DuPage Robust Coneheads

by Carl Strang

Last year, while conducting an evening survey drive to map fall field cricket distributions in my home county of DuPage in Illinois, I was passing through Springbrook Prairie Forest Preserve when I thought I heard a couple robust coneheads singing.

Male robust conehead in singing posture, Newton County, Indiana

Male robust conehead in singing posture, Newton County, Indiana

This was surprising, and I wasn’t able to follow up in 2012, but it was on this year’s research checklist, and on Monday evening I heard them again in the same location. I found a place to park, and to make a long story short was able to confirm my suspicion (a later sonograph analysis of the recording I made will determine whether this was a robust conehead or, less likely given the loudness of the song, a false robust conehead).

This discovery was surprising because in general I have been finding them, as researchers in past decades also have noted, mainly in areas with sandy soils.  No such soils exist outside children’s playgrounds in DuPage. On the other hand, no lesser a light than Richard Alexander listed DuPage County as a place where he had found the species a few decades ago. This is not a simple matter of latitude, as robust coneheads are abundant in sandy Lake County, Illinois, to the north. This species joins the tinkling ground cricket and spring trig as species that I have found in the county, but only in extremely small numbers in one or two places. DuPage County, out of all the 22 counties in my regional survey, is the one I have surveyed most thoroughly, and for nearly 8 full seasons. These few locally rare species are indicators that there probably will be holes in my distributional records for all counties, and so these will need to be judged accordingly. I will need to continue searching for new sites through the seasons and years, as long as I am able to do so.

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Low Hanging Fruit

by Carl Strang

There haven’t been many new posts in this blog recently because mainly I am going after the low hanging fruit. In other words, most of my research time has been going into checking new counties and new sites, as well as return visits to sites visited earlier in the season, to build my database of singing insect species locations. Though this is productive work, most of that product consists of added locations for common species. That’s not exactly fodder for blogging. A few interesting points have come out, however.

Last week I was working in Indiana. The weather was unseasonably cool, but there was plenty of singing action. In Fulton County I heard a broad-winged bush katydid singing, which establishes that northern species down to the southern edge of the survey region. Clearly they are fewer there than farther north, however. As I drove the rural roads in temperatures that were dropping rapidly to the mid-50’s F, I started hearing a strange, unfamiliar song coming from wetter locations. It was a kind of slow, fluttering buzz, reminiscent of the protean shieldback but much louder, and the buzzes were in repeated short bursts. I pulled off at one such location, and soon realized that these were slightly musical coneheads, their songs altered by the cold, but still singing in lockstep unison. I also found that species in Pulaski County, so they are widely dispersed at least in the northwest Indiana counties.

Slightly musical conehead

Slightly musical conehead

On the way back home I explored some sites in Lake County, Indiana. The best of these was the Hoosier Prairie Nature Preserve. This is a relatively large, high quality prairie and savanna property. Broad-winged bush katydids were abundant there.

A portion of the Hoosier Prairie Nature Preserve

A portion of the Hoosier Prairie Nature Preserve

On the way to Hoosier Prairie I passed a sign with a familiar name.

Tom Sporre Wildlife Area

Tom Sporre Wildlife Area

Tom Sporre was in the Purdue wildlife undergraduate program a year ahead of me. Personable and proficient, he went on to become a prominent Indiana waterfowl biologist who died much too young. I was pleased to see a marsh and prairie set aside under his name.

Kankakee County

by Carl Strang

The traveling singing insect survey took me to Kankakee County one day recently. It proved to be primarily an agricultural county, and I spent much of the day finding places to which I will not need to return. The county’s gem is Kankakee River State Park, and all the singing insects I had found elsewhere in the county also were there, a total of 15 species.

An attractive scene at Kankakee River State Park.

An attractive scene at Kankakee River State Park.

These included the first robust conehead and northern dusk-singing cicadas of the year. My past experience with that cicada was occasional songs during the day, from late morning through dusk, but those in the state park lived up to their name. None sang until about 15 minutes before sunset, but then many were singing. The robust conehead was a through-the-car-window identification. It was singing in an upland meadow, and there was no place to pull off. The only other possibility for that loud droning song after dark is the false robust conehead, but until I have confirmed the presence of the latter this far north I am inclined to go with robustus. At some point I will make a series of recordings to see if I can discover the more southern of these two sibling species in our area.

Seeking the Lyric Cicada

by Carl Strang

Last Thursday I searched for the northernmost lyric cicadas, having found them superabundant in Kendall County and absent in the portions of McHenry County I surveyed. This is a woodland species that seems especially common in bottomland forests, so I took advantage of our glacial legacy and followed rivers north and south (rivers developed in low zones between the concentric end moraines), but also stopped at other woodlands along the way.

