Closing the Book on Prairie Cicadas

by Carl Strang

The prairie cicada is a small (1-inch) insect that occurs in a few remnant prairies in northeast Illinois. Work by Dennis Nyberg and associates at the University of Illinois Chicago has revealed much of what is known about them in the state. I first gained experience with this species a few years ago at the UIC’s Woodworth Prairie in northern Cook County, then quickly discovered them in two DuPage County locations. I expected then that I would find them consistently in prairie remnants, but this has not proven to be the case.

Prairie cicada, June 2017

Recently I finished checking the last of the remnant prairies I know about in the Chicago region, and have not added any more locations to the UIC group’s 8 sites (they also listed 3 sites in downstate counties). I have not found them anywhere in the region’s Indiana or Wisconsin counties.

All the sites are small, so all the populations are small and vulnerable. Mated females do not disperse beyond their little prairie plots, as far as anyone has been able to determine. If the species is to survive in the region, the landholders (mainly forest preserve districts and railroads) will need to continue managing those sites so that the prairies can persist, and prairie cicadas with them.

Closing the Book on Protean Shieldbacks

by Carl Strang

The protean shieldback is the most common native predaceous katydid in the Chicago region. Because of their broad diet, they can develop quickly in the spring. They begin singing in June, the males broadcasting their extended, high-pitched rattles in open woodlands, as well as prairies with at least a little woody vegetation.

Male protean shieldback in singing posture.

At first, they begin to sing in the late afternoon from hidden locations near the ground. When it becomes dark, they climb up onto open perches, often on woody stems. As their season progresses, they begin to sing later, until a few begin at dusk and most wait until dark.

This year I learned that they are more abundant than I had realized. I need the SongFinder, a pitch-lowering electronic device, to hear most of them. With that final lesson, I sought them out in portions of my 22-county Chicago region where I had not found them before. That mission was successful, the final 15 counties resulting in some late-night returns home. At this writing, they still are going strong.

A Mystery Solved: Miogryllus!

by Carl Strang

In 2014 I first heard what sounded to my ear like a singing striped ground cricket, but it seemed too early in the season. It was June 21, at Hoosier Prairie Nature Preserve in Lake County, Indiana. I made a recording, then moved on to the Indiana Kankakee Sands, where I heard it again. Though these sites are a bit south of my DuPage County home, I didn’t hear striped ground crickets in DuPage until July 13. The next year I heard the same odd songs, this time at the Midewin National Tallgrass Prairie, in the middle of Will County, immediately south of DuPage. This was even earlier, on June 10. Again I made a recording. And again, I did not hear striped ground crickets in DuPage until, as it happened, July 13. In 2016 I went down to Midewin on June 28, and heard the same early, striped-ground-cricket like songs. This year, the same story, Midewin, June 23. This time, though, it seemed to me that the songs were not quite right for striped ground crickets. They seemed too precise, too even and strong. Here is a recording I made in the same location on June 28:

I went back and listened to my earlier recordings, reviewed my list of hypothetical singing insect species for the Chicago region, then checked reference recordings of their songs. The early songs did sound different from my recordings of later-season striped ground crickets, an example here:

The odd, early songs seemed to be a match for one of the hypotheticals, the eastern striped cricket, Miogryllus verticalis. Furthermore, references indicated that M. verticalis is an early season species, most abundant in June. I drove back down to Midewin on June 28. Trying to zero in on the singers was very frustrating; they seemed to have a ventriloquial quality. Eventually I flushed out and captured a female cricket near one of the singing mystery males. Looking through the clear plastic cup that held her, I could see that she was indeed an eastern striped cricket. I took a couple photos looking down into the cup. It was well that I did, because when I tried to get her positioned for a shot from the side, she gave me the slip and I was unable to recapture her.

Female eastern striped cricket, dorsal view

She was just a little smaller than a spring field cricket, which species was sharing the grassy meadow where Miogryllus were abundant. This confirms that eastern striped crickets are established in the southwestern portion of the 22-county area I define as the Chicago region. They would seem to represent yet another example of a range extension northward by a singing insect species.

Bioblitz 2017

by Carl Strang

This year’s bioblitz in the series organized by the Indiana Academy of Sciences took place on June 10-11 at the White River Woods and McVey Memorial Forest, two sites near Muncie. This early in the season I did not expect much in the way of singing insects. Spring trigs were common, so I gained more experience with them, but there was a surprising lack of spring field crickets.

Green-striped grasshoppers still were displaying at McVey.

A Roesel’s katydid at White River Woods

I joined Jeff Holland’s Purdue University group at their light station in the forest at McVey, assisting as a moth spotter. A few photos from that night follow.

Banded tussock moth

Io moths, when resting, do not show their dramatic hind-wing eye spots.

Barred granite

A few walnut sphinxes were attracted to the light.

A couple black-sided pygmy grasshoppers also made an appearance.

