This year’s bioblitz, in the series sponsored by the Indiana Academy of Science, was a return to the site of the first such event that I joined in 2012, the Kankakee Sands Preserve in Newton County. The 2012 bioblitz took place in late July, so with a June 3 date this year there were fewer singing insects to observe. I sought without success to find new species to add to my site list, and ended up with 5 singing insects. Some were expected this early:
Sulfur-winged grasshopper, Arphia sulphuria
Others gave me first song dates for the year:
Eastern striped crickets (Miogryllus saussurei) were singing a week earlier than I had observed in any past year. This female climbed up onto one of the evening’s lit sheets.
When bioblitzes are scheduled this early in the season, I like to set up a sheet with a UV light in the evening and photograph moths. I also visit sheets operated by the Purdue University beetles team. Moths, especially their caterpillars, are ecologically significant and deserve attention in the bioblitzes. Here are some of the more attractive ones from this year.
The birch dagger (Acronicta betulae) is regarded as uncommon. Its larvae feed on river birch leaves. I photographed three dagger moth species. The great oak dagger (Acronicta lobeliae) was at home in the Conrad Station oak woodland.The white-spotted leafroller (Argyrotaenia alisellana) is another oak specialist.Tulip-tree beauty (Epimecis hortaria)Buck’s plume moth (Geina bucksi) is tiny, but its beautiful pattern deserves a close look. Green leuconycta (Leuconycta diphteroides)Moths need to be looked at closely, because there can be color variation among individuals of the same species. Here is one disparaged arches (Orthodes detracta).And here is another, which a first glance suggests must be a different species.Faint-spotted palthis (Palthis asopialis)Virginian tiger moth (Spilosoma virginica)
Pickings may be slim for singing insects in early-season bioblitzes, especially in more northern sites, but the opportunity to experience this nighttime diversity, and also the company of other researchers specializing in other groups of organisms, makes the trip worthwhile. There always is more to learn. For instance, while driving to Conrad Station at dusk, I stopped to escort a snake off the road.
I would have passed it off as a fox snake, but one of the more herpetological participants looked at the photo and taught me the differences between this bull snake and the fox snakes with which I am more familiar.
For many years, the Indiana Academy of Science has organized an annual bioblitz. This is a gathering of scientists, both professional and amateur, who spend a weekend compiling a list of all the species in their respective areas of expertise that they can find in a designated location. I first participated in the 2012 Kankakee Sands event, and it has been a highlight of each field season since. Last year’s bioblitz had to be postponed thanks to the pandemic, but we were able to resume the series this June in the Mosquito Creek area of Harrison County, bounded by a bend of the Ohio River.
Most of the bioblitzes have been early in the season, before most singing insects have matured, but the southern ones especially have provided experiences which have made them worthwhile for my research. One example is my first encountering the spring trig (Anaxipha vernalis) at the Connor Prairie bioblitz in 2013. The species then had not been formally described, and simply was listed in the Singing Insects of North America website (SINA) as “Anaxipha species G.” I later found a few in the southern edge of my study region, but most of my experiences with them have been through the bioblitzes.
This year they proved to be by far the most abundant singing insect at Mosquito Creek, and I was able to resolve a question that had bothered me. Spring trigs generally remain buried in dense grasses close to the ground, and are difficult to see. I had collected a male at Connor Prairie, and he had a head that was all dark brown. In a later bioblitz at Eagle Creek Park I had photographed a female, and her head was pale with a scrollwork pattern of dark lines:
This year I wanted to confirm this sexual difference, and was able to get a male and a female in the same jar. The head color difference was as I had noted before, the male’s uniformly dark:
Furthermore, the male’s abdomen was black or very dark brown, the female’s a much paler tan.
My first couple of hours of bioblitz work were spent in a grassy parking area at one of the Mosquito Creek sites.
I was struck by rapid sharp chirping around the grassy edge near the forest, the chirps contrasting with the spring trig continuo:
The chirps had the quality of field crickets, but were so compressed that the pulses could not be distinguished by ear. That combination of location and chirp quality pointed to southern wood cricket (Gryllus fultoni), a species I never had met. I flushed one out, and the combination of yellow cerci and brown wings on a generally black field cricket confirmed the identification:
Though southern wood crickets prefer to be in the forest, they have been shown to shift to the forest edge when their close relative, the northern wood cricket (G. vernalis), is present. This proved to be the case in the evening, when northern wood crickets started singing within the forest with their lower volume, less compressed chirps. This apparently is now only the second county where the southern wood cricket has been documented in Indiana.
A third species in that parking lot was the eastern striped cricket, Miogryllus saussurei (Tom Walker has recently added an interesting historical account of this species’ naming to SINA, and the next edition of my guide will replace the verticalis species name accordingly). I made a recording there of the distinctive buzzing chirps:
I needed to photograph a male, and succeeded in flushing one out:
I had hoped to find some exotic (to my experience) early season grasshoppers, but the only ones I found are common in the northern part of the state as well, the green-striped grasshopper (Chortophaga viridifasciata) and the sulfur-winged grasshopper (Arphia sulphurea). The latter were very dark brown with tan wing edges, and their hind wings were bright orange-yellow:
I found three more species. Two of these, a spring field cricket (Gryllus veletis) and a group of protean shieldbacks (Atlanticus testaceus) are common and familiar in the North, but a loud sharp trilling on the grounds of The Nature Conservancy’s headquarters grabbed my attention:
It was louder, had a more rapid pulse rate and slightly different pitch from the nearby spring trigs. I immediately thought of the southeastern field cricket (Gryllus rubens), which I had heard on visits to my brother’s residence in North Carolina. I had listed it as a possibility because the species had been documented once before in Indiana, a few counties west of Mosquito Creek. I was able to flush out the singer, and confirmed that it was a field cricket:
The southeastern field cricket is unusual for its genus in having long trilling songs rather than discrete chirps.
So there it is. The plant people list hundreds of species in these bioblitzes, birders find dozens, and I perennially have one of the lowest species counts. The experience always proves worthwhile, both for the experiences like the ones described here and enjoying the company of other field biologists.
One of my winter projects has been to write new sections for my singing insects guide which go into ecological topics. This was inspired by my reading a newly published textbook on landscape ecology (With, Kimberly A. 2019. Essentials of landscape ecology. Oxford University Press, Oxford, U.K. 641 pp). In the next few posts I will share parts of the added sections. Today’s focus is the impact of the last continental glacier on the landscape and selected insect species:
Though the focus in most of this guide is on the individual species of singing insects, the field of landscape ecology provides a framework of broader patterns and questions for which the ecologically diverse singing insects provide a suitable lens.
Landscape ecology considers geographical patterns and dynamics of their change across time. Any complete biological understanding of the Chicago region must include not only what is here now but also how it got that way. Fortunately, we don’t have to go back too far geologically speaking, as our landscape is less than 20,000 years old. Three major lobes of the most recent continental glacier flowed down from the North and scoured our region’s bedrock, then began their final retreat around 18,000 years ago. As the glacier melted, with occasional periods of stalling when the push from the North was balanced by melting at the edge, it left behind a variably deep layer of various kinds of deposits. The topography was more elevated in the morainal arcs where the melt was stalled for a time, lower and flatter when the melt-back was more uniform and rapid. Occasional pocks formed where blocks of glacial ice were buried and later melted, resulting in small lakes, bogs and other wetlands. Our rivers had their start as glacial meltwater drainage streams. The Lake Michigan Lobe of the glacier picked up and crushed the softer shale from the bottom of what was to become that lake, so it left behind deposits heavy in clay west and southwest of the lake. When glacial crunching and meltwater eroded harder igneous and metamorphic rocks the ice had transported from Canada, gravel and sand resulted. Quartz sand, the most erosion-resistant component of such rocks, accumulated especially around the edge of Lake Michigan and the tributaries of the Kankakee River, which started as a glacial meltwater drainage stream originating in the part of the region covered by the glacier’s Saginaw Lobe.
