A New North for Nebraskas

by Carl Strang

The Nebraska conehead is a katydid whose northern range limit is within the Chicago region.

Nebraska coneheads can be green, like this one, or brown. The entire underside of the cone is black.

This insect of forest edges and open woodlands sings at night, its high-pitched buzzes readily audible through the window of a moving car. It is common and widespread in the southern counties of the Chicago region, but becomes less abundant, and more locally distributed, farther north. Entering this year, I had found it in nearly all the southern counties. There was a record in the literature for McHenry County, Illinois, but I had not found it there or in neighboring Lake County. I made it a focus for this year’s searching, and was able to complete the map. On July 30 I heard them in both the Lake and McHenry County portions of Chain O’Lakes State Park. I tried to find them in northern Lake County, Indiana, on August 2, but was unsuccessful. On August 11 I found a group of them a short distance north of the southern Lake County border.

Here’s another view.

Chain O’Lakes State Park is not far from Wisconsin, so on August 18 I drove the rural roads of southern Kenosha County, just north of the park. Though the habitat looked suitable in places, there were no Nebraska coneheads. They are already vanishingly thin in Lake and McHenry, so this was not surprising.

The Chicago region range map for the Nebraska conehead. Black dots indicate the counties where I have found the species. The red star marks Chain O’Lakes State Park, the northernmost known location in the region.

For my purposes, I am satisfied that I can close the book on Nebraska coneheads and focus on other species.

 

Advertisements

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.

 

How far North?

by Carl Strang

One of the projects in my singing insects study is tracing the boundaries of species ranges, and following how these are shifting in cases where they are expanding, usually northward. Two of the species I have been pursuing in recent days are the long-spurred meadow katydid and the Nebraska conehead. Several years ago I found a small population of long-spurred meadow katydids at south Blackwell Forest Preserve in DuPage County.

Some of the Blackwell katydids have this unusual black color added to the dorsal surface of the abdomen.

Some of the Blackwell katydids have this unusual black color added to the dorsal surface of the abdomen.

This little population is the northernmost I have found in DuPage County, and a recent search found none farther north. The similar situation in Cook County is a long established population at the Brookfield Zoo. My recent investigation there found one long-spurred meadow katydid a little more than two miles farther north, but none beyond that.

My current Chicago region map for the long-spurred meadow katydid. Black dots indicate counties where I have found the species to date. Red stars indicate the two northernmost known locations, at Blackwell Forest Preserve and along the Des Plaines River.

My current Chicago region map for the long-spurred meadow katydid. Black dots indicate counties where I have found the species to date. Red stars indicate the two northernmost known locations, at Blackwell Forest Preserve and along the Des Plaines River.

This year I found a new north for Nebraska coneheads, at the Carl R. Hansen Woods in northern Cook County.

Nebraska conehead

Nebraska conehead

A drive along rural roads north of that preserve failed to turn up an additional location.

The northern site for this study is indicated by the red star. The open circle in McHenry County represents an old report that I have not been able to confirm in the present day.

The northern site for this study is indicated by the red star. The open circle in McHenry County represents an old report that I have not been able to confirm in the present day.

These are two species for which, so far, there are no indications of expanding ranges in the Chicago region.

 

Parson’s Grove Visit

by Carl Strang

One evening last week I paid a visit to Parson’s Grove at Danada Forest Preserve. I felt that Nebraska coneheads were due to start singing, and Parson’s Grove has the largest population I have encountered in DuPage County, which makes it the northernmost significant population I have found to date in the Chicago region. There seemed to be more individuals singing that night than I remember from previous years. I tracked one down for a photo.

He proved to be a brown one. The conehead katydids all can be green or brown, but this is the first brown one of this species I have seen.

He proved to be a brown one. The conehead katydids all can be green or brown, but this is the first brown one of this species I have seen.

Another goal was to photograph a male rattler round-winged katydid, if any were going there. I have photos of a couple females, but lacked one of a male. I heard three at Parson’s Grove, and caught one in the open on a giant ragweed leaf.

My headlamp didn’t seem to disturb him as he casually groomed his feet.

My headlamp didn’t seem to disturb him as he casually groomed his feet.

The brown area on his back, which is part of the wings’ song-producing apparatus, is one distinguishing feature of males.

Parson’s Grove is a great place to hear a wide variety of nocturnal singing insects. DuPage County’s forest preserves provide a huge advantage to the region’s nature lovers, in that the preserves close an hour after sunset rather than right at sunset as is the case in the less enlightened surrounding counties.

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.

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.

Chasing Coneheads 2: Indiana Dunes

by Carl Strang

[Note: Gideon later wrote to share his conclusion that the coneheads we collected were in fact marsh coneheads. The individuals in that population are larger than the ones he was familiar with in Missouri, and the strange gray underside of the cone also was misleading. He later found slender coneheads in another part of their range.] Gideon Ney, Nathan Harness and I reconvened at Indiana Dunes National Lakeshore. We set up camp, but then had to wait out a long afternoon rain wondering if it would stop, if an evening’s search would be any good. The rain stopped an hour before dusk, and we set out prepared to wade through tall wet marsh grasses. We stopped at a corner of the Lakeshore’s Great Marsh, and traded stories as the light faded away. We started hearing the shrill buzzes of coneheads, and began to stalk them. Some of the early ones appeared to be marsh coneheads (Neoconocephalus palustris), which Gideon and Nathan had encountered in Missouri. Then we started catching different ones, and Gideon became increasingly excited as he ticked off characteristics, ultimately concluding that these were the long-sought slender coneheads.

Slender coneheads have medium-sized cones with nearly all the underside darkly pigmented. The Nebraska conehead is similarly marked, but occurs in wooded habitat rather than marsh, and has an interrupted rather than a continuous song.

Most of the ones we found were brown rather than green.

They usually sing head down. This one I disturbed, and he froze after changing position.

Nathan also found plenty of meadow katydids to study back in the lab.

Nathan and Gideon inventory their haul.

They took live katydids back to Missouri, so they can record their songs under controlled conditions in the lab and then get detailed DNA and other biochemical analyses to compare to other conehead species.

Ultimately Gideon hopes to collect slender coneheads from several locations. This species is interesting because it occurs in scattered, separated locations from the Atlantic coast to a site in northwest Illinois. How will its population genetics reflect this indication of a storied evolutionary history?

The night had one concluding chapter, which I’ll share in the next post.

Coneheads

by Carl Strang

The singing insect season is drawing to a close, and I have not mentioned one group to which I devoted some attention this season. The coneheaded katydids are a fairly diverse group of relatively large katydids characterized by cone-shaped structures that rise from the tops of their heads.

Nebraska conehead b

This is a Nebraska conehead. Its song consists of loud, shrill buzzes about 1.5 seconds long, with 1-second pauses between. It sings starting at dusk, in habitat that in my experience always has bushes and usually trees. The only location I have found so far with more than 3 or so singing individuals is Parson’s Grove at Danada Forest Preserve. The scattered bushes against the savanna edge seem to be ideal for this species.

There are two common, widely distributed coneheads in DuPage County’s meadows and prairies. The first to start singing, in the second half of July, is the sword-bearing conehead.

Sword-bearing 2b

Its rapidly ticking song has been compared to the sounds of a distant steam engine or a sewing machine. The other common meadow species is the round-tipped conehead.

Round-tipped conehead 3b

As you can see, these katydids look much alike. The round-tipped has a relatively short cone with a small black area at the tip (compare to the longer cone with a nearly all black surface on the Nebraska conehead, above).

Round-tipped conehead 5b

This one is more of a late season species, starting up in the second half of August and continuing through October. Its song to my ear is much like that of the Nebraska conehead, except that it has very long continuous buzzes rather than interrupted ones.

The possibility that I need to clear up is whether the robust conehead also is present. Its song is continuous, like that of the round-tipped, but reportedly is much louder and at a lower pitch. Its similar cone typically lacks the black tip, and body size is larger. I may have heard some of these at night while driving in past years, but so few in 2009 that I will have to hold this possibility for investigation until next year.

%d bloggers like this: