Landscape Ecology of Singing Insects 2: Human Influences

by Carl Strang

The previous post illustrated that the Chicago region has been a dynamically changing landscape through the recent millennia, but that now is overshadowed by the alterations our own species has made. Burgeoning human numbers have overwhelmed the planet’s ecosystems, and the native habitats described earlier mostly have been replaced by agriculture and urban growth in the Chicago region. One of the more dramatic changes is the loss of the Kankakee wetland, once described as the Everglades of the North. That vast wetland was drained for agriculture, and only a few pockets of it survive in preserves. Much of the Kankakee River in Indiana is now a straight channel with constructed high levee banks. Other smaller wetlands received similar treatment, with drainage ditches spreading across the agricultural portion of the region. This is not universally devastating to wetland species. Northern mole crickets, for instance, occasionally can be found along drainage ditches.

Drainage ditch, upper reaches of the Kankakee River, St. Joseph County, Indiana. Note farm fields on both sides.

Prairie mostly has been replaced by agricultural fields, and fire suppression has led to its invasion by woody plants. Specialists such as the prairie meadow katydid, prairie cicada and short-winged toothpick grasshopper are hard to find.

Prairie meadow katydid

My singing insects research has required a lot of driving to reach the relatively tiny surviving preserves and parks to which many of the species are now restricted. Much management effort is required in these little islands to maintain their habitats. There are exceptions, of course. Many other species have thrived under our influence. These are mainly weedy ones such as the striped ground cricket, short-winged meadow katydid and Carolina grasshopper, which do well in disturbed habitats, along with woodland edge species such as the greater angle-wing, snowy tree cricket, and jumping bush cricket, which can meet their needs in residential neighborhoods dominated by lawns and scattered trees and shrubs.

Jumping bush cricket

Habitat destruction is not the only human influence. Climate change is the probable cause of northward range expansions by several singing insect species, and it likely will lead to the extinction of the sphagnum ground cricket from the region as the sphagnum bogs dry up. Say’s cicada and some northern grasshoppers already appear to be pushed out.

Sphagnum ground cricket

Climate change isn’t simply a matter of rising temperatures, as the term “global warming” may seem to imply. Global warming is an accurate enough term, as the simplest way to measure climate change is to track the global average temperature. But the point is that our changes to the Earth’s thin skin of atmosphere are increasing its held solar energy. That energy alters patterns of atmospheric flow and the behavior of storms. Droughts, more frequent flood-causing rains, and seasonal increases or decreases in temperature that seem abnormal are examples of results we observe locally. The singing insects are forced to adjust as best they can. Droughts force sphagnum ground crickets into the wettest parts of their bogs. The severe drought of 2012 concentrated wetland meadow katydids and marsh coneheads into the small portions of the Great Marsh in the Indiana Dunes National Park that remained wet. Oblong-winged meadow katydids may be pre-adapted to such year-to-year variability. Blatchley (1920) observed that their eggs, laid in moist soil, can take 2-3 years to hatch. In my travels through the region I failed to hear a single individual in the years 2010 and 2019, but in other years they have been abundant and widespread. Some of the cicadas and other species may have similar flexibilities.

Oblong-winged katydid

People also have introduced plant species from other parts of the world which, released from the consumers and competitors which hold them in check in their native lands, have become invasive plants here. Their unfair competitive advantage has led to their displacing the region’s native vegetation in an increasing number of places. This is most evident in our wetlands. Wetland meadow katydids and other singing insects are limited to places where native wetland grasses have not been supplanted by reed canary grass, common reed, purple loosestrife, and hybrid cattails. These invasive plants are proving difficult to control, and the outlook is not good for species such as the dusky-faced meadow katydid and marsh conehead. To my knowledge the once relatively widespread stripe-faced meadow katydid now is confined to a single site, and the slender conehead, never known from many locations, apparently is gone from the region.

Stripe-faced meadow katydid

Introductions have not been limited to plants. Several species of singing insects also have been imported. Roesel’s katydid is the most common of these in our region. A European predaceous katydid, Roesel’s was introduced to the Montreal, Quebec, area several decades ago and expanded from there. They occur in open habitats with tall herbaceous vegetation throughout the Chicago region. Japanese burrowing crickets are thought to have arrived at the port of Mobile and spread out from there. They are abundant as far north as Indianapolis, and common in Rensselaer in the southern part of our region. With scattered new appearances each year occurring as far north as DuPage County in Illinois, so far, I expect them to become widespread and abundant here. The tropical house cricket represents the possibility of other, short-term introductions that are unlikely to persist in our climate.