Male black-sided pygmy grasshoppers have a distinctive white, black and brown pattern.

Females are all dark. The pygmy grasshoppers are distinguished not only by their small size, but also by the pronotum’s extension over much of the abdomen.

 

Closing the Book on Sulfur-wings

by Carl Strang

The sulfur-winged grasshopper is an early season species that I wanted to close out this year, in my regional survey of singing insects. Though it probably occurs in all 22 of the counties in my survey region, it is common only on soils heavy in gravel or sand. I targeted 3 counties with such soils where I had not yet found this crepitating (wing-rattling) grasshopper: Walworth in Wisconsin, LaPorte in Indiana, and Berrien in Michigan.

Success came first at the Lulu Lake natural area in Walworth County. I did not find it in the Nature Conservancy portion of the property, but gravel-hill openings in the forest on the state nature preserve side proved to have a good population.

One of the series of photos documenting sulfur-winged grasshoppers at Lulu Lake.

Subsequently I found them in the Lake Michigan coastal zone in LaPorte and Berrien Counties. In the process I learned a final lesson from the grasshoppers: they don’t like loose dune sand, and need to be sought a little farther inland, where plants and the accumulation of organic matter have made the soil more stable. That closes the book on sulfur-winged grasshoppers as far as my survey is concerned, and I will put my time into other species at this point of the season in future years.

The updated Chicago region sulfur-winged grasshopper map, marking counties where I have found it.

 

Searching for Life

by Carl Strang

This spring I have been pressing a search for coral-winged grasshoppers, and it has been disappointing. This singing insect historically was found in a few locations in my 22-county survey area, almost always in May, but none of those locations proved to have the species. Other places that match the habitat descriptions in the literature likewise have been lacking in coral-wings.

Though depression as a response to this experience has been tempting, an antidote has been thoughts about SETI. Many people, years of time, and much expensive technology have been devoted to the Search for Extra-Terrestrial Intelligence. Furthermore, despite much thought and searching, life of any sort beyond the Earth thus far has been elusive. Balanced against all that, my frustrated search for a species that globally is in no danger seems a trivial matter.

In compensation, I have been getting into some beautiful areas and seeing wondrous sights.

For example, I found hairy puccoons and common blue-eyed grass at Illinois Beach State Park on May 13.

Wood betony also was in peak bloom on the 13th.

From above, wood betony has a delightful pinwheel shape.

Near the edge of the savanna at Illinois Beach State Park, this dung beetle busily rolled a deer fecal pellet.

An Indiana site added Indian paintbrush to the wildflower mix.

 

The Miller Woods Trail of Indiana Dunes National Lakeshore was flanked by banks of wild lupines on May 16.

Scattered hairy puccoons provided delightful contrast with the lupines.

With such wonderful life all around, it’s hard to be too disappointed by the failure to find a single species.

 

Museum Visits

by Carl Strang

Planning for the coming singing insects field season has been one of my major occupations this winter. I am looking forward to visiting many new sites, and hope to find some of the species that historically occurred in the Chicago region but which have eluded me so far. Part of that process has been to visit insect collections, gaining information on those species and taking photographs that will help me recognize them.

While at the Purdue University and Illinois Natural History Survey collections, the two museums I have visited so far, I also photographed specimens of species that I have heard but not yet photographed in the field. This will enhance next year’s edition of the guide.

The northern mole cricket is one of those species. This front-end view shows why that cricket is well named.

A note on one specimen said it was collected while flying around in someone’s garage. I had not been aware that northern mole crickets can fly.

Another plan for the upcoming guide is to add pages for the species that have been documented in the Chicago region, but which I have not yet found. Researching those species is getting me better prepared to find them.

There is a Kankakee County record for the common virtuoso katydid, in or near the Illinois Kankakee Sands preserve. That is one species I will be seeking this year.

Walker’s cicada has been collected in a few locations around the region. I need to be alert for its distinctive song in the coming season.

The coral-winged grasshopper will be one of the earliest species for me to seek this spring. They overwinter as nymphs, and have been found mainly in May in past years. I have several locations to check.

The large spots on the sides of the wings, along with the golden wing edges and brightly colored hind wings, are distinguishing features of coral-winged grasshoppers.

Female delicate meadow katydids have unusually long ovipositors. This example will help me distinguish them from green-faced individuals of the dusky-faced meadow katydid. I have not given up hope for the delicate meadow katydid in the region.

Another species I still hope to find is the slender conehead. This one, collected at Illinois Beach State Park in 1906, shows the main distinguishing features of that wetland species: the front of the cone is all black, and there is a right-angle bend in the contour of the pronotum’s posterior edge.

