A Pause in the Action

by Carl A. Strang

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.

Advertisements

2019 Bioblitz

by Carl A. Strang

Each year the Indiana Academy of Science co-hosts a bioblitz somewhere in that state. This year’s site was The Center at Donaldson, which includes a retreat center and Ancilla College, plus surrounding properties. I always take the singing insects in this annual 24-hour count of species, but no one came to cover Lepidoptera or Odonata in 2019, so I appended them to my commitment. That is just as well, because these events are scheduled early enough in the season that few singing insects have reached the adult stage.

Some Roesel’s katydids matured in time for the bioblitz.

Two of the five singing insect species I found were common early species that were nearly finished, two were common mid-season species recently coming into song, and one of them provided an observation of significance. The eastern striped cricket is thinly scattered in northwest Indiana, possibly expanding into that region from the south or west. A single male singing in the evening provided a Marshall County record, a full county’s width farther east than I have observed them before.

I enjoyed re-acquainting myself with the beauty of dragonflies, damselflies, butterflies and moths, and photographed many of them.

The widow skimmer was the most abundant dragonfly.

Most of the eastern or common pondhawks still were green. Males will change to blue over time.

The Halloween pennant pleases the eye.

There weren’t many damselflies. Here, a blue-fronted dancer.

Newly emerged eastern forktail females are orange.

A few monarchs graced the grounds.

There were many great spangled fritillaries, plus this meadow fritillary.

I encountered a few moths during the day, but most came to my ultraviolet light setup in the forest, or the Purdue team’s assorted bright lights in the open. Moths are underappreciated for their beauty, diversity, and ecological significance.

Large lace-border, Scopula limboundata

Reversed haploa, Haploa reversa

Painted lichen moth, Hypoprepia fucosa

Delicate cycnia, Cycnia tenera

Isabella tiger moth, Pyrrharctia Isabella

Imperial moth, Eacles imperialis

Hermit sphinx, Lintneria eremitus

Snowy-shouldered acleris, Acleris nivisellana

Oblique-banded leafroller, Choristoneura rosaceana

Grape leaffolder, Desmia funeralis

Grape plume moth, Geina periscelidactylus

Large maple spanworm, Prochoerodes lineola

Lesser maple spanworm, Macaria pustularia

Small engrailed, Ectropis crepuscularia

Ovate dagger, Acronicta ovata

Pink-barred pseudostrotia, Pseudostrotia carneola

The Hebrew, Polygrammate hebraeicum

The brother, Raphia frater

Along the way I encountered a few other species to add to the species count.

Narrow-winged grasshoppers were common on the bioblitz base camp’s sandy hill.

A Pennsylvania wood cockroach came to the UV light.

The light also drew this striking summer fishfly.

 

Some Cicada Site Maps

by Carl Strang

Today I close this series of posts on my site mapping project. Three of our Chicago region cicadas’ maps revealed interesting patterns that raised questions for me. Let’s start with the green-winged cicada (Diceroprocta vitripennis).

Green-winged cicada

Green-winged cicada all sites map

This is a species that is limited to sand soil areas along the edge of Lake Michigan and the Kankakee River. I was a little surprised that the latter sites all were south of the river, but that could be in part because I haven’t visited many sites on the north side. Now let’s consider another sand-soil species, the northern dusk-singing cicada (Neotibicen auletes).

Northern dusk-singing cicada, museum specimen

Northern dusk-singing cicada all sites map

What strikes me here is that the northern dusk-singing cicada extends much farther into the sandy southeastern counties. I’m a bit puzzled by this, as there is habitat in southeastern Starke County and southwestern Marshall County which seems very similar to places where I have found green-winged cicadas farther west. The only possibility I have come up with so far is that the green-winged cicada is smaller and weaker, and may not be able to find mates as readily in the fringes of its range.

A final case study, and the one that intrigues me most of all, is that of the swamp cicada (Neotibicen tibicen).

Swamp cicada

Swamp cicada all sites map

There are plenty of sites with swamp cicadas in the eastern two ranks of Indiana counties plus Berrien County, Michigan. That connects them to Cleveland, where Lisa Rainsong reports this as one of the most abundant cicadas. I had not realized, until I made this map, that I have found them only adjacent to the Kankakee River farther west in Indiana, plus the Momence Wetlands site in eastern Kankakee County, Illinois. I have spent plenty of time along that river farther west and have made no further observations. But then swamp cicadas show up again as scattered individuals and small groups in DuPage County and parts of the adjacent counties. For now I have to regard this as a disjunct part of the species’ range. Perhaps a few wandering individuals occasionally provide gene flow into this isolated northwestern group, but otherwise I wonder how long it has been separate in this way.

Site Map Fuzzy Boundaries

by Carl Strang

In the previous post I described my winter project of creating new maps showing all the sites where I have found each singing insect species in the Chicago region. A few of these produced surprises. Take the Texas bush katydid (Scudderia texensis), for instance.

Texas bush katydid

The all-sites map for Texas bush katydids.

The proportion of sites where I have observed this species is noticeably higher west of the Indiana border. Texas bush katydids occur through much of the eastern U.S., but they seem to thin out significantly in the eastern part of this region. I had no idea until I finished this map.

A similar surprise awaited in the maps for long-tailed meadow katydids (Conocephalus attenuatus) and black-sided meadow katydids (C. nigropleurum), two small wetland species.

Long-tailed meadow katydid

Black-sided meadow katydid, one of our most colorful singing insects

The all-sites map for long-tailed meadow katydids.

The all-sites map for black-sided meadow katydids.

As you can see, these are two species I don’t run into very often. What intrigues me is that I have found both only in the northern part of the region. Historically, at least, their ranges have extended well into southern Indiana, but is that still the case? Might these be examples of species losing the southern part of their ranges to climate change? This is one question I don’t think I have enough lifetime left to pursue myself, but perhaps others will be able to show that these species still are around farther south.

A final case for today is that of the tinkling ground cricket (Allonemobius tinnulus).

Tinkling ground cricket. Reddish tones distinguish this woodland-edge species.

Tinkling ground cricket all sites map

Here the map doesn’t tell the whole story. The sites in Indiana and the more southern Illinois counties have lots of tinkling ground crickets. The Cook, Kane and DuPage County sites represent observations of single individuals or, at most, fewer than ten. This seems to point to a drastic thinning northward, and makes the Lake County (Illinois) and Walworth County (Wisconsin) observations seem suspect. But going back to my field notes, I find that the Illinois Beach State Park and Lulu Lake Nature Preserve observations were of large, if isolated populations. What may distinguish them is the sand soil at Illinois Beach and similar gravelly soil at Lulu Lake. In DuPage, Kane and that part of Cook County the soils are clay based. So why haven’t I found tinkling ground crickets on the sandy soils of municipal parks in Wisconsin’s Racine and Kenosha Counties? Scientists love mysteries.

Site Map Project

by Carl Strang

Up to this point I have reported singing insect distributions in the Chicago region at the county level. For instance, here is an Allard’s ground cricket (Allonemobius allardi) and its species distribution by county.

Male Allard’s ground cricket

The black dots simply show that I have found Allard’s in every county of my study region.

But I have a lot more data than that which I wanted to share. Also, I thought that maybe a finer grained mapping approach might reveal new questions for me to investigate. I had a spreadsheet with a species list for every site I have visited. So, I recently created a series of maps showing the sites where I have found each species over the years. Here is the resulting map for Allard’s ground cricket:

Filled circles indicate sites where I have observed Allard’s ground crickets. Open circles are places I have visited where I haven’t (yet) noted that species.

As you can see, this is a widespread and frequently encountered cricket. The map reveals significant areas with no sites. Some of these are vast empty (from a biodiversity standpoint) agricultural regions, but still I should give them more attention.

One more example for today. The long-spurred meadow katydid (Orchelimum silvaticum) reaches its northern range limit in the Chicago region.

Long-spurred meadow katydid, male

The county-level map showed this, but the site level map makes it even clearer.

The northernmost sites where I have found long-spurred meadow katydids line up impressively at the same latitude.

These two examples simply emphasize conclusions I had drawn previously. Some intriguing questions were raised in other cases, as I will share in upcoming posts.

Shaking Out the Photo Bag

by Carl Strang

Before I get going on a new series of posts, I want to share a few photos that didn’t fit into last year’s topics.

This seemed to be a good year for gray treefrogs across the region. I frequently ran into small ones.

Gray treefrogs can change colors, making themselves green to blend in.

For some reason, they often rested on milkweed leaves.

It was a good year of singing insect field work. Plenty of questions remain unanswered.

One of the smaller ones was the identity of this grasshopper nymph at the Indiana Kankakee Sands. My best guess is sprinkled grasshopper, which I found there in adult form later in the season.

An interesting observation in the Tefft Savanna Nature Preserve (within Indiana’s Jasper-Pulaski Fish & Wildlife Area) was that short-winged green grasshoppers (Dichromorpha viridis) were the usual green color in wetlands but were brown in the savannas.

