshoppers also were my first for the county.

Wetter areas had plenty of short-winged green grasshoppers like this female.

Wetter areas had plenty of short-winged green grasshoppers like this female.

Prize of the day was this critter, the first spotted-wing grasshopper I have seen anywhere.

Prize of the day was this critter, the first spotted-wing grasshopper I have seen anywhere.

She wasn’t giving me good angles for photography, but fortunately I got a clear shot of the dorsal pronotum.

She wasn’t giving me good angles for photography, but fortunately I got a clear shot of the dorsal pronotum.

The inward-curving margins and their posterior big black triangles point to the two local species of Orphulella. There are two cuts in the dorsal surface, which point to O. pelidna rather than its close relative the pasture grasshopper O. speciosa.

This prairie is one I intend to visit in all portions of the singing insect season.

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