One Last Look Back

by Carl Strang

My recent blog posts have shared highlights of this year’s field season, as I searched for singing insects in the 22-county area I define as the Chicago region. Those accounts haven’t told the whole story, though, and I have a few last photos to shake out of the bag. These fill out some of the experience of doing this kind of regional study.

For instance, other animals have enhanced the delight.

The chalk-fronted corporal is a dragonfly I have encountered only in the northern portion of the region, in this case at the Lulu Lake Nature Preserve in northern Walworth County, Wisconsin.

Walsh’s grasshopper was a new one for me. Not a singing species, but an interesting find at the Poverty Prairie in DuPage County’s Waterfall Glen Forest Preserve.

Turkey vultures assemble at dusk on the Culver, Indiana, water tower. My travels take me back to my home town a few times each season.

Interesting and beautiful scenes are to be found in the relatively undisturbed wild areas which are my main destinations.

An early evening rainbow at Conrad Station in the Indiana Kankakee Sands presaged a thunderstorm-dodging drive home on July 2.

Pinholes between tree leaves cast solar eclipse shadows at Blackwell Forest Preserve. Though the moon covered around 90% of the sun at peak, I detected no change in singing insect activity.

One of the more beautiful scenes was this panne in the Indiana dunes.

I had hoped to find delicate meadow katydids in the pannes. Dusky-faced meadow katydids were a good find there, but that species has a solid hold in other dunes wetlands.

The Pembroke Savanna in the Illinois Kankakee Sands is one of my favorite sites.

I believe these white pines at Warren Dunes State Park in Berrien County, Michigan, are the same ones where Richard Alexander found treetop bush katydids in 1971. He described the trees as small, but all are tall now. They still foster pine tree crickets, but I did not find any bush katydids.

I ended up with 115 county records for the season, totaling all newly found singing insect species over all the counties.

So far, I have found sprinkled grasshoppers only in oak savannas on sand soils.

Dusky-faced meadow katydids at the Indiana Kankakee Sands were a Newton County record.

This curve-tailed bush katydid at the Jasper-Pulaski Fish and Wildlife Area in Indiana provided a Jasper County record for my study.

I found a healthy population of long-tailed meadow katydids, including this brown-legged male, at Ferson Creek Fen in Kane County.

The Ferson Creek population also had green-legged variants, including this female.

Lisa Rainsong, Wendy Partridge and I drove south to Loda Prairie to check out the bush cicadas there. I concluded this year that the species does not occur in the Chicago region.

This Texas bush katydid was singing in early October at Springbrook Prairie Forest Preserve, DuPage County. I had an observation of this species on October 17, my latest ever in the region.

Most of the long winter remains, and as I compile data, write reports, and visit museums, I will be looking forward to another collection of rich experiences as I resume my field study in 2018.

 

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Bush Cicadas

by Carl Strang

Illinois has lost nearly all the remnants of its original prairie. Thanks to the efforts of conservation agencies and private organizations you can find prairies to enjoy, but these are restoration projects for the most part. Restored prairies are nice gardens, but they lack a significant portion of the animal life. It’s a mistake to assume that “if you build it they will come.” Too many obligate prairie insects and other animals are not good dispersers. The highest priority has to be preserving the remnants, when there is a choice between devoting resources to that or to developing restorations.

A case in point is the prairie cicada, which I have featured here in the past. Another is the bush cicada. I made a trip south of the Chicago region last week to get some experience with that species, so I would know what to listen and look for in my 22-county survey area. A 2-hour drive took me to the southern fringe of Iroquois County, to the Loda Prairie State Nature Preserve.

This remnant is only 12 acres, but its quality is excellent.

This remnant is only 12 acres, but its quality is excellent.

The term “charismatic fauna” is over-used. The bush cicada is the first Illinois insect I have encountered to which I would apply that term.

For one thing, they are big and colorful.

For one thing, they are big and colorful.

