Roesel’s Katydid in Michigan

by Carl Strang

In recent years, collaboration between Scott Namestnik and I, augmented by observations from several others, has resulted in a much improved understanding of the range of Roesel’s katydid, a European import which has spread from Quebec through a large area of SE Canada and the northeastern U.S. We have connected the northeastern katydids to those in Indiana and Illinois, and miscellaneous other observations have documented the insect in Iowa and Wisconsin. Here is the current map from the Singing Insects of North America (SINA) website.

The current map for Roesel’s katydid in SINA.

As you can see, the Lower Peninsula of Michigan is a gaping hole in the species’ range, which didn’t make sense, so this year we resolved to do some searching there. Scott struck first, finding Roesel’s in Kalamazoo County. A goal of my trip into Michigan last week was to look for Roesel’s farther north. Thursday was cool and rainy, and I didn’t have much luck. However, after moving into my room at the Grayling Ramada I went for a short walk in the wooded area behind (west of) the motel, and was surprised to hear a few late afternoon buzzes that to my ear were identical to Roesel’s. They were in an open woodland with ground cover dominated by bracken.

Part of the area with possible Roesel’s.

I also heard a crepitating grasshopper that I thought might be the greenstriped, and a stridulating grasshopper that probably would be new to me. The next day, after the Kirtland’s warbler tour, I returned, but the weather was cool and the possible Roesel’s were singing only at great intervals. I never got a look at one, though I photographed a couple grasshoppers. The crepitating one indeed was the greenstriped.

This one landed on the parking lot and posed.

The only other mature grasshopper species I was able to see had long wings and probably does not stridulate.

My best guess at an identification is that this is the little pasture grasshopper, an early season species that has a broad habitat range.

I couldn’t wait around on the off chance that things would warm significantly. My identification of Roesel’s is likely but not certain. The only other singing insects with a buzz remotely like that of Roesel’s are some of the coneheads, but they are much louder and later in the season. Unless there is something I don’t know about, these should in time prove to be Roesel’s. I shifted south, to the State Road 46 region. This area is just south of the forests and marshes that dominate the northern part of the Lower Peninsula. I stopped in the little village of Elwell, parking at an access point for the Fred Meijer Heartland Trail. I walked the trail back east a mile.

Fred Meijer Heartland Trail

I heard no Roesel’s on the way out. The trail intersected Rich Road, which looked promising, and indeed I found several Roesel’s singing just south of the trail crossing.

Rich Road proved rich indeed for my target insect.

I got looks at 2, one a short-winged variant and one either long-winged or mid-length.

I wasn’t able to photograph any of the Michigan Roesel’s. Here is a long-winged one in Illinois.

The only insect I photographed there was an obliging bronze copper.

This butterfly occurs in DuPage County, too, but is not particularly common.

On the way back to the car I found a long-winged Roesel’s singing along the trail. So, we have confirmed them in southwest and mid-central Lower Michigan, with likely ones at Grayling as well. That hole in the katydid’s range is, as we expected, at least partially filled.

The SINA map showing the three locations mentioned here.

That concludes my research on this particular question, at least for now.

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