Small Wonders at Illinois Beach

by Carl Strang

Two targets for my friends from Ohio and West Virginia were stripe-faced meadow katydids and gray ground crickets, both of which can be found at Illinois Beach State Park. The stripe-faceds proved to be in their early-stage colors.

Even this nymph has the facial stripe, but it is brown and relatively fuzzy-edged compared to what it ultimately will become. New adults have the same brown colors, even though they are mature enough to sing and to mate.

Even this nymph has the facial stripe, but it is brown and relatively fuzzy-edged compared to what it ultimately will become. New adults have the same brown colors, even though they are mature enough to sing and to mate.

The nymphs and new adults were all in shades of tan and brown. We saw one or two adults which were beginning to develop their green body colors, and the more distinct facial features.

The nymphs and new adults were all in shades of tan and brown. We saw one or two adults which were beginning to develop their green body colors, and the more distinct facial features.

Gray ground crickets have been a challenge, and prior to this year I had gotten only a couple brief glimpses of them. This time I caught one, allowing us to take photos before releasing our subject back into the dunes.

The cricket was a female, probably made vulnerable by her moving about seeking a singing male.

The cricket was a female, probably made vulnerable by her moving about seeking a singing male.

Gray ground crickets are well named. I especially like the head stripes and the little dark rectangular markings on the wings.

Gray ground crickets are well named. I especially like the head stripes and the little dark rectangular markings on the wings.

We found other critters of interest along the way, of course.

Kiowa rangeland grasshoppers occupy the same ecological zone as the gray ground cricket.

Kiowa rangeland grasshoppers occupy the same ecological zone as the gray ground cricket.

Scattered cottonwood trees among the dunes were hosts for this striking beetle, a cottonwood borer.

Scattered cottonwood trees among the dunes were hosts for this striking beetle, a cottonwood borer.

The loudest nighttime insect singer was the robust conehead. We saw both brown and green males.

The loudest nighttime insect singer was the robust conehead. We saw both brown and green males.

 

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A Night Excursion to Kankakee Sands

by Carl Strang

Kankakee Sands is a Nature Conservancy site in Newton County, Indiana. Except for the early-season bioblitz there a few years ago, my visits have been in the daytime. Last week I made a nighttime trip to Kankakee Sands. This netted several new species observations for the county as well as the site, the best of which was a grasshopper I had not encountered before.

The handsome grasshopper is well named. A spindly little guy, he was rather jumpy after I caught him in the grasses and released him on the gravel parking lot.

The handsome grasshopper is well named. A spindly little guy, he was rather jumpy after I caught him in the grasses and released him on the gravel parking lot.

All of that was incidental to my main goal, however, which was to continue my collaboration with Gideon Ney of the University of Missouri. Gideon’s lab, led by Johannes Schul, is working out the evolutionary history and relationships of the conehead katydids, genus Neoconocephalus. Two of them, the robust conehead and the false robust conehead, are sibling species reliably separated mainly by differences in their songs.

Robust conehead…or is it?

Robust conehead…or is it?

I stopped at several locations, recording singing males and then trying to catch them. I need practice. They were quick to stop singing as I approached. Ultimately I was able to accumulate 12 recordings, catching the males producing 6 of them.

Here they are, ready to be packed for overnight shipping along with the recordings.

Here they are, ready to be packed for overnight shipping along with the recordings.

A couple of the songs seemed different to my ear, so I am hopeful that the effort will result in a mix of the two species, and an education on what to look for in sonographs of the recordings so I don’t have to capture them in the other counties of my survey region.

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.

 

Sound Ideas: Coneheads

by Carl Strang

When I mention the coneheads to people unfamiliar with singing insects, the response almost always is a smile. I have to agree: one reason why the slightly musical conehead is my favorite singing insect (at the moment) is that name. Our coneheads are all katydids in genus Neoconocephalus. I have been fortunate to spend some time in the field with Gideon Ney, a Ph.D. student at the University of Missouri who is working out of a lab led by Johannes Schul that has done a lot of work with the evolution of that group. Thanks to Gideon I am aware of two species of coneheads that are not supposed to occur as far north as the Chicago region, but turn out to be at least locally common. Today I share recordings of the 6 documented species in the region. Warning: these are not delightfully musical or even (despite the name mentioned above) slightly so. We’ll ease into it with one that is somewhat pleasant to hear: the sword-bearing conehead. Its song:

That recording was made in a grassy upland meadow, typical habitat for the species, but close enough to the edge of the woods that a few common true katydids came through loud and clear. The conehead’s song is the continuous string of rasping ticks or brief buzzes. It has been compared to the sound of a sewing machine or a distant steam locomotive.

The sword-bearing conehead is named for the very long, straight ovipositor on the female.

The sword-bearing conehead is named for the very long, straight ovipositor on the female.

The next species also has a discontinuous song. The slightly musical conehead was given that name because W.T. Davis, who described it, thought it was not very loud (though he later changed his mind on that point).

The rasping sounds are easy for me to hear even with my older ears. This is a wetland species, and the males typically sing in unison.

The coneheads are named for the structure on the tip of the head, especially prominent in the slightly musical conehead.

The coneheads are named for the structure on the tip of the head, especially prominent in the slightly musical conehead.

Another species with an interrupted song is the Nebraska conehead.

The buzzes are not as rough as in the previous species, and will be heard in bushy undergrowth of woodlands, or sometimes bushes out in fields. In the southern part of the Chicago region, where the species is more common, the males sometimes sing in unison as well.

Male coneheads often sing head down. It has been speculated that the cone helps them penetrate the vegetation beneath when they are disturbed and drop to hide. Nebraska coneheads have medium sized, all black cone undersides.

Male coneheads often sing head down. It has been speculated that the cone helps them penetrate the vegetation beneath when they are disturbed and drop to hide. Nebraska coneheads have medium sized, all black cone undersides.

The remaining 3 species all have continuous buzzes. Most common region-wide is the round-tipped conehead, a katydid of meadows and roadsides.

Listen for a crackling sound in this continuous buzz.

Here the cone is short, round, and has a small black area near the tip.

Here the cone is short, round, and has a small black area near the tip.

Next is the marsh conehead, which so far has turned up only in the marshes of the Indiana Dunes parks.

The sound resembles that of the round-tipped, but comes from a wetland rather than dry upland habitat.

The cone of the marsh conehead may be all green as in this female, or show variable darkness of color.

The cone of the marsh conehead may be all green as in this female, or show variable darkness of color.

For the grand finale, here is the very loud song of the robust conehead:

This can be so loud as to be painful to the ears. It carries for long distances, as you may imagine, and is easy to hear from a car at any speed.

The robust conehead’s cone is unmarked and proportionately short. Any conehead species can come in green or brown.

The robust conehead’s cone is unmarked and proportionately short. Any conehead species can come in green or brown.

The robust conehead is most abundant in areas with dry sandy soils. Its habitat range is fairly broad, from open woodlands to prairies to corn fields.

There are at least two other species which are supposed to occur in the region, but which I have not found. Perhaps next winter I will have recordings of false robust coneheads and slender coneheads to share.

Sound Ideas: An Odd Trio

by Carl Strang

Today’s chapter in the Sound Ideas winter series is a recording from the evening of September 4 last year. I made it in the Miller Woods portion of the Indiana Dunes National Lakeshore. Three very different singing insects can be heard distinctly throughout:

The principal target of this recording produced the annoying, continuous buzzing sound. If you had been there, you would have remarked at how loud this insect was. It was a robust conehead.

Male robust conehead, singing posture

Male robust conehead, singing posture

This katydid has a sibling species, creatively named the false robust conehead (Neoconocephalus bivocatus). I haven’t documented bivocatus in the Chicago region, but there are a couple old possible records, so occasionally I record an individual and check the pulse rate and pattern. So far, all have been good old Neoconocephalus robustus.

The other two members of that night’s trio both produced regular, brief chirps: one higher pitched and very regular in its rhythm, the other much lower and a little less regular. The higher pitched singer is famous for the way its chirping rate varies with temperature: count the chirps in 13 seconds, and add 40 to get the degrees Fahrenheit. We know this singer as the snowy tree cricket.

Snowy tree cricket male, taking a break from singing to snack on skin.

Snowy tree cricket male, taking a break from singing to snack on skin.

That leaves the bass section. The lower pitched continuo is the product of a northern mole cricket. This swale area of Miller Woods is one of only 3 locations where I have found this species to date. I don’t have a photo to show you. True to his name, the mole cricket sings from within his tunnel, and I haven’t yet had a photo op with the critter.

Ah, yes. I see an insistent hand upraised in the back of the class. Yes? Ah, very good. Yes, there is a fourth, more intermittent performer here. Those few added chirps are a fall field cricket’s, practically ubiquitous at this point in the season, and determined to insert himself into any ensemble.

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.

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.

Return to Illinois Beach

by Carl Strang

A return to Illinois Beach State Park was called for last week, as my first visit was early enough in the season that more singing insects could have become active since. For instance, gray ground crickets were not singing yet in early August, but by last week they were active.

Gray ground crickets are common in the scattered clumps of grasses and other plants behind the Great Lakes beaches.

Hearing is not seeing, however, and despite my best efforts I could not expose a gray ground cricket for a photograph. They were in the larger patches of vegetation and trapped oak leaves, and it was too easy for them to sneak away when I tried lifting leaves and plant stems to look for the hidden singers. That disappointment was relieved somewhat by an amusing dung beetle.

It was having difficulty moving this far-from-spherical chunk.

I had better luck with grasshoppers. Some members of the grasshopper subfamily Oedipodinae are in the park. These qualify as singing insects, as their displays include wing-rattling flights. I found two species. One, a darker form, was in the savanna near the Dead River.

This appears to be a Boll’s grasshopper, a relatively dark individual of the species. The yellow and black hind wings are hidden when folded at rest.

The beach was another grasshopper habitat.

Some grasshoppers prefer this more open vegetation structure.

A common species was pale and well camouflaged.

This one appears to be a seaside grasshopper.

In the night, I followed a tree cricket’s song as it trilled in the gray ground cricket habitat.

The antenna spots don’t show here, but they clearly revealed that this was a four-spotted tree cricket.

Robust coneheads had become common in the campground woods.

This male sings from a patch of big bluestem grass within the savanna.

I found a few more species to add to the site list, but none were particularly uncommon.

Marsh Conehead

by Carl Strang

My memory of the great marsh at Indiana Dunes State Park was of an extensive, grass dominated wetland. Perhaps it was once, but today it has succeeded to a shrub swamp.

A tower along one of the trails provides an overlook.

A shrub swamp is a valuable habitat, but for my purposes there are relatively few pockets of the grasses that would harbor the greatest diversity of singing insects.

Here is one such pocket along the north edge.

The drought that has dried the wetlands to a large degree no doubt also contributed to the low numbers of katydids and crickets I found in these grassy patches. One individual of interest, however, was a female conehead.

She instinctively trusted her camouflage, which allowed me to approach and catch her.

Not knowing which characteristics were essential and not wanting to kill her unnecessarily (though I did have the necessary permits), I took a series of photos.

The underside of the cone, its shape and its markings, are an important feature in conehead identification.

In many groups of katydids and crickets, ovipositor shape and size also is helpful in identifying females.

Here is the ovipositor of the female I caught.

Habitat also is helpful, in this case the marsh. Only two species of coneheads with unmarked cones are expected in marshes, the marsh conehead and the robust conehead. In this case the pinched, slightly elongate cone and the ovipositor shorter than the length of the femur point to marsh conehead. The only additional feature I should have checked was the insect’s length, a point to keep in mind for the future.

This finding, which seconds the identification of marsh coneheads that the Missouri students and I found at the nearby National Lakeshore, continues to open my eyes to the limitation of past records. Published accounts don’t show marsh coneheads this far north in Indiana. The same was true for slightly musical coneheads. Consequently I did not have either species on my hypothetical list for the region. Do these discoveries represent range extensions, or simply a mismatch between spotty past surveys of spottily distributed species? It may not be possible to say, but I have to be open to the possibility that my hypothetical list likewise may be incomplete for other groups of singing insects.

Maxinkuckee Wetlands

by Carl Strang

Another area near Culver, Indiana that I wanted to check for singing insects was the Maxinkuckee Wetlands, a state conservation area. Much of it I will need to access by kayak on another occasion. My daytime visit did not produce much, but when I returned at night I was pleased to find a population of slightly musical coneheads, which I first had encountered in the previous week at Indiana Dunes National Lakeshore.

Unlike the mole cricket, as mentioned in yesterday’s post, the slightly musical conehead has a buzzing song.

Along the road edge of the property I heard a different conehead, and traced the song to a small oak.

The impressive volume of the song up close was enough to confirm the singer as a robust conehead. The dry habitat and cone free of black markings support the identification.

Maxinkuckee Wetlands is another site calling for continued exploration.

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