Less Confused

by Carl Strang

An emerging theme of my field season this year is defining range boundaries of the singing insects I am studying. When there is a boundary within my 22-county study area, usually the population density thins out toward the edge. That has me looking critically at some of my past observations. A case in point is the confused ground cricket (Eunemobius confusus).

Confused ground cricket. These are little guys, a quarter of an inch long.

Looking at past records, I found that only two were north of the midpoints of Kane, DuPage and Cook Counties in Illinois. There was a single individual in the Lyons Prairie and Marsh area, legally within Lake County, Illinois, though managed by the McHenry County Conservation District. I had noted a small group of the crickets in the New Munster Wildlife Area in Kenosha County, Wisconsin. Now several years on without other records for those counties, I felt the need for a double check. I visited both sites and found no confused ground crickets. I did, however, hear other singing insects that I now believe fooled me.

Here is a recording of a confused ground cricket. This guy was singing in cool temperatures, and so was slowed somewhat:

Usually the song would be faster, with trills or chirps about a second long, alternating with equal-duration spaces within which the cricket produces stuttering sounds. The Lake County and Kenosha County observations both were made well into long days in the field, and my fatigue along with relative inexperience years ago, led me to mistakes. I now believe that the Lake County observation in fact was a Say’s trig, producing an uncommon alternative song composed of brief trills with the same timing as a confused ground cricket. Here is an example of that song:

You may notice there are occasional stutters between the trills. On my return visit to the New Munster site, I did not hear any confused ground crickets, but I noticed that there were a lot of black-legged meadow katydids singing in dry habitats, unusual and unexpected in that species. Furthermore, in the heat they were singing so fast that their buzzes were about a second long, with the ticks compressed in such a way that they resembled a confused ground cricket’s stutters. Here is a black-leg recording with similar timing:

These conclusions support my practice of making lists of the species I hear on each visit to each site. That makes the oddities stand out, helping me to correct errors like the ones I have described here. I now can close the book on confused ground crickets, with the final map:

Black dots indicate counties where I have found confused ground crickets. The red stars mark locations of the northernmost observations within Kane, DuPage, Cook and Berrien Counties.

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Wil’s White Box

by Carl Strang

The leading popular singing insects web page is The Songs of Insects, created by Wil Hershberger and Lang Elliott. Lisa Rainsong and Wendy Partridge of Cleveland, who study northern Ohio’s singing insects much the same as I do for the Chicago region, are friends of Wil’s, and we planned a week together here to help further Wil’s expansion of the Songs of Insects project. We succeeded in finding a number of new species which ultimately will be added to that website. Along the way Wil showed us a white box, the portable version he invented to get amazing photos.

Here Lisa tries out the setup as a rightly proud Wil coaches.

Here Lisa tries out the setup as a rightly proud Wil coaches.

I got to try it, too.

This was my best shot of a confused ground cricket. Wil’s more elaborate home setup allows him to get even better exposures.

This was my best shot of a confused ground cricket. Wil’s experience allows him to get even better exposures.

My try with a marsh conehead was even more satisfactory.

My try with a marsh conehead was even more satisfactory.

As an ecologist, I philosophically prefer field shots of the insects in habitat, but I am tempted to create a white box of my own. The device certainly highlights the structure and colors of these creatures. Wil published the plans on line.

Ecoblitz Continued

by Carl Strang

The Indiana Forest Alliance, a non-profit conservation organization, has been sponsoring a species survey in portions of two state forests in southern Indiana. As it consists of repeated weekend sessions over a period of years, they are calling it an “ecoblitz” rather than a bioblitz, which is a one-time event limited to a 24- or 48-hour time span. I went down for a weekend last fall, and returned in early August to complete the singing insects portion of the survey.

The area is forested, except for some small areas of tall, dense herbaceous growth in stream bottoms. The singing insect fauna consequently is mainly of forest species.

Confused ground crickets were common on the forest floor.

Confused ground crickets were common on the forest floor.

Say’s trigs by the hundreds sang in the open herbaceous areas.

Say’s trigs by the hundreds sang in the open herbaceous areas.

Widely scattered small groups of rattler round-winged katydids could be heard at night.

Widely scattered small groups of rattler round-winged katydids could be heard at night.

This nymph is recognizable as a male fork-tailed bush katydid by the distinctive appendages at the tip of his abdomen.

This nymph is recognizable as a male fork-tailed bush katydid by the distinctive appendages at the tip of his abdomen.

Some of the other species that sang for us were swamp cicadas, Nebraska coneheads, lesser angle-wing katydids, jumping bush crickets and common true katydids.

I also helped with photography at a night-time moth survey at illuminated sheets.

This small-eyed sphinx was one of the two hummingbird moths we attracted.

This small-eyed sphinx was one of the two hummingbird moths we attracted.

A blinded sphinx also dropped in.

A blinded sphinx also dropped in.

A grape leaffolder

A grape leaffolder

This lesser grapevine looper appears to be sending out pheromone.

This lesser grapevine looper appears to be sending out pheromone.

A Cope’s gray treefrog hopped in, possibly sensing the smorgasbord we had created.

A Cope’s gray treefrog hopped in, possibly sensing the smorgasbord we had created.

 

Morgan Monroe-Yellowwood Ecoblitz

by Carl Strang

The Indiana Forest Alliance is sponsoring a multi-year species survey of the back country portion of the conjoined Morgan Monroe and Yellowwood State Forests in Monroe and Brown Counties of southern Indiana. They are holding bioblitz weekends at various seasons so as to get a more complete picture than a single bioblitz would produce. Jeff and Mary Stant are providing the principal organizational and logistical support. I paid my first visit on September 12 to begin inventorying the singing insect species.

While waiting my turn to go into the survey area, I checked out the base camp in an old field with scattered young trees adjacent to the riparian edge of a wooded stream. The species mix was much like I would expect to find in a dry area in northern Indiana or Illinois.

Woodland meadow katydids were very common in woodland edges, much more abundant than I have found them farther north.

Woodland meadow katydids were very common in woodland edges, much more abundant than I have found them farther north.

The old field held scattered common meadow katydids.

The old field held scattered common meadow katydids.

Handsome trigs also were common in the riparian edge.

Handsome trigs also were common in the riparian edge.

Allard’s ground crickets were one of several species at the camp.

Allard’s ground crickets were one of several species at the camp.

The forested survey area was, as expected, less diverse, though the cool afternoon temperature probably inhibited some species. The slopes held scattered confused ground crickets, and bottomland herbaceous thickets were full of Say’s trigs, along with good numbers of Carolina ground crickets and more scattered jumping bush crickets and narrow-winged tree crickets.

At one point we flushed out a medium-sized cricket which permitted a quick photo but evaded capture. It was one of the camel crickets, probably in genus Ceuthophilus.

At one point we flushed out a medium-sized cricket which permitted a quick photo but evaded capture. It was one of the camel crickets, probably in genus Ceuthophilus.

We went up to a ridge top in the evening. It was very cold, and few species were managing to sing. There were scattered tinkling ground crickets, Carolina ground crickets, jumping bush crickets, and a few feebly ticking long-spurred meadow katydids. A background hum came from the forest canopy, and occasional individuals could be distinguished to support an identification of Davis’s tree crickets, by far the most abundant singers on that cold night.

I look forward to returning for more ecoblitz weekends next year.

 

Gensburg-Markham Prairie

by Carl Strang

One day last week I drove down to southern Cook County for singing insect survey work. I quickly found confused ground crickets for a county record in the Palos area, then proceeded to the Gensburg-Markham Prairie, which proved so fruitful that it occupied the rest of the afternoon. The dominant sound in that high-quality nature preserve was the buzzing of common meadow katydids.

The name is deceptive. This is one of the few places I have found to date where Orchelimum vulgare indeed is abundant.

The name is deceptive. This is one of the few places I have found to date where Orchelimum vulgare indeed is abundant.

There were other dry-habitat species present as well. I was able to add county records for woodland meadow katydid (my northernmost to date) and for straight-lanced meadow katydid.

This straight-lanced female was content to explore my finger and pose.

This straight-lanced female was content to explore my finger and pose.

The richest portion of the site’s singing insect fauna was the subfamily of stridulating slant-faced grasshoppers. I took lots of photos, thinking I had found the mother lode of species. When I examined them closely, however, the diversity turned out to be mainly within species, and I concluded that most of them in fact were marsh meadow grasshoppers.

Here is a classic adult marsh meadow grasshopper.

Here is a classic adult marsh meadow grasshopper.

But then there were a number of these. After much study I had to conclude that this, too, was an adult marsh meadow grasshopper.

But then there were a number of these. After much study I had to conclude that this, too, was an adult marsh meadow grasshopper.

Ditto for this one.

Ditto for this one.

Even more color variation was provided by nymphs. Again, I think they were marsh meadow grasshoppers.

This one in particular was strikingly colored.

This one in particular was strikingly colored.

And this individual seems aimed toward the pattern of the third adult above.

And this individual seems aimed toward the pattern of the third adult above.

These were my first of the species in Cook County, so they were a happy find. Two other grasshoppers also were my first for the county.

Wetter areas had plenty of short-winged green grasshoppers like this female.

Wetter areas had plenty of short-winged green grasshoppers like this female.

Prize of the day was this critter, the first spotted-wing grasshopper I have seen anywhere.

Prize of the day was this critter, the first spotted-wing grasshopper I have seen anywhere.

She wasn’t giving me good angles for photography, but fortunately I got a clear shot of the dorsal pronotum.

She wasn’t giving me good angles for photography, but fortunately I got a clear shot of the dorsal pronotum.

The inward-curving margins and their posterior big black triangles point to the two local species of Orphulella. There are two cuts in the dorsal surface, which point to O. pelidna rather than its close relative the pasture grasshopper O. speciosa.

This prairie is one I intend to visit in all portions of the singing insect season.

Sound Ideas: 3 Ground Crickets

by Carl Strang

Today I share recordings of 3 ground crickets. The first of these, the melodious ground cricket, is not very well studied, and recordings of its song are not commonly available.

Melodious ground cricket

Melodious ground cricket

The song is a fairly loud, steady trill with a pleasant tone:

That song is most like that of Say’s trig, which can occur in close proximity as both are wetland species. When such is the case, the distinction is clear. Here is a recording of Say’s trig for comparison:

The recordings are a little misleading in that both species can be equally loud. Next up is the sphagnum ground cricket.

Sphagnum ground cricket. This species does not occur away from sphagnum moss.

Sphagnum ground cricket. This species does not occur away from sphagnum moss.

The song is higher pitched and more rapid than that of Say’s trig, which again often co-occurs.

The final species has an interrupted trill, unlike the continuous singing of the previous crickets. The confused ground cricket usually is found in drier portions of woodlands than the more swamp-dwelling melodious ground cricket.

Confused ground cricket

Confused ground cricket

The song is about one second on, one second off. If there are few other sounds, you may hear some stuttering during the “off” intervals:

 

Confused

by Carl Strang

This year there seem to be more confused ground crickets than I have noticed before in DuPage and neighboring counties. Furthermore, their habitat range seems broader. Here is a case in point. A couple weeks ago I was paying the year’s first visit to Midewin National Tallgrass Prairie in Will County. Across one of the interior roads from a grove of trees was a meadow undergoing restoration to prairie, and in that meadow edge a confused ground cricket was singing.

This was the opposite of the species’ typical woodland setting.

This was the opposite of the species’ typical woodland setting.

I moved in closer to see exactly where the cricket was and found, between the bases of the plants, a little pocket of accumulated cottonwood leaves from last year.

This apparently was sufficient microhabitat to suit him.

This apparently was sufficient microhabitat to suit him.

There have been plenty of other instances of meadows with confused ground crickets in DuPage, Will and Kendall Counties. Almost always there are at least scattered trees nearby. The song is distinctive enough that I don’t think it’s a matter of me missing them in the past. Whether this is a 1-year increase, the result perhaps of favorable winter conditions, remains to be seen. This area is close to the northern range boundary for confused ground crickets, so another possibility is that this is evidence of yet another range expansion from the south.

Confused ground cricket

Confused ground cricket

Another sound-location combination that surprised me happened last week. I was driving home from an evening walk at Danada Forest Preserve when I heard what seemed to be a robust conehead, within 2 miles of my home on a road I frequently drive. I turned around, parked, and found it.

Robust conehead from a previous year

Robust conehead from a previous year

It was indeed a robust conehead, practically deafening at close range and with the typical short cone lacking black coloration. A second male sang nearby. These were far from the only DuPage County population I know about. This was, however, in a section of Butterfield Road that was rebuilt in the past few years, and there has been much landscaping in the median and along both edges. It seems almost certain that the eggs from which these coneheads hatched were carried in on nursery material. I’ll be interested in seeing if a new disjunct population builds in that spot.

 

Seeking Northern Limits: Confused Ground Cricket

by Carl Strang

One consequence of this year’s 22-county survey of singing insects is an improved understanding of how some species tail off in density toward the edge of their range. Earlier I highlighted this theme for the lyric cicada and jumping bush cricket. Today begins a series of 3 posts focusing on additional species, beginning with the confused ground cricket.

Confused ground cricket

Confused ground cricket

This is a woodland species, well distributed in the region but with a northern range limit within the 22-county area.

Map indicating the counties in which confused ground crickets are known to occur.

Map indicating the counties in which confused ground crickets are known to occur.

They are spottily distributed throughout the region, but usually in good numbers where they occur, especially toward the south. There are plenty in DuPage County, one of the two northernmost Illinois counties marked on the map. Kenosha County, Wisconsin, is marked because I heard a tiny group of confused ground crickets singing at the New Munster State Wildlife Area. I searched a number of other likely looking spots in that county and the other two Wisconsin counties, without finding this species. It was late enough in the season, though, that I need to make an earlier effort next year, and also to seek them in the other unmarked counties.

Encounters Along the Way

by Carl Strang

As another season of field research into the region’s singing insects winds down, I am starting to look back at the highlights. Some of these were chance encounters that provided new photo opportunities. For example, there was a weakened common true katydid I found on a trail at Waterfall Glen in broad daylight. I didn’t have a good photo of the species, and posed him after removing him from the hazardous trail.

Unfortunately I neglected to place his hind legs in a natural position.

Unfortunately I neglected to place his hind legs in a natural position.

Another species for which I want a better photo is the handsome trig. Some were singing on a cloudy day down in Fulton County, Indiana, and one came out in the open, but the low light resulted in a less than sharp image.

Tiny but colorful, the handsome trig lives in the southern part of the region I am surveying.

Tiny but colorful, the handsome trig lives in the southern part of the region I am surveying.

The Indiana Dunes area provided several photographs.

This oblong-winged katydid female was emitting single clicks in response to the more complex songs of nearby males.

This oblong-winged katydid female was emitting single clicks in response to the more complex songs of nearby males.

A four-spotted tree cricket had escaped from my grasp before I could photograph it. While looking for it on the ground where it seemed to have gone, my headlamp revealed something better.

A female tinkling ground cricket, only the second member of the species I have seen (despite hearing hundreds).

A female tinkling ground cricket, only the second member of the species I have seen (despite hearing hundreds).

A similar encounter came when I was trying to get a better photo of a melodious ground cricket at Indiana Dunes State Park. Digging through the leaf litter in the area from which a male’s song seemed to be coming, I turned up a female ground cricket.

When I examined the photos, though, I saw that the palps were white. This was a female confused ground cricket, another species that was singing in the area, and the first female confused I have seen.

When I examined the photos, though, I saw that the palps were white. This was a female confused ground cricket, another species that was singing in the area, and the first female confused I have seen.

One of the last places I visited this year was the Bong Recreation Area in Kenosha County, Wisconsin. The prairie area there is extensive, and has a good population of common meadow katydids.

Despite its name, the common meadow katydid is much less frequently encountered than two of its congeners, the gladiator and black-legged meadow katydids.

Despite its name, the common meadow katydid is much less frequently encountered than two of its congeners, the gladiator and black-legged meadow katydids.

There were a few broad-winged bush katydids in the prairie, but I wasn’t successful in stalking one. This Texas bush katydid had to substitute.

There were a few broad-winged bush katydids in the prairie, but I wasn’t successful in stalking one. This Texas bush katydid had to substitute.

Such encounters, sprinkled through the field season, make for good memories.

Melodious Ground Cricket

by Carl Strang

On Saturday I returned to the Indiana Dunes area. My first stop was the State Park, where I hoped to confirm my suspicion that the abundant trilling coming from the leaf litter in the forest south of the shrub swamp would prove to be the songs of melodious ground crickets. It was a cool morning, which didn’t deter the forest’s Carolina ground crickets, but kept the confused ground crickets quiet. As the morning warmed degree by degree, I heard more and more of the mystery songs.

This is a wet woodland, with scattered plants, a lot of rotting logs, and much of the ground covered by varying thicknesses of leaf litter from the shading trees.

Frequent pairs of large yellow slugs, apparently reproducing, indicated how damp the environment was.

My permit allowed me to pursue the singing crickets. I stalked to the spot where a song was being produced, and slowly moved, ultimately on my knees and shifting my head position, until I had a good idea of exactly where the song was coming from. Most of the time this was leaf litter piled against a rotting log. Then I variously lifted leaves one by one, grabbed a big double handful of leaves and tossed it onto a white t-shirt, or otherwise attempted to expose the singer. More than a dozen such efforts produced two sightings of tiny black ground crickets. Both were quick to jump impressive distances. One got away after giving me only a glimpse, but the other had the misfortune to bounce off a log, giving me a chance to catch him in my hands. I put him into a jar, and later transferred him to a cage and took him home. I needed to confirm that this cricket belonged to the mystery species rather than being a Carolina ground cricket (it wasn’t a confused, lacking the snow-white palps of that species).

The cage set up at home. I provided food, and kept the bottom of the cage moist.

The cricket took a while to get settled, but then in the quiet of the evening began to produce the beautiful high-pitched trill I was hoping to hear. Indeed his identity as a melodious ground cricket is all but confirmed.

Here he is, in appearance practically identical to the Carolina ground cricket and a few other common species.

At some point I will need to check a final point under the microscope, but for now I am happy to keep him alive, protect him from parasitoids, and enjoy his nightly concerts.

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