They also are noisy like the other species in genus Neotibicen (formerly Tibicen, the change justified in a paper just out this year from the UConn cicada group plus an Australian researcher). I was pleased to find bush cicadas are fully as audible as our familiar Neotibicen species.

Linne’s cicada, for instance.

Linne’s cicada, for instance.

The song is like a slowed lyric cicada song, the pulse rate closer to that of Linne’s but with sharp, separate pulses. The singing was in bouts, with sometimes 10 minutes of silence between, so that the males seemed to cue their singing off of one another. They also were very active, many of the males flying to a new perch after every song. Though their flight generally was well controlled, once one bounced off the side of my head.

A male bush cicada in full song.

A male bush cicada in full song.

In the following days I sought them in several Chicago region counties, without success. The silence of those prairie remnants, some suffering from invasion by gray dogwood and other problem plants, was a sad contrast to Loda Prairie. In fairness, though, the bush cicada is primarily a southern and western species that may never have reached into the Chicago region. That won’t keep me from continuing to seek it here, though.

Hypothetical Cicadas and Grasshoppers

by Carl Strang

Thanks to two publications, one very new and one very old, I have been able to fill out my list of singing insects that may occur in the Chicago region by adding possible cicada and grasshopper species. The new reference is a monograph published last year by the Entomological Society of America, The Cicadas (Hemiptera: Cicadoidea: Cicadidae) of North America North of Mexico, by Allen F. Sanborn and Maxine S. Heath. There is not a lot of natural history information in it, as its focus is on sorting out species and their relationships, but it is complete in its species coverage and at least outlines the range for each. It allowed me to add three possible cicadas to my list. Two of them are tallgrass prairie specialists that are known in Illinois but may not occur this far north: the common grass cicada (Cicadetta calliope), a tiny early season species, and the bush cicada (Tibicen dorsatus), a late season species. The third added cicada, Walker’s cicada (Tibicen pronotalis), is a large insect of woodlands along streams.

The old reference is W.S. Blatchley’s Orthoptera of Northeastern America with Especial Reference to the Faunas, of Indiana and Florida. This one was published back in 1920, and is available as a 2012 reprint by the Forgotten Books company. The text is generally readable, but somewhat faint. The taxonomy and nomenclature for the grasshoppers have been remarkably stable over time, and most scientific names haven’t changed. I was able to make the necessary updates by referring to the most recent popular guide to grasshoppers, katydids and crickets by Capinera, Scott, and Walker. Blatchley’s book contains considerable natural history information, and is reminiscent of the Bent’s Life Histories of Birds in its style.

There are two subfamilies of singing grasshoppers. The stridulating slantfaced grasshoppers, subfamily Gomphocerinae, sing while perched or resting on the ground, lifting and lowering their back legs to rub them against the wings, producing a rapid zuzz-zuzz-zuzz sound that is distinct from other insect songs, but to my ear this stridulation seems much the same in different species. The only one for which I have a photograph is a northern species.

Thomas’s broad-winged grasshopper at Whitefish Point on the Upper Peninsula of Michigan.

Thomas’s broad-winged grasshopper at Whitefish Point on the Upper Peninsula of Michigan.

That grasshopper does not occur as far south as our area, but another member of its genus, the sprinkled broad-winged grasshopper (Chloealtis conspersa) is one I’ll listen for, along with 7 other candidates in this subfamily. Though their songs probably are much the same, their habitats and details of their appearance are different.

The other singing subfamily of grasshoppers is Oedipodinae, the band-winged grasshoppers. These produce their sounds in a different way, crepitation, by rattling or rubbing together their wings in flight. The potential additions to the local list number a dozen species. One of these also was prominent at Whitefish Point.

A pair of clear-winged grasshoppers, Camnula pellucida

A pair of clear-winged grasshoppers, Camnula pellucida

The literature suggests more variation in the sounds produced by the crepitation method, but these grasshoppers are flying when they sing, and so should be easier to locate.

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