This glacial history impacted our singing insect fauna in various ways. Some species require, or at least are only abundant, on sandy soils. These include the green-winged and northern dusk-singing cicadas, whose nymphs live on buried plant roots, and some of the grasshoppers, for which the sandy substrate for egg-laying and/or a poor-soil plant community is an important habitat component. A couple of species, the gray ground cricket and the seaside grasshopper, are limited to the beaches and dunes around the Lake Michigan edge.
The beaches at different points on the Lake Michigan shore have different compositions, resulting in selection for different colors in the seaside grasshopper. Here, at Illinois Beach State Park, there is a greater mix of different colors of ground igneous and metamorphic rocks.
The beaches of the Indiana Dunes are a more uniform quartz sand. Here, two seaside grasshoppers (same species as in the previous picture) would be nearly invisible if they were not flashing their inner femur colors at one another.
Kames are gravel hills formed by waterfalls within the melting glacier, and they provide a well-drained substrate. Isolated populations of sulfur-winged grasshoppers and tinkling ground crickets live on a kame in the Lulu Lake Nature Preserve in northern Walworth County, Wisconsin.
Exposed gravel on part of the kame at Lulu Lake.
All species were pushed south by the glacier, surviving in what is now the southern U.S. and being influenced by selective forces then and during the advance north as the climate moderated and plant communities spread back over the barren glacial deposits. Most of our familiar prairie and forest plant species were restricted to rather small refuges in the South during the glacial maximum, though oaks and hickories occupied a large part of the southern U.S.
Black oak savanna, Kankakee County
As the glacier melted back, open sedge tundra with some black spruce trees invaded first, then white spruces filled in to form a recognizable northern coniferous forest until around 15,000 years ago. By around 12,000 years ago most of our landscape was a mix of deciduous species, including woodlands with lots of oaks. Beginning around 10,000 years ago there was a drying period, which led to the spread of prairie through our area. The prairie then retreated as the climate became wetter, so that by 6200 years ago the western part of our region was a prairie with islands of woodlands and wetlands, grading to forest in the eastern part. This reflects a gradient of increasing moisture from west to east, mediated by the flow of wet air circulating north from the Gulf of Mexico. The drier prairies were maintained by fires which frequently knocked back woody plants that otherwise would have converted even the western part of the region into woodlands. The wooded islands within the prairie were not randomly located, but survived where rivers, other wetlands, and topographic breaks shielded certain spots from prairie fires pushed by the prevailing westerly winds. The upshot for our singing insects is a diverse landscape that to this day contains species specializing in prairie, woodland and various wetland habitats, as well as some that thrive around the edges between habitat types. A few species may be relicts of earlier changes in this history. For instance, the delicate meadow katydid, now apparently extinct in the region, is abundant in prairies to the west and probably accompanied the prairie advance. By the early 20th Century it was known in a very few scattered locations. I have not been able to find it anywhere in the present day.
Delicate meadow katydid females have longer ovipositors than their close relatives.
In the early part of the season, from April to early July, my research focus is on those species of singing insects which matured from overwintering nymphs, plus some small early-season cicadas. This is a minority of species, as most of the crickets, katydids, and singing grasshoppers mature after the middle of July, having wintered as relatively secure eggs and needing time to grow up.
I was able to close the book on northern wood crickets last month, and the story here is a sad one. This forest-dwelling member of the field cricket group had been reported from two northern Indiana sites by W.S. Blatchley in 1903. As far as I know, no one has sought them since then in the northern part of the state. Last year I determined that they no longer occur where Blatchley found them. This year I checked the largest other eight forests in the Indiana portion of my study region. If they ever were there, they are gone now. I suspect that forest fragmentation for agriculture and other purposes is responsible for the loss. Blatchley’s detailed descriptions leave no doubt that he knew how to recognize the species.
This northern wood cricket is from the northernmost site where I know they still occur, Eagle Creek Park in Indianapolis.
I was able to close the book on another southern species, the spring trig, in June.
This tiny, early-season cricket is common in southern Indiana.
I have found a few scattered groups of spring trigs in southernmost Fulton and Jasper Counties in Indiana. A thorough search failed to turn them up in neighboring Pulaski and Newton Counties. I may check again in a few years, on the possibility that the species is expanding northward.
One positive result was finding sulfur-winged grasshoppers in the East Main Street Prairie of Cary, Illinois. This adds McHenry to the counties where I have found the species. They probably occur in every county in my region but are common only on sandy or gravelly soils such as Cary’s kame-like hills. I have learned of another candidate site which may add Fulton County, Indiana, next year.
Sulfur-winged grasshoppers are characterized by bright yellow hind wings, which they rattle in flight to produce their song.
Prairie cicadas started a little late this year. I was pleased to find that management efforts to remove brush from the West Chicago Prairie Forest Preserve near my home appears to have paid off in both rebound of diverse prairie vegetation and an increase in the cicada numbers.
Prairie cicadas, are tiny, around an inch long.
Failure to perform such restoration work has a cost. Once known to occur in Kankakee County, prairie cicadas apparently are gone from there, the prairies having been degraded by brush, teasel and other invasive plants.
A final story is that of the periodical cicadas. In each cycle since 1973, the main appearance of 17-year cicadas in Chicago’s western suburbs has been preceded by a significant, 4-year-early emergence. This happened in 1969, 1986, and 2003. I suspect that in a small part of this area, all the cicadas now have switched to the early time. If you have done the math, you realize that it may happen again next year. One predictor to watch for are what I call oops cicadas, a few individuals who jump the gun by a year, or miss the main emergence and come out a year late. As expected, this has been happening this spring. I have heard 3 individuals myself in two cities and seen photos of the insects from 3 more. Counting and mapping them will be a highlight of next year’s early field season.
I predict that some areas will have good numbers of 17-year cicadas next year.
The sulfur-winged grasshopper is an early season species that I wanted to close out this year, in my regional survey of singing insects. Though it probably occurs in all 22 of the counties in my survey region, it is common only on soils heavy in gravel or sand. I targeted 3 counties with such soils where I had not yet found this crepitating (wing-rattling) grasshopper: Walworth in Wisconsin, LaPorte in Indiana, and Berrien in Michigan.
Success came first at the Lulu Lake natural area in Walworth County. I did not find it in the Nature Conservancy portion of the property, but gravel-hill openings in the forest on the state nature preserve side proved to have a good population.
One of the series of photos documenting sulfur-winged grasshoppers at Lulu Lake.
Subsequently I found them in the Lake Michigan coastal zone in LaPorte and Berrien Counties. In the process I learned a final lesson from the grasshoppers: they don’t like loose dune sand, and need to be sought a little farther inland, where plants and the accumulation of organic matter have made the soil more stable. That closes the book on sulfur-winged grasshoppers as far as my survey is concerned, and I will put my time into other species at this point of the season in future years.
The updated Chicago region sulfur-winged grasshopper map, marking counties where I have found it.
The main focus of my research these days is traveling through the 22 counties of my survey area, seeking the singing insects that live in the Chicago region. I am building on previous years’ work, filling gaps in range maps. The currency I work in thus is county records. There are around 100 species known to have occurred here, and so the maximum total would be 2200 county records. This is not going to be the eventual result, however, because many of the species live only in limited areas within the region. For instance, last week I closed the book on the green-winged cicada.
This distant photo is the best I have so far of a green-winged cicada.
I do not expect to find green-winged cicadas beyond the 10 marked counties.
They occur only in sand soil woodlands within the region. Though other counties have some areas with sand soils, I have searched them and failed to find the species. Their numbers clearly diminish at the periphery of their range. Four of these county records have been from this year.
Other species are widespread, and ultimately I expect to find them in every county. Two early season species now have filled maps as a result of my travels this spring and early summer: Roesel’s katydid, and gladiator meadow katydid.
Roesel’s katydid
There is learning involved in the process. Some species which historically have occurred in the area I have not yet found. Others I have found once or twice. At some point I become familiar enough with a species that I know how to find it. Then I seek it out in the appropriate habitat in the counties where I haven’t found it. The sulfur-winged grasshopper is an instructive example. This year I made a push to complete the map for this early-season species. Though I ran out of time before the end of its season, I got close.
Updated map for sulfur-winged grasshopper (open circles represent historical records)
Next year I will check sandy sites in two of the counties in Wisconsin, LaPorte County in Indiana, and Berrien County in Michigan. Though I suspect that sulfur-winged grasshoppers occur in every county, they are very few and hard to find away from sand soils. Though my own county of DuPage is marked, it is a clay soil county and over the many years I have lived here I have encountered fewer than 5 sulfur-wings in DuPage.
A final example is the northern bush katydid. I had heard two of these in the early summer of 2007, in woodlands in my county. I had heard none since. But a few days ago I went back to one of those sites and tried listening at night with the SongFinder, a device which reduces the pitch of sounds. Lo and behold, I discovered that Parson’s Grove at Danada Forest Preserve has a lot of northern bush katydids. I hadn’t realized that it was the deterioration of my hearing with age that had prevented my detecting them. Now I anticipate finding them in every county in the region.
So far this year I have accumulated 47 county records. I expect to end up with more than last year’s 174.
The most fruitful recent singing insects search was at the Kankakee Sands preserve in Kankakee County, which has become one of my favorites for species that affiliate with sand-soil habitats. The June 28 visit yielded 3 county records, two of which were of familiar species, Roesel’s katydid and green-winged cicada.
Grasshoppers were building up their diversity at the site. Sulfur-winged grasshoppers still were going, and the season’s first mottled sand grasshopper also flashed his wings.
This was by far the earliest I have found this sand-soil specialist.
Then in the prairie beyond the savanna I started to hear the zuzz-zuzz-zuzz of stridulating grasshoppers. I had a hard time getting a look at who it might be. Eventually I saw a possible candidate.
This grasshopper has a somewhat slanted face, and color markings reminiscent of stridulating grasshoppers in genus Orphulella.
Study of the photos, however, led to an identification as the meadow purple-striped grasshopper, Hesperotettix viridis, in the non-singing spur-throated grasshopper group. As I waded through the grasses I flushed out a couple really odd grasshoppers that begged to be photographed.
The blade-like antennas, subtle striping pattern, and especially the gangly skinniness of the critter were distinctive.
They reminded me of high school basketball players whose growth spurts have given them impressive height, but whose strength and coordination have some catching up to do. Though I saw and photographed only the minute-winged females, my identification and study convinced me that these were the stridulators. The short-winged toothpick grasshopper is well named, seeming to be constructed of toothpicks. It is a member of the slant-faced stridulating subfamily, and is described as being a frequent singer. The species, also known by the more mundane name of bunchgrass grasshopper (Pseudopomala brachyptera), now is removed from my hypothetical list for my survey region.
Though my main research focus is singing insects, I don’t end up photographing them much, as I am listening for them rather than looking for them. Sulfur-winged grasshoppers continued to be an early-season focus.
Though I added several more county records for the species, there was not additional range in their color variation. This female was at Cook County’s Bluff Spring Fen.
Here is a typical dark male, Illinois Beach State Park.
Not much different, this male was around the corner of Lake Michigan at Indiana Dunes National Lakeshore.
Only 8 species of singing insects could be found at Goose Pond. There will be many more there later in the season.
Green-striped grasshoppers still were displaying, but their days are numbered.
Spring field crickets seldom come into view. This female was a challenge to photograph as she crawled among the grasses.
This katydid nymph climbed up onto the sheet illuminated by the UV light. I am reluctant to say which conehead species she might be.
The season seems barely begun, but already I am closing the book on two species.
The Vermont Cemetery Prairie Preserve in Will County reportedly is one of the few places in the Chicago region which still harbors prairie cicadas. They were done, however, by the time I got there on June 26.
I have just 3 sites to check next year as good candidates for persisting prairie cicada populations. Protean shieldbacks also apparently are done. I added only 3 county records for them in their brief 2016 season. This was a wakeup call, and I will need to get on my horse right away when they start next year.
Memorial Day weekend brought a reunion with my brother, Gary, in our hometown of Culver, Indiana. Among the many reminiscences and activities were a few visits to places where I hoped to find early season singing grasshopper species. By the time I got home I had accumulated 5 county records for sulfur-winged grasshoppers.
This is the source of the name. I was careful in handling them, and released them all unharmed.
Along the way I found color variations, between the genders and between locations.
Here is a typical female at Memorial Forest, Marshall County.
Another female from the same population was yellower.
On the whole, though, females were much less variable than males.
All the females had broad blue bands on their tibias.
Males generally were darker than females and, as is typical in grasshoppers, were smaller.
At some sites, males had striking yellow edges on their forewings.
From above, the pale streak resembles a piece of dead grass stem, and breaks up the general dark mass of the grasshopper’s outline.
Elsewhere males had little or no pale edging.
Tibia color also was not consistent. This seems surprising, as the behavior of grasshoppers when they meet often includes a display of tibias.
Sometimes males showed the typical grasshopper pattern of matching female tibia colors, as in this individual from Newton County, Indiana.
Often, though, the lower tibias were completely black (Memorial Forest).
There still is time to find sulfur-winged grasshoppers in more of the 22 counties of the region I am surveying, and I will be interested in seeing how these variations play out.
A few hours of singing insect searching over the weekend produced 8 county records (across 3 counties), and some photos I’d been hoping to get. High on the list of priorities for the latter this year was the green-winged cicada, Diceroprocta vitripennis. I found a number of them singing Saturday at Jasper-Pulaski State Fish & Wildlife Area in Indiana. Finding a singing cicada up in a tree is a challenge when it can be done at all. The good part is that I found one.
The less than great part is that the only line of sight was from a distance and through a canopy hole, so I will hope for a better opportunity at another time.
I also heard one of that species singing Sunday at Braidwood Dunes in Will County, my first Illinois location. So far all have been in black oak sand savannas.
Back at J-P, I was able to catch a sulfur-winged grasshopper, so as to get a photo of the bright yellow hind wing.
If anything, the yellow was more intense than the photo indicates.
The critter stayed put when I released it, making a portrait possible.
Though study of reference material confirmed the ID, this one was much paler than the individual I photographed within 50 feet of this location last year.
That 2013 hopper may have had the more typical color pattern. I saw its twin at Braidwood Sunday.
Nearby at J-P was a pair of grasshoppers that begged to be photographed. They do not belong to either of the singing subfamilies of grasshoppers, but they were attractive to look at.
These appear to be narrow-winged grasshoppers, Melanoplus angustipennis.
As I drove out of J-P, I was arrested by this group of plants beside the road.
Brilliant red flowers topped the tall stems.
They appear to be targeting hummingbirds as pollinators.
The foliage accounts for the odd name (for an herbaceous plant) of standing cypress.
Gilia rubra is native to the southern states, but has established some colonies of escapes from cultivation in the sand counties of northwestern Indiana.
Nature Inquiries 