Roesel’s katydid

Wetland Singing Insects Update

by Carl Strang

For years, now, my biggest conservation concern among the singing insects has been in the wetlands. Though our historically abundant prairies in the Chicago region were diminished nearly to nothing by 19th– and 20th-century agriculture, preservation and restoration projects across the region have halted and, to a small degree, reversed that trend. The same could be said for savannas, and our forests did not suffer as much.

Wetlands, like prairies, declined thanks to agriculture, but a new challenge continues to threaten their integrity: invasive wetland plants. Four of these are especially problematic: common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), hybrid cattails (Typha x glauca), and purple loosestrife (Lythrum salicaria). These plants, released from consumers and competitors, have displaced the diverse native species in a large and increasing portion of our wetland acreage. The loss of native wetland grasses, especially, appears to account for the difficulty I am experiencing in finding wetland katydids.

Reed canary grass

Two species that were here historically, I have not found at all: the delicate meadow katydid (Orchelimum delicatum), and the slender conehead (Neoconocephalus lyristes). In the past these were known to occur in four and three, respectively, of the Chicago region’s 22 counties, and I am nearly out of places to check where they might still live. The stripe-faced meadow katydid (O. concinnum), once found in 8 of the counties, appears to be down to a single population at Illinois Beach State Park.

Stripe-faced meadow katydid

Two wetland katydids are doing well. Gladiator meadow katydids (O. gladiator) and black-legged meadow katydids (O. nigripes) are tolerant of the invasive plants, and remain common in every county.

That leaves an in-between category of wetland singing insects that apparently are limited to invasives-free wetlands, and are managing to hang on in a few to several sites. Northern mole crickets (Neocurtilla hexadactyla) occur in wet prairies as well as marshes. In 2017 I added records for two more sites, one of which represented an additional county record. To date I have found them in 10 counties, and remain optimistic that I can add more populations to the inventory.

Dusky-faced meadow katydids (O. campestre) historically were ubiquitous in our marshes. To date I have found them only in marshes with minimal impact by the invasive plants. These katydids seem able to persist in relatively small wetland areas, however, and each year I have been able to add new populations to my list. In 2017 I found them in the Indiana Kankakee Sands preserve, adding Newton County to the record, and in the Tefft Savanna preserve in Jasper County, also a county record. That brings to seven the number of counties where I have found the species, but there are seven more where it once lived, but where my search has been unsuccessful. Dusky-faced meadow katydids also proved this year to be abundant in the panne wetlands at West Beach in the Indiana Dunes National Lakeshore. That was a good find, but I had hoped for delicate meadow katydids there.

Female dusky-faced meadow katydid, Tefft Savanna

Finally, this year I added a third population and county for the nimble meadow katydid (O. volantum). They were singing from arrowheads (Sagittaria sp.) mixed with cattails along Grant Creek in the Midewin National Tallgrass Prairie. That find was made from a kayak, and that is the vehicle from which further searching for the species will need to happen, as this species likes plants growing in relatively deep water. Some places which historically held nimble meadow katydids no longer have them, but several other sites remain for me to check in future years.

Singing Insects Wrap-Up

by Carl Strang

October’s cold gradually is silencing another year’s array of singing insects. In recent weeks I have made some final trips to squeeze just a little more data out of the season.

In early September I succeeded in catching an Autumn yellow-winged grasshopper with actual yellow wings (most of them in the region have had red-orange hind wings).

In early September I succeeded in catching an Autumn yellow-winged grasshopper with actual yellow wings (most of them in the region have had red-orange hind wings).

On October 5 I made a final trip up to Illinois Beach State Park, and found some stripe-faced meadow katydids still singing.

On October 5 I made a final trip up to Illinois Beach State Park, and found some stripe-faced meadow katydids still singing.

By then, of course, they had developed their full color.

By then, of course, they had developed their full color.

I was able to complete a photo series on the species with some cerci shots.

I was able to complete a photo series on the species with some cerci shots.

On October 11 I returned to Gar Creek Forest Preserve in Kankakee County and made more recordings. I did not find any more Cuban ground crickets crossing the trail, but was surprised by several variegated ground crickets doing so.