A mating pair of brown variants.

Late in the season I visited my friends Lisa Rainsong and Wendy Partridge, who live in the Cleveland suburbs. One goal was to see jumping bush crickets out in the foliage and branches of trees and shrubs. In the Chicago region they almost always stick to the trunks of trees and are difficult to see.

Sure enough, within a few minutes of searching I found a singing male in a bush.

They have an odd angular appearance, as though roughly carved from wood.

That’s it for now. Soon I will share results of a productive winter project.

The Tiny Ones

by Carl Strang

One of my goals this year was to achieve some clarity with two of the tiniest singing insects in the Chicago region. The variegated ground cricket (Neonemobius variegatus) and Cuban ground cricket (N. cubensis) are only a quarter to a third of an inch long. They are so unobtrusive, with their low-volume trills and hidden haunts, that you have to listen for them even to know they are around. Both species have rapid trills with crescendo starts, and unless you have perfect pitch and better hearing than me, telling their songs apart means working from sound recordings and getting technical.

Variegated ground cricket

Cuban ground cricket

My accumulated recordings of Neonemobius songs fall into two clusters, demarcated by a space that has remained remarkably consistent.

The dots in this graph each represent a recording of a Neonemobius cricket song, analyzed in the computer. The pulses represent the speed at which the cricket rubs his wings together to produce the song, and the frequency is the highness or lowness of the song’s pitch. Both measures increase with temperature. Note that variegated ground cricket songs fall into the upper left portion of the graph, Cuban ground cricket songs lower right. Dashed lines are my eyeball estimates of the space between the two clusters of points.

Variegated ground crickets vibrate their wings more slowly than Cuban ground crickets, yet have higher-pitched songs at a given temperature. This was the tentative conclusion I had drawn, but I needed some validation, and got it in October.

Here I have to back up a bit. I had found variegated ground crickets in the Chicago region, and would not have considered the possibility of Cuban ground crickets without the work of Lisa Rainsong. Cuban ground crickets had been known as a southern species until Lisa found them to be abundant in Cleveland. Her discovery alerted me to the possibility that they also might have reached the Chicago region. That possibility was realized when I found Cuban ground crickets in Gar Creek Forest Preserve in Kankakee County, Illinois. A captive Gar Creek Cuban ground cricket anchored the right-hand portion of the graph (yellow dots, yellow line).

A few observations of variegated ground crickets in previous years fell into the left-hand cluster, but I needed more. This year a captive variegated ground cricket from Gar Creek, which has both species, provided a series of recordings at various temperatures which fell as expected (red dots, red line).

Early in October I visited Lisa and her partner Wendy Partridge, and they showed me an area where Cuban ground crickets are abundant.

This meadow in the North Chagrin Reservation, a Cleveland Metroparks site, is packed with Cuban ground crickets. Lisa and Wendy check out tree crickets down the trail.

My recordings of two individuals at that site fit nicely into the previously established Cuban ground cricket cluster (green dots).

The final touch for 2018 came on October 18. I had 3 recordings, from 2006-2018, from north Blackwell Forest Preserve in DuPage County, all of which fit into the Cuban ground cricket cluster. Despite a few frosty nights, Neonemobius crickets had survived and were singing. I succeeded in flushing out one of these, and he was indeed a Cuban ground cricket. I regard this as a final validation of the graph. Now I need to go back to most of the 22 counties of the Chicago region in future years, and discover where each of these two species occurs.

Revised distribution of variegated ground crickets in the Chicago region, based mainly on analysis of sound recordings.

Revised distribution of Cuban ground crickets. One or both of the two species occur in every county, but I have not yet made sound recordings everywhere I heard Neonemobius crickets singing.

This story is an excellent example of hidden surprises that are waiting for researchers to uncover.

More Range Jumps

by Carl Strang

One recurring theme of my singing insects survey work is the northward extension of species’ ranges. Late in this year’s field season, three more species turned up significantly north of where I had found them before. One of these discoveries was made by Nancy Collins, who found broad-winged tree crickets (Oecanthus latipennis) half a county north of the Illinois border in Kenosha County, Wisconsin, more than 30 miles beyond where I had found them before.

Broad-winged tree cricket

I had not found this species in the northernmost row of Illinois counties, but I hadn’t looked for them there in recent years. Inspired by Nancy’s discovery, I did some searching and found them in Lake County at Chain O’Lakes State Park. Next year I want to seek them in McHenry County, Illinois, and Walworth and Racine Counties, Wisconsin (unless, of course, Nancy finds them there first).

The handsome trig (Phyllopalpus pulchellus) surprised me last year by turning up in sites across the southern half of my home county of DuPage in Illinois.

Handsome trig

I set the modest goal this year of seeking them in Kane County, just west of DuPage. Recently I succeeded in that, finding a group of them a little west of where I had found them in DuPage, but that was not surprising. What bowled me over was finding a small population of them in the East Main Street Prairie park in Cary. This is 22 miles, more than half a county, farther north, McHenry County being just north of Kane. This continued the pattern of handsome trigs popping up in separate scattered locations, because I tried to find them in northern Kane County and western Lake County, areas not far from Cary, without success.

The third species is one I have written about several times before, because it is spreading quickly, and soon becomes abundant in areas behind the front of its expansion. This is the jumping bush cricket (Orocharis saltator).

Jumping bush cricket

Last year I encountered a small population of jumping bush crickets in Wauconda, Lake County, Illinois. This was a good 12 miles north of where I had found them before. I still suspect that these were inadvertently transported there by people, and I wondered if they could reproduce successfully. Indeed there were even more males singing in that spot this year. The surprise was finding them in towns all along the west bank of the Fox River, nearly to the northern border of Kane County. This is a few miles south of Wauconda’s latitude, but a search of the southeastern corner of McHenry County, between the two locations, failed to turn them up. To be continued in future years…

Berrien Explorations

by Carl Strang

The end of August found me in Berrien County, Michigan. The first stop was the Butternut Creek Fen preserve, where I met tree cricket specialist Nancy Collins. We spent an afternoon and evening seeking tamarack tree crickets, which had been found there years ago. There are abundant tamarack trees, but we were puzzled by the crickets’ no-show. None sang, and hours of arm-tiring sweeping of foliage with long-handled nets, as well as visual scanning of branches, were fruitless. We found other species, though, and provided the site owners with a list of what we observed.

When Nancy found this fork-tailed bush katydid I was hopeful that it would prove to be a rarer cousin, the treetop bush katydid, but no dice.

Oblong-winged katydids also are at the site. My new white chamber setup worked well in the back of the car.

The next day I wandered in Berrien, St. Joseph and LaPorte Counties. The best find was a new site for me, Glassman Park in Berrien County. I bypassed some nice-looking forest, then was captured by a mundane looking grassy area adjacent to the I-94 right-of-way. It proved to have some interesting grasshoppers.

Most of these proved to be pasture grasshoppers, only the second population of this locally distributed species I have found in my study region.

A second species had a much different look.

The handsome grasshopper has an even more slant-faced profile.

With a color pattern like this, the handsome grasshopper is well named.

The day was my final in Berrien County for 2018, but there is more singing insect work to be done there in coming years. That is bound to include at least one more listening stop at Butternut Creek.

 

Hitchhiker Surprise

by Carl Strang

In the last week of August I pushed to close the book on melodious ground crickets (Eunemobius melodius) in the Chicago region. I found that a marginal 2017 sound recording in DuPage County, Illinois, in fact was a Say’s trig, failed to find melodious ground crickets in Kane and Kendall Counties, and found them at a site in St. Joseph County, Indiana. This left Jasper County as the remaining candidate county where I had not found the species. I had found them in floodplain forests in all the other counties bordering the Kankakee River, but there are few places in Jasper County where the river intersects public roads. Otherwise the only possibility was floodplain wetlands in the Jasper-Pulaski Fish and Wildlife Area, and they are not there. On August 26 I checked the places along the river, and though I could see likely habitats from the road, all were on posted private property. Here is the final map:

Map of the Chicago region, black dots indicating the counties where I have found melodious ground crickets. They probably also occur in Jasper County on private property.

I was happy to close the book on melodious ground crickets, but the highlight of the day was a hitchhiker. As I pulled away from a road that dead-ended at an extension of the river, I noticed a cricket on my windshield that I did not recognize. I stopped the car and caught the cricket.

The brown wings with yellow borders were vaguely familiar.

After returning home I was inspired to slap together a makeshift white chamber, inspired by Wil Hershberger’s work, in order to take portrait photos of the stranger.

I thought I had seen photos of crickets like this, and a little research turned up the identification: restless bush cricket (Hapithus agitator). The Kankakee River fringe in Jasper County is now the second-farthest-north location where the species has been found, according to the Singing Insects of North America website (a site in Massachusetts is the northernmost). I will add a page to my singing insects guide for the species, but there’s an asterisk. Restless bush crickets are widespread in the eastern U.S., but they are known to sing only in Texas and Florida.

« Older entries

%d bloggers like this: