Another Season in the Books

by Carl Strang

In earlier posts I outlined the most significant finds in this year’s research on singing insects. The season was sprinkled with smaller delights, too, and I am pleased to call it successful. My game plan emphasized visiting new sites and trying to plug distributional holes for some species. I looked at 11 new sites, added 20 county records for all species combined, and closed the book on three species, i.e., I now have found them in every county or, at least, every county where I expect to find them. Those were the gray ground cricket (Allonemobius griseus), which I found at Chicago’s Montrose Park on September 6 for a Cook County record; the four-spotted tree cricket (Oecanthus quadripunctatus), which I now have documented in all 22 counties of my study region; and the oblong-winged katydid (Amblycorypha oblongifolia), which stubbornly had refused to reveal itself in LaPorte County, Indiana, until I heard a few singing on August 6 at Kingsbury Fish & Wildlife Area.

I also found new north locations for two of the species that are expanding their range from the south: the slow-tinkling trig (Anaxipha tinnulenta) at the Grand Mere Lakes in Berrien County, Michigan, and the handsome trig (Phyllopalpus pulchellus) at the northern end of Grassy Lake Forest Preserve for a Lake County, Illinois, record.

Now for a few photos of critters found along the way. I wanted to clarify the relatively early, long-trilling tree crickets I have been hearing at DuPage County’s Springbrook Prairie Forest Preserve. These proved to be a mix of four-spotted and Forbes’s (O. forbesi) tree crickets.

Forbes’s tree cricket from Springbrook Prairie, temporarily chilled for photographic purposes

I had visited Cook County’s Penny Road Pond preserve a few times before, but this year got into a large part of it that was new to me.

Texas bush katydid (Scudderia texensis), a site record for Penny Road Pond.

One of the new sites I visited was Spring Lake Forest Preserve in Cook County. As I walked a woodland trail I saw an interesting looking grasshopper, which I concluded was a sprinkled grasshopper (Chloealtis conspersa). This was the year’s second county record for the species, the first being the subject of an earlier post.

Sprinkled grasshopper nymph at Spring Lake

The remaining two photos are from a September 2 visit to Pulaski County, Indiana.

This female spotted ground cricket (Allonemobius maculatus) at Tippecanoe River State Park posed to give me a better photo than I have taken in past encounters with the species.
I continue to be impressed by ovipositor lengths in female straight-lanced meadow katydids (Conocephalus strictus) like this one at the Winamac Fish & Wildlife Area.

Looking ahead to 2023, my top priorities again will be visits to new sites, and efforts to conclude searches for species in counties where I have yet to find them but where they are likely to occur.

Dusky-faced Year

by Carl Strang

My study of singing insects in the Chicago region is mainly distributional, as I map out the locations where I find the 100+ species of singing crickets, katydids, grasshoppers and cicadas. There are some overarching themes, however. I am interested in the several species that have expanded their ranges northward, and are continuing to do so. The landscape ecology of these insects provides many illustrations of that relatively new field’s power. One of the most important findings, however, is the identification of species that are so uncommon as to be in possible danger of regional extinction. I pointed to one of these, the stripe-faced meadow katydid (Orchelimum concinnum), in the previous post.

For most of the years of this study I had a similar concern over the dusky-faced meadow katydid (O. campestre), a close relative of the stripe-faced. This year’s results have relaxed that worry, as I have found the species in six more places.

Female dusky-faced meadow katydid at Romeoville Prairie Nature Preserve, Will County, Illinois
Male dusky-faced meadow katydid at Seidner Dune and Swale Nature Preserve, Lake County, Indiana

Two of these newly found populations, at Seidner and in the Newton County portion of Indiana’s LaSalle Fish and Wildlife Area, are among the largest I have encountered. I only surveyed part of the expansive Romeoville site, and there is a large wetland in LaPorte County’s Kingsbury Fish and Wildlife Area, which also may harbor big populations.

Map of the Chicago region, showing sites where I have found dusky-faced meadow katydids. Open circles represent counties where the species was known historically, but where I have not yet found it.

Though the species appears to be safe in the region for now, they only occur where native wetland grasses have not been displaced by invasive species such as common reeds, hybrid cattails and reed canary grass. Their fate is in the hands of people managing their wetland homes.

Seeking Stripe-faced

by Carl Strang

Last year in early August I stumbled across a population of stripe-faced meadow katydids (Orchelimum concinnum) in a dolomite prairie wetland in the Des Plaines Conservation Area of southern Will County, Illinois. This was a significant discovery, because otherwise the only place I had found the species in my 22-county study region was at Illinois Beach State Park. When I went back later in the season to assess the population, I found they were done, the shallow soil above the dolomite bedrock apparently having dried out from under them.

This year I went back to that site in late July, and found many more stripe-faced males singing than I had observed a year ago. A 1962 paper by Thomas and Alexander associated the species with alkaline soil conditions, so it was reasonable to seek them in other dolomite wetlands. I drove up to the Lockport Prairie preserve in central western Will County, and was pleased to find a significant population there as well.

Stripe-faced meadow katydid at Lockport Prairie

That site had other interesting and relatively uncommon species, too.

Clipped-wing grasshopper (Metaleptea brevicornis) at Lockport Prairie

I knew of two other dolomite-influenced sites I could check, and did so on the last day of July. At both the Lemont Quarries of southwest Cook County and in southern DuPage County at Waterfall Glen Forest Preserve I did not find stripe-faced meadow katydids but did find a close relative, the dusky-faced meadow katydid (Orchelimum campestre), which apparently replaces the stripe-faced species there. The DuPage observation is a county record for recent times, however, so a valuable find nonetheless.

Little Grass Cicada

by Carl Strang

One of my early-season goals this year was to see if there are any little grass cicadas (with the delightful scientific name of Cicadettana calliope) in my study region. They are known from several Illinois locations, and last year I found that they persist in the Loda Cemetery Prairie Nature Preserve in southern Iroquois County. That was a less than satisfactory experience, though. I could hear them singing through the SongFinder pitch-reducing device, but their little buzzes were too high for me to hear unaided. In two hours’ effort I never saw one.

I went earlier this year, on July 9, and there were many more singing. So many, in fact, that my other, newer pitch-lowering device, a Walkabout bat detector, didn’t allow me to zero in on one. Those greater numbers increased my chances, though, and during my visit I saw several. They were quick to fly away, so it took an hour for me to get photos of a couple of them.

Dorsal view of a little grass cicada on a rattlesnake master stem
Lateral view of another, on the edge of a leaf

These guys are teeny-tiny, body length half an inch, wings bringing it out to ¾ inch. Their song perches are low in the vegetation, so buried that they are harder to see later in the season when the plants are growing thickly. The songs are distinctive, series of short buzzes that each rise in pitch at the end. I was sure I never had encountered them in prairies in my region, but there still was one to check. I drove up to the Mskoda Nature Preserve in Kankakee County, a Nature Conservancy property, and walked through the prairie at its south edge. There were no prairie-dwelling cicadas to be heard.

A DuPage County Record

by Carl Strang

I have been studying singing insects for more than 15 years, now, so I seldom find a new species in my home county of DuPage in Illinois. I paid a visit to the West Chicago Prairie Forest Preserve on the July 4th weekend to assess the population of prairie cicadas (Okanagana balli). I was pleased to get a higher than usual count of 13 singing males on my survey route, and was heading out when I heard the zuzz-zuzz-zuzz of a stridulating grasshopper.

Members of the stridulating slant-faced grasshopper subfamily don’t sing very often, so I want to pursue them whenever I hear one. I figured that it would prove to be a marsh meadow grasshopper (Chorthippus curtipennis), which I had found on that preserve a couple of years previous, but the plot thickened when I found that the singer was in a clump of low brush, an unlikely spot for Chorthippus. I moved slowly, taking a single step between the bouts of song. I was close to the source when up hopped the singer.

It was a sprinkled grasshopper (Chloealtis conspersa)

Previously I had found these mainly in areas with sand soils, so a county record on DuPage’s clay soils opened the door to new possibilities.

Howard County Bioblitz

by Carl Strang

Howard County, the Indiana county that has Kokomo as its seat, hosted a bioblitz in late June. Though still early for singing insects, it provided the opportunity to fill in distributional information for a couple species of interest. I had heard some northern wood crickets (Gryllus vernalis) singing at the Beanblossom Bottoms bioblitz at the beginning of the month, but I did not find them in Howard County. If they had been there historically, the reduction of the county’s forests for agriculture left them with too little habitat to persist.

A northern wood cricket from Eagle Creek Park, Indianapolis, the farthest north I have found the species in Indiana.

Spring trigs (Anaxipha vernalis) are abundant in southern Indiana (see the previous post for photos). They barely make it to the 10 northwestern counties of my study region. In Howard County they were present in scattered, though reasonably large, colonies.

Otherwise, the few singing species I found were common and expected.

Carolina grasshopper (Dissosteira carolina)
Roesel’s katydid (Roeseliana roeselii)
Conehead katydid nymph, possibly a Nebraska conehead (Neoconocephalus nebrascensis)

As usual, I photographed a few other species met along the way.

Eastern forktail (Ischnura verticalis)
Common whitetail (Plathemis lydia)

Also as usual, I set up a sheet with a UV light to see what moths and other species would appear in the evening.

A camel cricket, subfamily Ceuthophilinae, a non-singing species
A mantidfly (Leptomantispa pulchella)
The moth that I thought most interesting was this Canadian petrophila (Petrophila canadensis). The aquatic caterpillars live in stream riffles, sheltering themselves in silk shelters attached to rocks and eating diatoms and algae.
Ailanthus webworm (Atteva aurea)
Horned spanworm (Nematocampa resistaria)
Yellow-shouldered slug moth (Lithacodes fasciola)
Three-spotted fillip (Heterophleps triguttaria). The third spot on each wing is a tiny one near the tip.
Large maple spanworm (Prochoerodes lineola)
This could be either a banded tussock moth (Halysidota tessellaris) or a sycamore tussock moth (H. harrisii).
Exhausted brocade (Neoligia exhausta). It didn’t look any more tired than the others.
Common gray (Anavitrinella pampinaria)
Common idia (Idia aemula). This one took the longest to identify. Though I am familiar with the species, they usually are much darker than this.

As you can see from these past two blogs, forest moths are diverse and beautiful.

Beanblossom Bottoms Bioblitz

by Carl Strang

Each year an early highlight of the field season is the bioblitz series sponsored by the Indiana Academy of Science. This year’s event focused on the Beanblossom Bottoms Nature Preserve, near Bloomington. In a bioblitz, field biologists gather to see how many species of organisms they can find in some designated area over a weekend.

Bioblitz field headquarters

These events traditionally are held in June, which is too early for most of the singing insects I study. There always is something to learn, however. For instance, spring trigs (Anaxipha vernalis) barely make it into my 22-county study area, which includes ten counties in northwest Indiana. I improve my understanding of this tiny cricket when the bioblitzes are sited farther south.

A spring trig from Beanblossom Bottoms
Male spring trigs usually have dark brown heads

There are a few other early species I expect to find each year, including the green-striped grasshopper (Chortophaga viridifasciata).

Green-striped grasshopper males usually are brown. It’s the females that are green.

I also watch for other interesting species I may encounter along the way.

Little wood-satyr, Megisto cymela

Otherwise, I put up a sheet with an ultraviolet light in the evening. Moths are my focus then, as they (particularly in the caterpillar stage) are ecologically important, and we seldom get a moth specialist on these bioblitzes. Other interesting insects show up, too. Here are some of the ones that were drawn to the light at Beanblossom Bottoms.

This is a glowworm (Phengodes sp.). I turned this one over to the group from Purdue University. They study beetles, and this is an uncommon one, though it may not look like a beetle.
A couple spring fishflies (Chauliodes rastricornis), one of each gender, came to my sheet.
Grape leaffolder (Desmia funeralis)
LeConte’s haploa (Haploa lecontei), a tiger moth
Pink-barred pseudeustrotia (Pseudeustrotia carneola)
Large lace-border (Scopula limboundata)
Discolored renia (Renia discoloralis), a consumer of dead leaves when a caterpillar
Deep yellow euchlaena (Euchlaena amoenaria)
Large mossy glyph (Protodeltote muscosula)

This was not the only bioblitz in June. I’ll post on the other one next time.

Updated Singing Insects Guide

by Carl Strang

I recently sent out my updated guide to the singing insects of the Chicago region. Newly added glossary and index sections bring it to 138 pages. If you already are on the mailing list, you should have received it. If you want to be added (it’s free, a 5-odd mb pdf document), simply email a request to me at wildlifer@aol.com.

Drinking-Age Cicadas?

by Carl Strang

Every few years I read back through all the accumulated field notes from my singing insect study, which began in 2006. What this mainly accomplishes is to reveal early errors that later experience allows me to correct. This time, though, I found a gem as I read the 2011 notes.

In the late spring and early summer of that year I was puzzled by the appearance of unusual numbers of periodical cicadas. It wasn’t just me, as the notes include reports from others in northeastern Illinois.

Cassin’s 17-year cicada, Magicicada cassinii

This was not a major emergence. I noted a total of 16 cicadas that I heard that year, but there had been none the previous two years. In 2008 I heard 43 cicadas, but those were what I call “oops cicadas,” individuals that came out a year after the 2007 major emergence of Brood XIII 17-year cicadas. Back then I was inspired to write a song about them (a polka seemed appropriate):

In 2011 I was puzzled by this upward blip in cicada numbers. Now, however, I can take advantage of recent findings to offer a possible explanation.

Researchers who specialize in studying these creatures have found that they “decide” to emerge a year in advance. This is indicated by a change in nymph eye color in the 16th year for 17-year cicadas and the 12th year for the 13-year cicadas that occur in the South.

The second relevant finding is that sometimes a few 13-year cicadas come out when they are 9 years old. Together, these observations imply that the cicadas count years in groups of four. If that is true, then the 9-year cicadas decide to emerge after two 4-year counts. Three 4-year counts lead to 13-year cicadas, and four 4-year counts result in 17-year cicadas.

This brings me back to the periodical cicadas that appeared in 2011, four years after the major emergence of 17-year cicadas in 2007. Could it be that these were 21 years old? If so, they were drinking age.

t-shirt design

Even those might not be the oldest, however. I heard a single periodical cicada in 2012, who might have been a 22-year-old oops cicada. The count was back to zero in 2013.

Tinklers

by Carl Strang

After last year’s field season was done, I learned of the possibility that slow-tinkling trigs (Anaxipha tinnulenta) might be in my study region. Checking this needed to be a high priority this year, because the tink-tink-tink song of this newly described little cricket is very similar to that of the tinkling ground cricket (Allonemobius tinnulus). In fact, I had assumed that all the tinkling songs I had been hearing across the region were from the ground cricket. I sent two of my recordings from past years to Wil Hershberger, the experienced sound recordist, and he gave reason to think that these both were of slow-tinkling trigs rather than tinkling ground crickets, as I had assumed.

I began this year’s quest at Big Marsh, a Chicago Park District site where I heard tinkling songs last year. I began finding the songs, coming from dense, tall vegetation. I saw some trigs in that first spot, and did not see tinkling ground crickets, but that was not decisive because I also could hear the songs of another species, Say’s trig (Anaxipha exigua), in the same spot. The 2014 paper by Tom Walker and David Funk which described the slow-tinkling trig indicated that its general appearance is practically identical to that of Say’s trig.

In a second, more open location, there were tinkling songs but no Say’s trigs were singing. I spent a lot of time on the ground trying to spot one of the singers. Clearly they were 2-3 feet above the ground, which practically ruled out tinkling ground crickets, but I needed more. Though I never saw a singing tinkler, I caught a female trig in the same clump of plants. I photographed her before returning her, and she met the one gross anatomical separator from Say’s trig, having a proportionately longer ovipositor:

My next attempt came a few days later. I traveled to Indiana’s Jasper-Pulaski Fish & Wildlife Area. When I checked in at the site’s headquarters, I heard tinkling songs coming from some tall, dense herbaceous vegetation nearby. I made a recording but did not see any suspects:

 I went on to some woodland edges where I have photographed tinkling ground crickets in the past. Immediately it was clear that the tinkling songs there were different from the ones at the headquarters:

They were quieter, though that could have been because the singers were buried in leaf litter. More significantly, they were faster, the tinkling notes coming at a rate of 8 notes per second rather than 6. That may not seem like much, but I noticed it immediately. If anything, the temperature there was a little cooler, so if all else was equal the rate should have been slower rather than faster. There was no question that these were tinkling ground crickets, which I could see near the recorded individuals.

I went to another more open spot with tall dense vegetation where members of the slower tinkling species were singing. I made a recording, then dug in with my net. I caught two female trigs and a male, which I placed in a container to take home. No Say’s trigs were singing there, so I was hopeful. I set the crickets up in a cage, and to my delight that evening the male began to produce his tinkling song. That was the final confirmation I needed.

So far, my analysis of the sound recordings indicates that tinkling ground crickets have a faster note rate than slow-tinkling trigs at similar temperatures. The pitches (carrier frequencies) of the songs are so similar that these cannot be used to separate the species. There is another difference, however, that Wil pointed out and I can confirm. When the notes are magnified in a sonograph, those of the two species usually have different shapes. First, the slow-tinkling trig:

The largest, brightest notes are those of the trig. The shape is generally horizontal, in this case with symmetrical downward tails at each end. Sometimes the shape is a gentle, nearly flat arc with no tails. Sometimes, however, there is a lower descending tail on the right end. Now, the tinkling ground cricket:

Here there is practically no horizontal portion, the shape angling down and to the right. Sometimes the shape is sharply arched, but the right end almost always shows a longer downward tail. If you look again at the trig’s sonograph, you can see a line of smaller, more rapid notes just above those of the trig. There was an Allard’s ground cricket (Allonemobius allardi), a close relative of the tinkling ground cricket, close enough to be picked up by the microphone. Allard’s has an even more rapid note production than the tinkling ground cricket, but you can see that it shares the note shape of a downward right-hand tail.

Since those initial experiences, I have made a few dozen recordings of tinkling songs in several counties. Often note shape alone is distinctive enough to ensure an identification, but some are ambiguous enough to give me pause. I found that I need to standardize the notes, expanding them so they are 0.2 inches long on the computer screen. All of the songs coming from leaf litter on the ground have been those of tinkling ground crickets, and all of those a foot or more above the ground have been those of slow-tinkling trigs. Tall dense vegetation always has proven to house the trigs. Finally, trig songs are produced at a rate slower than ground cricket songs. All but one of the 18 ground cricket songs had note rates of 8 per second or higher. All but one of the trig songs were at 7.5 per second or lower, and 40 of the 46 were below 7. These all were recordings made at relatively warm temperatures, and higher temperatures were associated with higher song rates. At a few sites where both species were present, the difference was clear.

So in the upcoming annual revision of my guide to the singing insects of the Chicago region I will be adding a page for the slow-tinkling trig, and the site maps of these two species will show only locations for each that I have been able to verify visually or through sound recording analysis. The trigs have proven to be more widespread, and I suspect that in DuPage County, at least, they are increasing.

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