I had never before seen a variegated ground cricket, like this male, wandering in the open.

I had never before seen a variegated ground cricket, like this male, wandering in the open.

This female has an interesting pattern of pale dashes on her wings.

This female has an interesting pattern of pale dashes on her wings.

It’s reasonable to assume that they walk about at night for most of the season, but like many singing insects extend their usual nighttime activity into the day as temperatures cool. I was glad to get the visual confirmation that this species is at the site along with the (probable) Cubans.

Probably my last singing insect photo series for 2016 was of this spotted ground cricket at St. James Farm on October 18.

Probably my last singing insect photo series for 2016 was of this spotted ground cricket at St. James Farm on October 18.

 

Beyond the Dead River

by Carl Strang

The Dead River, in Illinois Beach State Park, is so named because most of the time it appears not to be flowing. It ends just shy of the edge of Lake Michigan, a sand bar between the two. Reportedly there are times when enough water comes into it that it breaks through this narrow barrier. The area south of that river is highly protected, and to enter it I needed a permit from the Illinois Nature Preserves Commission.

The Dead River and its extensions are free of invasive wetlands plants, though there are some unconnected wetlands in the area for which that is not the case.

The Dead River and its extensions are free of invasive wetlands plants, though there are some unconnected wetlands in the area for which that is not the case.

Sand savanna and prairie occupy the areas between the wetlands.

Sand savanna and prairie occupy the spaces between the wetlands.

My main goal was to survey the area for wetland singing insects. This was one of my last hopes for finding slender coneheads, but sadly there were none. I am beginning to think they have gone extinct in Illinois. On a much brighter note, I found that the area harbors a huge population of stripe-faced meadow katydids.

This male had developed his full facial color, but an intervening grass blade marred the portrait.

This male had developed his full facial color, but an intervening grass blade marred the portrait.

Profile view of a female.

Profile view of a female.

Illinois Beach remains the only place where I have found this wetland katydid, which even historically was never widely distributed.

I also heard a little chorus of nimble meadow katydids, out in the middle of a river offshoot in a patch of deeper-water arrowheads. There probably are other such groups elsewhere in the area. I plan to get a better idea of their numbers next year. This is the second place I have found them in the region, and the first for Illinois. I spent several days in my kayak this season searching for nimble meadow katydids in places in Illinois and Indiana where they were known in earlier decades.

Apparently the American lotus, shown here, and the yellow pond lily, which filled most of those sites, are too coarse for nimble meadow katydids.

Apparently the American lotus, shown here, and the yellow pond lily, which filled most of those sites, are too coarse for nimble meadow katydids.

I have found them among pickerel weeds and arrowheads, and historically they were known in patches of water knotweeds.

Water knotweed, like those others, is of intermediate coarseness.

Water knotweed, like those others, is of intermediate coarseness.

I suspect that the turbulence created by power boats favors the heavier plants that the insect apparently abhors. I wonder if Illinois Beach State Park also may harbor the last Illinois population of nimble meadow katydids. I have a few more places to check next year.

 

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.

 

Sound Ideas: Three Meadow Katydids

by Carl Strang

Today I am sharing recordings of 3 species of large meadow katydids (genus Orchelimum). One way or another their songs all fit the ticks-and-buzz pattern characteristic of their group. I will order them idiosyncratically, by how well I can hear them in the field. I will be interested in any comments on how well you can hear them in these recordings. The first is our most common species in the genus, the black-legged meadow katydid O. nigripes.

Black-legged meadow katydid

Black-legged meadow katydid

This was a very warm individual who was rushing the ticks. I render the pattern tickety-buzz, as there usually are 3 ticks leading directly into the buzz, with a brief pause before the next set. This species usually can be found in or near wetlands. I can hear its song unaided without any trouble.

Next up is the long-spurred meadow katydid, O. silvaticum.

Long-spurred meadow katydid

Long-spurred meadow katydid

Here the ticks have much the same quality as the buzz, several very brief rattles that merge into the rattling buzz. This is a katydid of woods edges and adjacent areas with tall herbaceous vegetation. I can hear some of these unaided in the field, on a calm day without other competing sounds, or when there are plenty of reflecting surfaces, but usually I need the SongFinder pitch-reducing device to detect them. I can hear this recording clearly, though.

Finally, here is a species I first encountered this past season, the stripe-faced meadow katydid, O. concinnum. It is a specialist in certain kinds of wetlands, and is much less common than the others.

Stripe-faced meadow katydid

Stripe-faced meadow katydid

This one I can’t hear at all from more than a few feet away, and I can barely hear it in this recording. I really need the SongFinder for this species. The ticks are more numerous, more separated, and more irregularly spaced, than in the black-leg.

The Magic Swale

by Carl Strang

After a summer that seemed dominated by rain and cool weather, late September brought a period of sun and warmth, offering hope of salvaging a field season that had been, on the whole, uninspiring. The Bendix Woods bioblitz brought some good results, and I was happy with my experiences at Midewin and Indiana Dunes National Lakeshore, so things were looking up. On my next stop I was passing a swale when I heard some curious songs through the SongFinder pitch-lowering device that led me to pause.

It doesn’t look like much in the photo, but this wet-bottomed depression had one quality increasingly hard to find in a wetland: a lack of invasive marsh plants.

It doesn’t look like much in the photo, but this wet-bottomed depression had one quality increasingly hard to find in a wetland: a lack of invasive marsh plants.

Long-tailed meadow katydids, not an everyday insect, were a good find, but they were not producing the mystery song.

Long-tailed meadow katydids, not an everyday insect, were a good find, but they were not producing the mystery song.

Reportedly a common species, the marsh meadow grasshopper had evaded my wish for a photo op until this day.

Reportedly a common species, the marsh meadow grasshopper had evaded my wish for a photo op until this day.

One of them stridulated before my eyes, rapidly raising and lowering its hind legs to scrape against the folded wings, producing the characteristic zuzz-zuzz-zuzz… of the slant-faced stridulating grasshopper subfamily.

The marsh meadow grasshopper provides yet another variation in the structural beauty of grasshoppers. The little rectangular shape above the antennae is one of the diagnostic features of this species.

The marsh meadow grasshopper provides yet another variation in the structural beauty of grasshoppers. The little rectangular shape above the antennae is one of the diagnostic features of this species.

Eventually the SongFinder led me to the singers in the swale. They will endure as the highlight of this year’s field season.

Stripe-faced meadow katydids!

Stripe-faced meadow katydids!

This is a species I have sought for years. The hints in the literature are vague in some ways, contradictory in others. I have slogged through marshes, bogs and marl in counties throughout the Chicago region, and yet here, where I would not have expected to find it, was a population of Orchelimum concinnum. They were beautiful, like the other wetland members of their genus, and well named with that ornamental stripe down the front of the head.

The stripe is not simple, but multicolored as you can see.

The stripe is not simple, but multicolored as you can see.

The song was faint to my ear. I needed to be within a few feet to hear it unaided. A few irregularly spaced ticks (3 or 4 in some individuals, 6 or 7 in others) led into a buzz a few seconds long. Increasingly I am leaning more and more on the SongFinder, but perhaps with that knowledge I will have more success in finding other populations of stripe-faced meadow katydids.

Where are the Conservatives?

by Carl Strang

It should be obvious that this title is not a political reference. In this election year both political conservatives and liberals are easy to find as they loudly and shrilly make their cases against each other, trying to attract voters (hm, reminds me of singing insects for some reason). The conservatives I am concerned about here are some of the wetland species of singing insects, habitat specialists that are found only within narrow ranges of ecological parameters and are sensitive to invasive species and other disruptions. Much of my research this year is focused on finding conservative species from my hypothetical list for the region.

I haven’t had a lot of luck with wetland conservatives. The northern mole cricket was one, but I still have not found them anywhere but Houghton Lake. The marsh conehead was another. We thought we also found slender coneheads at Indiana Dunes National Lakeshore, but Gideon discovered when he returned to his lab that they all were marsh coneheads as well, misleading because they were outside the size range of that species he was familiar with in Missouri.

Gideon also learned that the underside of the cone should be black, not gray as it was on the marsh coneheads we found.

But what about the several species of wetland meadow katydids in genus Orchelimum? Regionally there should be four species I haven’t yet found: dusky-faced, stripe-faced, delicate and nimble meadow katydids all have been elusive. I should have found dusky-faced meadow katydids, at least, because they are described as being common in a wide range of marshes. Instead I am finding lots of black-legged meadow katydids, a marsh species that spills into drier areas adjacent to wetlands.

Black-legged meadow katydid

Black-legs sing so loudly, day and night, that I wonder how earlier researchers heard the other wetland species. I wonder if black-legs have become more abundant, conceivably pushing the others out. Have I not been looking in the right places or in the right way? Is the lack of success this year a consequence of the drought? Certainly it takes some effort this year to get wet feet in the marshes. I will continue to look. Last week at Chain O’Lakes State Park in Illinois I saw a number of Orchelimum nymphs that were relatively plain and green.

This female meadow katydid nymph is recognized as an Orchelimum by the curved ovipositor.

On the other hand, black-legs don’t get their full colors until after they mature.

This newly molted adult male black-legged meadow katydid still has not developed his full coloration.

I will continue to look this year, and hope for better conditions next year.

Three Missing Meadow Katydids

by Carl Strang

The final three species of singing insects that are reported to occur in northeast Illinois and northwest Indiana but that I have not yet found are meadow katydids in genus Orchelimum. These three are placed in the region in the 20th Century mainly from three published sources, Hebard (1934; Illinois Orthoptera), McCafferty and Stein (1976; crickets and katydids of Indiana), and Thomas and Alexander (1962; a paper that focused on these three species). The most abundant of these reportedly is the dusky-faced meadow katydid. Here is the map for that species in the Singing Insects of North America (SINA) website.

Thomas and Alexander write that the dusky-faced meadow katydid originally was described from northern Indiana in 1893, and their paper is the source for most records of that species in our region in the SINA database (in Indiana: Starke, Kosciusko, Lake, Porter, LaPorte, Marshall, and Fulton Counties; in Illinois: Lake, McHenry, Cook, Will, and DuPage Counties). Its face is said to be amber, with a red tinge. One early author described its northern Indiana habitat as upland pastures and dryer prairies, and seldom associated with lakes. Thomas and Alexander found it to be common, especially as compared to the stripe-faced and delicate meadow katydids, occurring in a wide range of marshes, “usually in vegetation over standing water,” and especially associated with grasses. The song is high pitched; I may need the SongFinder to hear it. Some sing during the day, but most singing is done from dusk into the night. Sometimes the song resembles those of the following two species, but usually it is different in having longer buzzes (more than 1-3 seconds), or longer strings of ticks (more than 5), or in eliminating ticks altogether (meadow katydid songs for the most part are variations on the pattern of several discrete, rapid ticks followed by a buzz). I am inclined to include this species in the broad range of wetlands I will continue to visit in my surveys.

Early descriptions placed the stripe-faced meadow katydid in dense grasses and sedges near ponds and streams. One account associated it with grasses and sedges around tamarack swamps and lakes. Here is its map from SINA.

Hebard gave swamps and bogs as habitat for the stripe-faced meadow katydid in Illinois. In the northeast part of the state he listed Glen Ellyn and the tamarack zone at Volo Bog as locations. Thomas and Alexander found it to be very limited in its distribution, occurring in “a few northern relict marl bogs and other alkaline situations.” The adult’s face is marked by a prominent stripe down its center, which Hebard says appears only after the final instar has matured. The song is high pitched; I may need the SongFinder to hear it. Some sing during the day, but most singing is done dusk into the night. To the ear the songs of this and the following species are nearly identical, having tick and buzz elements. Ticks are single rather than doubled, however. Indiana counties for which there are records are Lake, Starke, Fulton, Marshall, Kosciusko, and Porter. Illinois records are from Lake and Cook Counties. The old fish hatchery in Marshall County at Culver is a marl site worth exploring for this species.

Hebard found only females of the final species, the delicate meadow katydid, and his only northeast Illinois locations were Beach (at Lake Michigan in Lake County) and Algonquin (McHenry County). According to Thomas and Alexander, early authors stated that this species occurred in low meadows near large lakes in the Indiana counties of Marshall and Starke. These records are included in the species’ SINA map:

Thomas and Alexander say from their own experience that it is “largely restricted to swales adjacent to sand dunes or sand beaches, where it is often associated with …[the grass] Calamagrostis canadensis.” Its face is green. The song is high pitched; I may need the SongFinder to hear it. Some sing during the day, but most singing is done dusk into the night. To the ear the songs of the delicate and stripe-faced meadow katydids are nearly identical, having tick and buzz elements. Ticks may be doubled in this species, however. Places to seek it are Indiana Dunes State Park, Illinois Beach State Park, and marshes and lakes in Marshall and Starke Counties, Indiana.

%d bloggers like this: