One Last Look Back

by Carl Strang

My recent blog posts have shared highlights of this year’s field season, as I searched for singing insects in the 22-county area I define as the Chicago region. Those accounts haven’t told the whole story, though, and I have a few last photos to shake out of the bag. These fill out some of the experience of doing this kind of regional study.

For instance, other animals have enhanced the delight.

The chalk-fronted corporal is a dragonfly I have encountered only in the northern portion of the region, in this case at the Lulu Lake Nature Preserve in northern Walworth County, Wisconsin.

Walsh’s grasshopper was a new one for me. Not a singing species, but an interesting find at the Poverty Prairie in DuPage County’s Waterfall Glen Forest Preserve.

Turkey vultures assemble at dusk on the Culver, Indiana, water tower. My travels take me back to my home town a few times each season.

Interesting and beautiful scenes are to be found in the relatively undisturbed wild areas which are my main destinations.

An early evening rainbow at Conrad Station in the Indiana Kankakee Sands presaged a thunderstorm-dodging drive home on July 2.

Pinholes between tree leaves cast solar eclipse shadows at Blackwell Forest Preserve. Though the moon covered around 90% of the sun at peak, I detected no change in singing insect activity.

One of the more beautiful scenes was this panne in the Indiana dunes.

I had hoped to find delicate meadow katydids in the pannes. Dusky-faced meadow katydids were a good find there, but that species has a solid hold in other dunes wetlands.

The Pembroke Savanna in the Illinois Kankakee Sands is one of my favorite sites.

I believe these white pines at Warren Dunes State Park in Berrien County, Michigan, are the same ones where Richard Alexander found treetop bush katydids in 1971. He described the trees as small, but all are tall now. They still foster pine tree crickets, but I did not find any bush katydids.

I ended up with 115 county records for the season, totaling all newly found singing insect species over all the counties.

So far, I have found sprinkled grasshoppers only in oak savannas on sand soils.

Dusky-faced meadow katydids at the Indiana Kankakee Sands were a Newton County record.

This curve-tailed bush katydid at the Jasper-Pulaski Fish and Wildlife Area in Indiana provided a Jasper County record for my study.

I found a healthy population of long-tailed meadow katydids, including this brown-legged male, at Ferson Creek Fen in Kane County.

The Ferson Creek population also had green-legged variants, including this female.

Lisa Rainsong, Wendy Partridge and I drove south to Loda Prairie to check out the bush cicadas there. I concluded this year that the species does not occur in the Chicago region.

This Texas bush katydid was singing in early October at Springbrook Prairie Forest Preserve, DuPage County. I had an observation of this species on October 17, my latest ever in the region.

Most of the long winter remains, and as I compile data, write reports, and visit museums, I will be looking forward to another collection of rich experiences as I resume my field study in 2018.

 

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Adventures with Lisa and Wendy

by Carl Strang

Lisa Rainsong and Wendy Partridge are two admirable women from the Cleveland area. For years I have been corresponding with Lisa about our parallel explorations of singing insects in our respective regions. They honored me with a visit over the Labor Day weekend. We spent two full days site-hopping in northwest Indiana.

Wendy and Lisa stalk a long-spurred meadow katydid at Indiana Dunes State Park.

Wendy and Lisa stalk a long-spurred meadow katydid at Indiana Dunes State Park.

This was a three-way learning exchange. I provided local knowledge of species with which Lisa and Wendy needed more experience. Dr. Rainsong, who teaches university courses in music theory, models slow and deliberate observation that gives her more of an in-depth understanding of each species than I have been able to acquire so far. She also demonstrates the value of making a lot of sound recordings. Her Listening in Nature blog shares her observations, and I realize how I need to do more of this kind of work myself.

Wendy is a fine artist and art restoration specialist whose love and knowledge of nature frequently draws her into the field with her partner. She keeps her eyes open and notices many beautiful scenes, plants and animals that remind me not to be so narrowly focused. She also took the time to sit and create a couple watercolor sketches that were simply amazing. Wendy has the best ears of us three for the higher-pitched insect songs.

One of our sites was Jasper-Pulaski Fish & Wildlife Area.

A population of woodland meadow katydids provided good exposure to that dry-soil species.

A population of woodland meadow katydids provided good exposure to that dry-soil species.

This tinkling ground cricket had a darker brown head than most, but he was very cooperative, giving us many photo ops as he slowly moved across the parking lot.

This tinkling ground cricket had a darker brown head than most, but he was very cooperative, giving us many photo ops as he slowly moved across the parking lot.

Another highlight was a levee at Kingsbury Fish & Wildlife Area.

The dusky-faced meadow katydid was a priority species. We were able to observe two males.

The dusky-faced meadow katydid was a priority species. We were able to observe two males.

This Texas bush katydid, my first for LaPorte County, displayed the engaging personality of his kind.

This Texas bush katydid, my first for LaPorte County, displayed the engaging personality of his kind.

I benefited not only from observing Lisa’s and Wendy’s methods, but also picked up a total of 8 county records along the way for my study. We look forward to more exchange visits over the next few years.

 

Sound Ideas: Texas Bush Katydid

by Carl Strang

Our bush katydids, genus Scudderia, have some of the most interesting song variations of all our singing insects. They include two “counting” species, with increasing numbers of syllables over a sequence of songs. Often they have more than one song type, and this is true of today’s featured species, the Texas bush katydid S. texensis (back in the days of the Bush presidency I was fond of pointing out that there really was a Texas bush katydid).

Texas bush katydid

Texas bush katydid

The following recording includes two of the 3 song types: single clicks, which I seldom have encountered in the Chicago region, and the characteristic dusk or nighttime song, a series of quick buzzes.

During the day this species produces a very fast, 3-syllable call which I render “dig-a-dig.” It is similar to the daytime song of the broad-winged bush katydid, but the latter has more syllables (sounds like 5, usually) and they are less distinct because they have a lisping quality.

McHenry County Exploration

by Carl Strang

On Friday I took a vacation day to check out some sites in McHenry County for their singing insect potential. I saw parts of 4 widely scattered Conservation Areas (their equivalent of Forest Preserves), and picked up 4 county records for my study along the way.

Within minutes of arriving at the first site, Elizabeth Lake, I spotted this bush katydid feeding on a tansy flower head.

Within minutes of arriving at the first site, Elizabeth Lake, I spotted this bush katydid feeding on a tansy flower head.

The small body size, and the shape of the ovipositor, identified this female as a fork-tailed bush katydid.

The small body size, and the shape of the ovipositor, identified this female as a fork-tailed bush katydid.

That was not one of the county records, but I did pick up two at that site: Forbes’s tree cricket, and slender meadow katydid.

The area with the greatest potential proved to be Hickory Grove-Lyons. These areas are a political oddity. Though the Lyons portion is in Lake County, it is cut off by a bend of the Fox River, and so managed by the McHenry County Conservation District.

A boardwalk leads through a high quality marsh at Hickory Grove. Other marshes and woodlands in this, and the adjacent Lyons area, are priorities for future exploration.

A boardwalk leads through a high quality marsh at Hickory Grove. Other marshes and woodlands in this, and the adjacent Lyons area, are priorities for future exploration.

The year’s first Texas bush katydids, which also provided a county record, were singing in that marsh. The fourth county record, common true katydid (which seems oddly uncommon in McHenry), came at a good-looking forested preserve, Coral Woods. I look forward to return visits to some of these sites.

 

Encounters Along the Way

by Carl Strang

As another season of field research into the region’s singing insects winds down, I am starting to look back at the highlights. Some of these were chance encounters that provided new photo opportunities. For example, there was a weakened common true katydid I found on a trail at Waterfall Glen in broad daylight. I didn’t have a good photo of the species, and posed him after removing him from the hazardous trail.

Unfortunately I neglected to place his hind legs in a natural position.

Unfortunately I neglected to place his hind legs in a natural position.

Another species for which I want a better photo is the handsome trig. Some were singing on a cloudy day down in Fulton County, Indiana, and one came out in the open, but the low light resulted in a less than sharp image.

Tiny but colorful, the handsome trig lives in the southern part of the region I am surveying.

Tiny but colorful, the handsome trig lives in the southern part of the region I am surveying.

The Indiana Dunes area provided several photographs.

This oblong-winged katydid female was emitting single clicks in response to the more complex songs of nearby males.

This oblong-winged katydid female was emitting single clicks in response to the more complex songs of nearby males.

A four-spotted tree cricket had escaped from my grasp before I could photograph it. While looking for it on the ground where it seemed to have gone, my headlamp revealed something better.

A female tinkling ground cricket, only the second member of the species I have seen (despite hearing hundreds).

A female tinkling ground cricket, only the second member of the species I have seen (despite hearing hundreds).

A similar encounter came when I was trying to get a better photo of a melodious ground cricket at Indiana Dunes State Park. Digging through the leaf litter in the area from which a male’s song seemed to be coming, I turned up a female ground cricket.

When I examined the photos, though, I saw that the palps were white. This was a female confused ground cricket, another species that was singing in the area, and the first female confused I have seen.

When I examined the photos, though, I saw that the palps were white. This was a female confused ground cricket, another species that was singing in the area, and the first female confused I have seen.

One of the last places I visited this year was the Bong Recreation Area in Kenosha County, Wisconsin. The prairie area there is extensive, and has a good population of common meadow katydids.

Despite its name, the common meadow katydid is much less frequently encountered than two of its congeners, the gladiator and black-legged meadow katydids.