Lyric cicada, Tibicen lyricen

Lyric cicada, Tibicen lyricen

There clearly is a gradient in density from south to north. In Kendall County, and along the Des Plaines River at the south edge of DuPage County, large numbers of lyric cicadas form loud choruses. In central DuPage County, at locations such as Fullersburg Woods and Mayslake, this is a regular part of the insect fauna, but they are down to countable numbers of individuals.

The clearest indication came as I followed the West Branch of the DuPage River, and continued north beyond it.  At Blackwell Forest Preserve, in west central DuPage County, there was a ratio of 11 lyric cicadas to 18 or so Linne’s cicadas (= 0.61; Linne’s has a fairly uniform density through the area). At Elsen’s Hill, a few miles farther north, the ratio was 4:7 (0.57).  Several miles farther north, at West Branch Forest Preserve, the ratio was 3:7 (0.43). The farthest north I found this species was at Shoe Factory Woods, in north Cook County, where the ratio was 2:12 (0.17).

Shoe Factory Woods has some good prairie and savanna restorations going.

Shoe Factory Woods has some good prairie and savanna restorations going.

By that point, though, cicadas had entered their afternoon lull, and I wasn’t hearing many of any species. Shifting west and driving south along the Fox River, I heard the next lyric cicada at the north edge of St. Charles, a point close in latitude to West Branch Forest Preserve. For now I have a sense of what is happening in the northern edge of this species’ range, but I will continue to monitor them for changes, and to continue seeking that northernmost population in the region.

Mayslake Update

by Carl Strang

Between trips to Indiana for parental care, and vacation days for research, I haven’t spent as much time as usual in Mayslake Forest Preserve. Life goes on there, of course, and I have some glimpses to share.

This summer’s deer have been more secretive than usual. This doe, photographed at the beginning of July, showed no signs of nursing.

This summer’s deer have been more secretive than usual. This doe, photographed at the beginning of July, showed no signs of nursing.

However, she sometimes has accompanied another doe, and this week I saw tracks of a fawn, which I expect to encounter at some point.

There have been a few tawny edged skippers this year, a species I have seen at Mayslake before but not in most years.

There have been a few tawny edged skippers this year, a species I have seen at Mayslake before but not in most years.

A new species for the preserve list was Mydas tibialis, a large and impressive, flower-visiting fly discovered at Mayslake by Nikki Dahlin.

A new species for the preserve list was Mydas tibialis, a large and impressive, flower-visiting fly discovered at Mayslake by Nikki Dahlin.

The rains of spring and early summer, along with the prairie burns, have resulted in Mayslake’s prairies blooming with unprecedented beauty.

The first swamp rose mallow I have seen blooming on the preserve.

The first swamp rose mallow I have seen blooming on the preserve.

Prairie blazing stars are just now peaking.

Prairie blazing stars are just now peaking.

Banks of yellow coneflowers and wild bergamot are providing gorgeous backdrops.

Banks of yellow coneflowers and wild bergamot are providing gorgeous backdrops.

McHenry County Singing Insects

by Carl Strang

On Saturday I traveled north to McHenry County, Illinois, to continue my regional survey of singing insects. That county is blessed with some impressive sites, and I was able to cover only parts of two of them. Moraine Hills State Park has a wide range of representative habitats covering large acreages.

Wetlands in particular dominate the landscape.

Wetlands in particular dominate the landscape.

Much of the park is spanned by a network of bike paths, and my next survey trip there will involve my bike. I also paid a visit to a McHenry County Conservation District property, Glacial Park.

When I think of Glacial Park I think of glorious vistas.

When I think of Glacial Park I think of glorious vistas.

There are savannas, restored prairie, and wetlands of varied quality.

This marsh looks very good, at least around the edges.

This marsh looks very good, at least around the edges.

The bog so far is holding its own against a fringing ring of reed canary grass.

The bog so far is holding its own against a fringing ring of reed canary grass.

The bog is rich in sphagnum moss, but was quiet on Saturday, so I hope to find sphagnum ground crickets singing when I return in a month or so.

The bog is rich in sphagnum moss, but was quiet on Saturday, so I hope to find sphagnum ground crickets singing when I return in a month or so.

The species count for McHenry County totaled 16, the list mainly overlapping that for Kendall County from the previous day. The differences were interesting, though. Where the day at Kendall was dominated by omnipresent choruses of lyric cicadas, I did not hear a single member of that species in McHenry. At some point I will follow a couple rivers north and south to find the current range limit for that species, which is common in DuPage County not far south of McHenry.

The McHenry woodlands had rattler round-wing katydids, which I did not find in Kendall County, but the latter had Nebraska coneheads which I did not find in McHenry County. I need to find a drier, more open woodland in Kendall County, but the Nebraska conehead likely is a species which, like the lyric cicada, has its northern range limit somewhere between those two counties.

Kendall County Singing Insects

by Carl Strang

On Friday I took a vacation day to begin surveying singing insects in Kendall County, Illinois, just southeast of my home county of DuPage. It was a good, productive day, yielding a total species count of 19.  There are some high quality wet to mesic forests and restored prairies in the four sites I visited.

The best quality forest was in Richard Young Forest Preserve. There were few invasive plants in this sugar maple forest, which was cut by a nice stream or two and had a beautiful little kame named “Hepatica Hill.”

The best quality forest was in Richard Young Forest Preserve. There were few invasive plants in this sugar maple forest, which was cut by a nice stream or two and had a beautiful little kame named “Hepatica Hill.”

Harris and Hoover Forest Preserves show promise for future visits, though I did not pick up many species there on this trip. The most extensive area was Silver Springs Fish and Wildlife Area (formerly Silver Springs State Park).

Silver Springs has good bottomland forest along the Fox River, and a wide range of open lands. This meadow had many prairie grasses mixed in.

Silver Springs has good bottomland forest along the Fox River, and a wide range of open lands. This meadow had many prairie grasses mixed in.

This restored prairie was one of my favorite locations, yielding several singing insect species.

This restored prairie was one of my favorite locations, yielding several singing insect species.

I did not find much in the way of marshland, and no dry oak woodlands or savannas. I will need to see if Kendall County has good examples of such habitats. As for singing insects, highlights included good numbers of broad-winged bush katydids and a couple dog day cicadas, two of the species I am following for southern range boundaries. The dominant singer was the lyric cicada, with loud choruses providing a continuous background through the day.

This gladiator meadow katydid gave me a photo opportunity. Though the reflections from the flash reduce the quality of this as an image, they do a nice job of highlighting the relatively straight rear boundary of the pronotum, helpful in distinguishing this species from the common meadow katydid.

This gladiator meadow katydid gave me a photo opportunity. Though the reflections from the flash reduce the quality of this as an image, they do a nice job of highlighting the relatively straight rear boundary of the pronotum, helpful in distinguishing this species from the common meadow katydid.

The one species that I heard for the first time this year was the Nebraska conehead.

Many Nebraska coneheads were singing along River Road in the north part of Silver Springs and in residential properties adjacent to it. This one agreeably posed.

Many Nebraska coneheads were singing along River Road in the north part of Silver Springs and in residential properties adjacent to it. This one agreeably posed.

I hope to get back to Kendall County at least one more time this year.

Toward Standardized Language

by Carl Strang

We have no standardized language to describe singing insect sounds. Such is needed, because different people use different words to describe the same song. We’re not lacking for words, in a sense we have too many.

The oblong-winged katydid’s song has been described in several different ways, for instance.

The oblong-winged katydid’s song has been described in several different ways, for instance.

Richard Alexander was the dean of singing insect research in the Great Lakes area before he retired from his post at the University of Michigan. Here are some of the words and phrases he used: “clear, whistle-like sound (crickets) or a ‘noise’ (buzz, click, rasp, whirr, rattle, etc.) (all groups except crickets).” Buzz, crackling, noise, rasping, lisp, “tick-buzz,” “whispery, intense buzzes,” sibilant buzz, smooth without vibrato, vibrato, whining buzz, rough buzz, trill, chirp, “tink” sound, phrase, ragged phrase, “zzzzzz-zik-zik”, seedy.

More recently, Elliott and Hershberger in their popular book on singing insects used a lot of quantitative language regarding frequency (pitch, the highness or lowness of sound), but also a lot of terms that remain undefined as far as I can see: chirp (“each chirp is actually a brief trill”), buzz, buzzy trill, note, “chirps (brief buzzes),” tick, “clicks or tsips,”, purr, clicking whirr, raspy notes, clicks or zits, shuffle, rattling, zeee-dik!, dzt!, lispy buzzing notes, swishing rattles, pulsating drone, whining drone.

In approaching this problem I like Alexander’s division of songs into two main categories, tones on the one hand (relatively clear, musical notes like those of a wind or stringed instrument, for instance a flute or a single violin note; such a sound has a very narrow frequency range) and more mechanical sounds on the other (resembling the sounds produced by percussion instruments such as rattles, drums, scrapers, clickers, or else a ticking watch; a wide range of frequencies is produced at once, so there is no single, clearly dominant tone).

Words connected to tones include: musical, chirp, trill, “tink,” note, whine, siren. Words connected to mechanical sounds include buzz, tick, click, rasp, whirr, rattle, noise, crackle, lisp, swish, and a variety of attempts to render the sounds into words (zick, zit, dzt, zee, dik, tsip, zzz). I am not sure what to do with “drone.” It usually is applied to cicada songs, some of which are more tone-like (canicularis) and some of which are more mechanical (linnei). Perhaps a drone is a third, somewhat intermediate category, with pulses that are too rapid to distinguish but each of which has a broad frequency range (I am not speaking of vibrato here, but the individual vibrations that make up the droning sound). The song of Roesel’s katydid qualifies as a drone, under this definition.

For the moment, I think there are six primary terms needed in describing insect songs. Each of these can be further qualified with descriptors.

A note is a separate, musical tone that can be very short (Allard’s or tinkling ground cricket), or long and continuous (four-spotted or black-horned tree cricket). Descriptors can specify the pitch, length, volume and tonal quality of the sound. Sonograph analysis reveals that a note is composed of pulses, but these usually are too rapid to be discerned by ear (though some of those tree cricket songs acquire a wavering quality at low temperatures).

A trill is a rapidly and evenly pulsing sound (the pulses slow enough to be discerned) that has a tone quality. The pulses seem connected, rather than having pauses, however brief, between them. A trill can be brief (jumping bush cricket) or extended (Say’s trig). A trill can be qualified in the same way as a note, with the addition of pulse rapidity, and pauses or interruptions that occur in some species.

A chirp is a brief bundle of rapid, irregular notes (spring and fall field crickets produce the most familiar example). Irregularity in the spacing, volume and/or length of the element notes separates a chirp from a trill. Chirps tend to be relatively brief.

A drone is the mechanical analog of a note, but I can think of no brief examples (the striped ground cricket and two-spotted tree cricket are possibilities, though I am more inclined to think of these as buzzes). The pulses or vibrations are too rapid to discern, though there may be vibrato. Examples include extended cicada songs like those of the dog day or Linne’s cicada, Carolina ground cricket, and Roesel’s katydid. Descriptors include volume, length, nature and abruptness of beginnings and endings, vibrato (which can be more legato or more staccato in its attack), pitch range, whether there is a rise and fall in pitch, and tonal quality.

A buzz is the mechanical analog of a trill, and like a trill its length can be short (the elements of a common true katydid song), intermediate (as in most meadow katydids) or extended (as in the rattler round-winged katydid). Here the descriptors include volume, length, abruptness of beginnings and endings, pitch range or center, pulse rate, and sound quality (e.g., rasping, lisping, rattling).

A tick is the briefest of mechanical sounds. Examples are found in the typical song of the greater angle-wing, and the series of brief sounds leading into the buzz of many meadow katydids. Volume, number, and, when they are produced in series, descriptions of the spacing and rapidity of ticks, help describe them.

A perfect system may not be possible. Not only do we have an excess of vocabulary, we also know that different people hear the same song differently, and so will use different words to describe it. I would greatly appreciate help with this, so please comment on what needs clarification or to express points of disagreement.

Return to Newton and Jasper

by Carl Strang

On Monday I returned to Newton and Jasper Counties, Indiana, to survey for singing insects that had emerged since my earlier visits there (Newton County was the site of the bioblitz last year; I went to a new site this time, the Willow Slough State Fish and Wildlife Area). In Jasper County I went back to the Jasper-Pulaski Fish and Wildlife Area, and was especially interested in revisiting the savanna and sand prairie.

The savanna-sand prairie site at the time of my first visit.

The savanna-sand prairie site at the time of my first visit.

The most exciting find was an unfamiliar insect singing loudly from the black oak woodlands of both sites in the early to mid-afternoon. Its song was a series of quick buzzing sounds, as though a sword-bearing conehead (which sings at night) woke up way early and got hold of a megaphone. With that volume at that time of day well up in the trees it had to be a cicada, and when I later referred to sources and listened to reference recordings it was clearly the green-winged cicada, Diceroprocta vitripennis. This is a species I thought I might have heard in DuPage County at the time of the periodical cicada emergence in 2007, but the songs were difficult to separate from the loud Magicicada choruses, and I have not heard it since, until Monday. I did not see one, but hope to get a photo in the future.

Otherwise the singing insects were familiar, though I did pick up a number of county records and heard a few species singing for the first time this year.

Also, a very large, interesting looking grasshopper flew up from the sand prairie and landed on a tree after a graceful flight on its long wings.

It was noticeably larger than the Carolina grasshopper, the most common large grasshopper in the region.

It was noticeably larger than the Carolina grasshopper, the most common large grasshopper in the region.

The color pattern, behavior and habitat point to the obscure bird grasshopper (Schistocerca obscura), not a singing insect but an interesting attention-grabber nevertheless.

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