Why the Green Face?

by Carl Strang

This has been a good year for finding additional populations of dusky-faced meadow katydids, a wetland species that has caused me some concern. Once regarded as a ubiquitous marsh insect, they have proven hard to find. In the Chicago region they occur only in remnant marshes and wet prairies with significant amounts of native grasses (though Lisa Rainsong recently reported an Ohio population living in arrowheads), and little or no invasive wetland vegetation. They apparently don’t care for sedges. Such places have become few and far between. So far I have found no evidence of dispersal into restored wetlands.

Dusky-faced meadow katydid, from a newly discovered population at Houghton Lake, a Nature Conservancy site in Marshall County, Indiana.

Dusky-faced meadow katydid, from a newly discovered population at Houghton Lake, a Nature Conservancy site in Marshall County, Indiana.

That said, I have been pleased to find several more populations hanging on in the region. In addition to Houghton Lake, I have found them in two locations in Lake County, Indiana, and have found that they occupy a much larger area at Midewin National Tallgrass Prairie than I realized.

For a time I thought I also had re-found delicate meadow katydids at the Indiana Dunes National Lakeshore. Back in 2012 I got a fuzzy photo of what I thought was that species:

She was gone before I could get anything clearer. The grass-green face seemed to point to delicate meadow katydid.

She was gone before I could get anything clearer. The grass-green face seemed to point to delicate meadow katydid.

When Lisa, Wendy, Wil and I returned to that site in August, we found more green-faced individuals. I also started seeing them elsewhere.

I labeled this photo as a delicate meadow katydid; the green face seemed unambiguous.

I labeled this photo as a delicate meadow katydid; the green face seemed unambiguous.

There were problems, however.

Though some tiny speckles reportedly can occur on the faces of delicate meadow katydids, the green-faced ones often showed the reddish networks typical of dusky-faced.

Though some tiny speckles reportedly can occur on the faces of delicate meadow katydids, the green-faced ones often showed the reddish networks typical of dusky-faced.

This green-faced male has especially heavy reddish markings.

This green-faced male has especially heavy reddish markings.

Also, the ovipositors were too short. They seemed relatively straight, but clearly were less than half the length of the femur.

Also, the ovipositors were too short. They seemed relatively straight, but clearly were less than half the length of the femur.

The songs of some of the males had relatively short intervals of ticks between relatively short buzzes. The ticks all were single, however.

The principal paper published on this species group is by Edward S. Thomas and Richard Alexander (1962. Systematic and behavioral studies on the meadow grasshoppers of the Orchelimum concinnum group (Orthoptera: Tettigoniidae). Occasional Papers of the Museum of Zoology, University of Michigan No. 626:1-31). After studying it closely I have to conclude that all these green-faced individuals are dusky-faced meadow katydids. Thomas and Alexander mention that dusky-faceds can have green faces occasionally (apparently more often around the southern end of Lake Michigan than in the species as a whole). The ovipositor length in females, and the lack of doubled ticks in the males’ songs, seem conclusively to rule out delicate meadow katydids in the individuals I have found. That’s a shame, because it may mean that the species has gone extinct in the region. But I’ll keep looking…

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