All of this is getting me fired up, but I still have two months to wait. Maybe another museum visit is in order…

 

Singing Insects Guide 2017

by Carl Strang

The main product of my singing insects research is a guide, Singing Insects of the Chicago Region. Each year I update the guide with new information from the field season just past. The Chicago region for this project includes 22 counties from southeastern Wisconsin around to Berrien County, Michigan. Singing insects are defined here as the cicadas, crickets, katydids, and members of three grasshopper subfamilies with sound displays that people can hear (though the songs of some are so high pitched that only young people can hear them unaided). There are around 100 species, though some I haven’t found outside historical records.

title-page-2017

The guide is available for free as a highly compressed PDF document that nevertheless occupies over 5MB, thanks to the many photos. There are maps showing current and historical county records, graphical devices indicating seasonal and time-of-day information, and descriptions of the insects and their songs. Information is presented as well on conservation concerns and ongoing range expansions. To receive the current version of the guide and get on the mailing list for future updates, send your request to me at wildlifer@aol.com.

Singing Insects Wrap-Up

by Carl Strang

October’s cold gradually is silencing another year’s array of singing insects. In recent weeks I have made some final trips to squeeze just a little more data out of the season.

In early September I succeeded in catching an Autumn yellow-winged grasshopper with actual yellow wings (most of them in the region have had red-orange hind wings).

In early September I succeeded in catching an Autumn yellow-winged grasshopper with actual yellow wings (most of them in the region have had red-orange hind wings).

On October 5 I made a final trip up to Illinois Beach State Park, and found some stripe-faced meadow katydids still singing.

On October 5 I made a final trip up to Illinois Beach State Park, and found some stripe-faced meadow katydids still singing.

By then, of course, they had developed their full color.

By then, of course, they had developed their full color.

I was able to complete a photo series on the species with some cerci shots.

I was able to complete a photo series on the species with some cerci shots.

On October 11 I returned to Gar Creek Forest Preserve in Kankakee County and made more recordings. I did not find any more Cuban ground crickets crossing the trail, but was surprised by several variegated ground crickets doing so.

I had never before seen a variegated ground cricket, like this male, wandering in the open.

I had never before seen a variegated ground cricket, like this male, wandering in the open.

This female has an interesting pattern of pale dashes on her wings.

This female has an interesting pattern of pale dashes on her wings.

It’s reasonable to assume that they walk about at night for most of the season, but like many singing insects extend their usual nighttime activity into the day as temperatures cool. I was glad to get the visual confirmation that this species is at the site along with the (probable) Cubans.

Probably my last singing insect photo series for 2016 was of this spotted ground cricket at St. James Farm on October 18.

Probably my last singing insect photo series for 2016 was of this spotted ground cricket at St. James Farm on October 18.

 

Making a Case 3: Northern Wood Cricket

by Carl Strang

Last year I concluded that I had found northern wood crickets (Gryllus vernalis) in the Winamac State Fish & Wildlife Area in Pulaski County on June 13, based on habitat and sound recordings. In 2016 I returned to that site on May 29, but did not find them singing. On June 3 I heard Gryllus crickets chirping along the Marquette Trail, near the east border of Lake County, Indiana. All were in forest or savanna areas, the singers in deeply layered black oak leaves, usually in shade under black oak trees but some in isolated collections of leaves surrounded by sand.

One of the woodland crickets’ song sites near the Marquette Trail.

One of the woodland crickets’ song sites near the Marquette Trail.

None were in the open grassy areas favored by spring field crickets (G. veletis), even though such habitat was close by. I recorded two of these individuals, and later in the season recorded field crickets in meadow and prairie habitats favored by veletis but where vernalis would not be expected, plus another individual that by habitat should be vernalis, at the Kankakee Sands site in Kankakee County, Illinois.

The results seemed contrary to what would be expected from previous studies.

The likely vernalis (forest) had lower chirp rates than likely veletis (grassland).

The likely vernalis (forest) had lower chirp rates than likely veletis (grassland).

The number of pulses per chirp was unhelpful, with likely veletis ranging 2-4, likely vernalis 3-4. Linear regressions of the two sets of data show, perhaps significantly, the same slopes of chirp rate increase with temperature (physiology of closely related species expected to show a similar response to temperature). The linear regressions indicate that, for a given temperature, forest cricket chirp rates are 1.44/second less than grassland chirp rates. All data I can find in the literature for vernalis were collected from that part of their range where they are sympatric with the southern wood cricket (G. fultoni). Jang and Gerhardt (2005. J. Evol. Biol. 19:459–472) found that fultoni song characteristics differed between populations sympatric with vernalis and those allopatric to that species. They did not study allopatric vernalis. As my recordings may be the only ones that have been made where vernalis is allopatric to fultoni, and given the clear difference between recordings in habitats for likely vernalis and likely veletis described above, so far it appears that habitat, chirp rates and temperatures will be enough to establish the presence of vernalis. The major obstacle to finalizing this conclusion is confirming the identity of the forest crickets. So far I have been unsuccessful in efforts to catch or even see one. Next year I need to continue making recordings and trying to catch and measure suspected northern wood crickets.

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