Despite its name, the common meadow katydid is much less frequently encountered than two of its congeners, the gladiator and black-legged meadow katydids.

There were a few broad-winged bush katydids in the prairie, but I wasn’t successful in stalking one. This Texas bush katydid had to substitute.

There were a few broad-winged bush katydids in the prairie, but I wasn’t successful in stalking one. This Texas bush katydid had to substitute.

Such encounters, sprinkled through the field season, make for good memories.

Literature Review: Hearing in Insects

by Carl Strang

This week’s literature review post focuses on hearing in insects. The first paper has to do with where hearing originated within the cricket-katydid group.

Stritih N, Čokl A (2012) Mating Behaviour and Vibratory Signalling in Non-Hearing Cave Crickets Reflect Primitive Communication of Ensifera. PLoS ONE 7(10): e47646. doi:10.1371/journal.pone.0047646

They looked at the group of crickets regarded as the most primitive among the living families that include the crickets and katydids. They found that vibratory behavior on tree bark is involved in courtship (the crickets emerge from caves at night), and organs on the legs that are likely homologs of cricket and katydid ears are receptors for these low-frequency vibrations. There are other insect groups today that communicate through vibrations they set up in plants. So, it apparently started with drumming the floor and feeling the vibration through their legs.

The ear is visible as a brown oval-shaped structure on the front leg of this Texas bush katydid.

The ear is visible as a brown oval-shaped structure on the front leg of this Texas bush katydid.

Of course, for hearing to be meaningful there has to be a sound production. The crickets and katydids evolved wings that buzz or chirp when rubbed together.

Gu, Jun-Jie, et al. 2012. Wing stridulation in a Jurassic katydid (Insecta, Orthoptera) produced low-pitched musical calls to attract females. Proc. Nat. Acad. Sci. U.S. http://www.pnas.org/content/109/10/3868

Abstract: “Behaviors are challenging to reconstruct for extinct species, particularly the nature and origins of acoustic communication. Here we unravel the song of Archaboilus musicus Gu, Engel and Ren sp. nov., a 165 million year old stridulating katydid. From the exceptionally preserved morphology of its stridulatory apparatus in the forewings and phylogenetic comparison with extant species, we reveal that A. musicus radiated pure-tone (musical) songs using a resonant mechanism tuned at a frequency of 6.4 kHz. Contrary to previous scenarios, musical songs were an early innovation, preceding the broad-bandwidth songs of extant katydids. Providing an accurate insight into paleoacoustic ecology, the low-frequency musical song of A. musicus was well-adapted to communication in the lightly cluttered environment of the mid-Jurassic forest produced by coniferous trees and giant ferns, suggesting that reptilian, amphibian, and mammalian insectivores could have also heard A. musicus‘ song.”

Their results with this Chinese fossil suggest a song comparable in pitch to our common species of “annual” cicadas, but with a pure tone and so, perhaps, similar in sound to a field cricket’s song but a little higher in pitch.

A final paper reported a study of the ear structure of these insects.

Montealegre-Z., Fernando, et al. 2012. Convergent evolution between insect and mammalian audition. Science 338:968-971.

They did a micro-anatomical and functional study of a rainforest katydid’s ears, and found that the external membrane on the leg is connected by a lever system to a fluid-filled chamber where the sensory cells are stimulated. These components within the insect’s leg are analogous to the structures in our ears.

Bioblitz Incidentals

by Carl Strang

While my main focus at the Kankakee Sands bioblitz was on observing singing insects, I also was noting other species along the way, and was interested in others’ observations of singing insects. Someone in the Purdue entomology group collected a female bush katydid, for example.

The ovipositor marks it as female, the wing proportions and head shape place it among the bush katydids (genus Scudderia).

Female bush katydids are tricky, but I’m pretty confident that this is a Texas bush katydid. The sharp bend in the ovipositor, especially the inward or upper edge, narrows it down to a very few species. A broad-winged bush katydid would have broader wings, and a fork-tailed bush katydid would have a reddish-brown rather than green ovipositor. The colors and shapes of other structures around the ovipositor, and the shape of the ovipositor itself, match those of the Texas bush katydid, which is a common species of prairies like the one where this insect was collected. I didn’t hear any singing, but in DuPage County these tend to start up later in the season.

I saw a number of little yellow butterflies that had the markings of sulphurs but were unfamiliar to me.

The little sulphur is a species associated with sandy soils, and so unlikely to turn up in my familiar DuPage County haunts.

A milkweed leaf beetle turned up in a sweep sample in one of the prairie areas.

Like so many other milkweed feeders, this species has colors of black and orange.

Alyssa noted that I had picked up a hitchhiker at one point.

This proved to be Henry’s marsh moth, a noctuid of wetlands with a broad larval diet.

One of our nets caught an impressive jumping spider.

It was a big one, marked by a white stripe across the abdomen.

Finally, I photographed a grasshopper nymph that I thought might belong to a stridulating species, but I think it is in the wrong group.

I heard a grasshopper stridulating, but never saw it, and was only guessing here.

Grasshoppers are a group I usually will need to collect for identification.

Wings Flash

by Carl Strang

I was finishing a bike workout, pedaling the final blocks toward home, when a large insect flew across my path. Green, and with wings and legs widely spread, it gave me the split-second first impression was that I was seeing a praying mantis. But the wings were wrong, proportions were wrong, and it didn’t have the Edward Gorey weirdness of a mantis’ profile in flight. The insect turned around, flew back across the street, and crash landed on a lawn. I stopped, dug out the phone, and used it to photograph what I now realized was a greater anglewing.

The spread of that katydid’s wings in flight reminded me of another recent observation. I have taken opportunities to watch a few Texas bush katydids singing, and have been struck by how much the wings flip out to the sides, especially when compared to the more subtle vibrations of singing meadow katydids. I suspect I may be onto what made the Texas bush katydid I observed at Pratts Wayne Woods have such a slurred short-song, with a quality reminiscent of the broad-winged bush katydid’s corresponding advertisement. Here’s another shot of the Pratts Wayne katydid.

It’s missing a wing tip, and there also was scarring near the base of the left forewing. Such damage may well have caused the dramatically flipping wings to sound abnormal when rubbing together to produce the song. The typical crispness that would come from, say, this undamaged conspecific I saw in the dolomite prairie at Waterfall Glen, is compromised.

By the same token, the broad-winged bush katydid’s wings are shorter and wider, and might be expected to flop around more, so that the slurring typical of that species’ short song results. Experimental manipulations suggest themselves, but I’m not interested in captive studies at present.

Pratts Wayne Woods

by Carl Strang

Pratts Wayne Woods is the largest of DuPage County’s forest preserves. While its 3500 acres have much to offer, the target of my most recent visit was the Brewster Creek Marsh. I had a couple species of meadow katydids in mind that I especially hoped to find there. The part of that marsh I was surveying was adjacent to a dry area where there are high-level equestrian jumping competitions. As I passed through part of that meadow I heard a bush cricket’s short song. It took some minutes to find him, as he took advantage of the light wind moving his perch to keep an edge toward me.

His song was a little ambiguous. I have come to think of the broad-winged bush katydid’s short song as sounding blurred, run together, and composed of more than 3 syllables. The Texas bush katydid usually has a three-syllable short song that sounds, to my ear, crisp and articulated: dig-a-dig! I needed to take the time to find this individual because his short song had 3 syllables but sounded slurred together.

The wing proportions alone say Texas bush katydid, but to be sure I caught him and photographed his tail plate, confirming the ID. Now it seems I will have to find a few more and confirm that it’s the syllable count rather than the crispness that matters in separating these two species. Soon thereafter I found myself in a wet area dense with tall sedges in northern Brewster Creek Marsh.

It was disappointing, however. There was essentially nothing to be found out in the sedge area, and just a few black-legged and short-winged meadow katydids singing along the edge. I moved west to a grassy area at the edge of a large pond. As I stepped out of the woods into that grass I caught a flash of golden brown as a slender jumper got out of my way. My immediate hope was fulfilled when a close look proved the insect to be one of my target species, a male black-sided meadow katydid.

This was the best photo I got of a male. The abdomen is mainly a shiny black in color. I saw several males, and also a female.

She easily is the most colorful small meadow katydid I have seen, and would vie with the male black-leg (a large meadow katydid) as the local show winners for subfamily Conocephalinae.

Fork-tailed Bush Katydid

by Carl Strang

Earlier this week I encountered a katydid on the concrete drive near the friary at Mayslake Forest Preserve.

Its wing and head shape placed it among the bush katydids. It was too small for a Texas bush katydid, and its wings were too narrow for a broad-winged. To identify it I had to catch it and photograph the tip of its abdomen. I was rewarded with a surprisingly sharp nip on the finger which, though it grabbed my attention, didn’t even break the skin.

The distinctive shape of the gray structure gives this insect its common name. I had photographed one a few years earlier, at Fullersburg Woods.

Though references say these katydids frequent bushes and herbaceous growth as well as trees, in my limited experience this is a tree-dwelling species in northeast Illinois. Its song is a bit of a challenge, being typically a single quick lisping rasp of the wings that, to my ear, is not much different from the alternate song of the greater angle-winged katydid. The only suggestion I have seen that promises a solution to this difficulty is in the instructions for the New York Cricket Crawl. They suggest that this sound is produced only once every few minutes by the greater angle-wing, while the fork-tailed calls several times a minute. I suppose until I have reason to believe otherwise, or can learn to distinguish the two, I shall have to follow this demarcation.

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