by Carl Strang
The Dead River, in Illinois Beach State Park, is so named because most of the time it appears not to be flowing. It ends just shy of the edge of Lake Michigan, a sand bar between the two. Reportedly there are times when enough water comes into it that it breaks through this narrow barrier. The area south of that river is highly protected, and to enter it I needed a permit from the Illinois Nature Preserves Commission.
My main goal was to survey the area for wetland singing insects. This was one of my last hopes for finding slender coneheads, but sadly there were none. I am beginning to think they have gone extinct in Illinois. On a much brighter note, I found that the area harbors a huge population of stripe-faced meadow katydids.
Illinois Beach remains the only place where I have found this wetland katydid, which even historically was never widely distributed.
I also heard a little chorus of nimble meadow katydids, out in the middle of a river offshoot in a patch of deeper-water arrowheads. There probably are other such groups elsewhere in the area. I plan to get a better idea of their numbers next year. This is the second place I have found them in the region, and the first for Illinois. I spent several days in my kayak this season searching for nimble meadow katydids in places in Illinois and Indiana where they were known in earlier decades.
I have found them among pickerel weeds and arrowheads, and historically they were known in patches of water knotweeds.
I suspect that the turbulence created by power boats favors the heavier plants that the insect apparently abhors. I wonder if Illinois Beach State Park also may harbor the last Illinois population of nimble meadow katydids. I have a few more places to check next year.