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.

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A Mystery Solved: Miogryllus!

by Carl Strang

In 2014 I first heard what sounded to my ear like a singing striped ground cricket, but it seemed too early in the season. It was June 21, at Hoosier Prairie Nature Preserve in Lake County, Indiana. I made a recording, then moved on to the Indiana Kankakee Sands, where I heard it again. Though these sites are a bit south of my DuPage County home, I didn’t hear striped ground crickets in DuPage until July 13. The next year I heard the same odd songs, this time at the Midewin National Tallgrass Prairie, in the middle of Will County, immediately south of DuPage. This was even earlier, on June 10. Again I made a recording. And again, I did not hear striped ground crickets in DuPage until, as it happened, July 13. In 2016 I went down to Midewin on June 28, and heard the same early, striped-ground-cricket like songs. This year, the same story, Midewin, June 23. This time, though, it seemed to me that the songs were not quite right for striped ground crickets. They seemed too precise, too even and strong. Here is a recording I made in the same location on June 28:

I went back and listened to my earlier recordings, reviewed my list of hypothetical singing insect species for the Chicago region, then checked reference recordings of their songs. The early songs did sound different from my recordings of later-season striped ground crickets, an example here:

The odd, early songs seemed to be a match for one of the hypotheticals, the eastern striped cricket, Miogryllus verticalis. Furthermore, references indicated that M. verticalis is an early season species, most abundant in June. I drove back down to Midewin on June 28. Trying to zero in on the singers was very frustrating; they seemed to have a ventriloquial quality. Eventually I flushed out and captured a female cricket near one of the singing mystery males. Looking through the clear plastic cup that held her, I could see that she was indeed an eastern striped cricket. I took a couple photos looking down into the cup. It was well that I did, because when I tried to get her positioned for a shot from the side, she gave me the slip and I was unable to recapture her.

Female eastern striped cricket, dorsal view

She was just a little smaller than a spring field cricket, which species was sharing the grassy meadow where Miogryllus were abundant. This confirms that eastern striped crickets are established in the southwestern portion of the 22-county area I define as the Chicago region. They would seem to represent yet another example of a range extension northward by a singing insect species.

Making a Case 3: Northern Wood Cricket

by Carl Strang

Last year I concluded that I had found northern wood crickets (Gryllus vernalis) in the Winamac State Fish & Wildlife Area in Pulaski County on June 13, based on habitat and sound recordings. In 2016 I returned to that site on May 29, but did not find them singing. On June 3 I heard Gryllus crickets chirping along the Marquette Trail, near the east border of Lake County, Indiana. All were in forest or savanna areas, the singers in deeply layered black oak leaves, usually in shade under black oak trees but some in isolated collections of leaves surrounded by sand.

One of the woodland crickets’ song sites near the Marquette Trail.

One of the woodland crickets’ song sites near the Marquette Trail.

None were in the open grassy areas favored by spring field crickets (G. veletis), even though such habitat was close by. I recorded two of these individuals, and later in the season recorded field crickets in meadow and prairie habitats favored by veletis but where vernalis would not be expected, plus another individual that by habitat should be vernalis, at the Kankakee Sands site in Kankakee County, Illinois.

The results seemed contrary to what would be expected from previous studies.

The likely vernalis (forest) had lower chirp rates than likely veletis (grassland).

The likely vernalis (forest) had lower chirp rates than likely veletis (grassland).

The number of pulses per chirp was unhelpful, with likely veletis ranging 2-4, likely vernalis 3-4. Linear regressions of the two sets of data show, perhaps significantly, the same slopes of chirp rate increase with temperature (physiology of closely related species expected to show a similar response to temperature). The linear regressions indicate that, for a given temperature, forest cricket chirp rates are 1.44/second less than grassland chirp rates. All data I can find in the literature for vernalis were collected from that part of their range where they are sympatric with the southern wood cricket (G. fultoni). Jang and Gerhardt (2005. J. Evol. Biol. 19:459–472) found that fultoni song characteristics differed between populations sympatric with vernalis and those allopatric to that species. They did not study allopatric vernalis. As my recordings may be the only ones that have been made where vernalis is allopatric to fultoni, and given the clear difference between recordings in habitats for likely vernalis and likely veletis described above, so far it appears that habitat, chirp rates and temperatures will be enough to establish the presence of vernalis. The major obstacle to finalizing this conclusion is confirming the identity of the forest crickets. So far I have been unsuccessful in efforts to catch or even see one. Next year I need to continue making recordings and trying to catch and measure suspected northern wood crickets.

Short-winged Toothpick Grasshopper

by Carl Strang

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.

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.

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.

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.

Illinois’ Kankakee Sands

by Carl Strang

In the Chicago region when someone mentions the Kankakee Sands, usually they are referring to the Nature Conservancy project in Newton County, Indiana. There is, however, a nature preserve in southeastern Kankakee County, Illinois, also known as “Kankakee Sands,” which also is worth knowing about.

The preserve has very high quality oak savanna and prairie ecosystems.

The preserve has very high quality oak savanna and prairie ecosystems.

I paid my first visit to this site on Friday, and left with a good dozen singing insect county records.

Most species were sand-soil singers I had encountered before, but this was my first sprinkled grasshopper.

Most species were sand-soil singers I had encountered before, but this was my first sprinkled grasshopper.

He was buried in a grass clump, offering no chance of a good photo. Fortunately he was open to climbing onto my finger for a portrait. The all-black pronotum sides are unique.

The most common orthopterans were tinkling ground crickets and straight-lanced meadow katydids, unsurprising on this sand soil.

One of the many male straight-lanceds from Friday.

One of the many male straight-lanceds from Friday.

I was pleased also to find that my new friend the handsome grasshopper is common there.

Handsome grasshopper, male.

Handsome grasshopper, male.

Female handsome grasshoppers were a bit bigger and green rather than brown.

Female handsome grasshoppers were a bit bigger and green rather than brown.

Both mottled sand grasshoppers and Boll’s grasshoppers also were there, the former often punctuating the scenery with their bright yellow hind wings in flight.

Boll’s grasshopper also has yellow hind wings. These are concealed when both species are at rest.

Boll’s grasshopper also has yellow hind wings. These are concealed when both species are at rest.

There also were plenty of bush katydids.

Most were curve-tailed bush katydids.

Most were curve-tailed bush katydids.

One, slightly smaller, proved to be a male fork-tailed bush katydid.

One, slightly smaller, proved to be a male fork-tailed bush katydid.

Kankakee Sands are worth a visit on either side of the state line.

 

A Night Excursion to Kankakee Sands

by Carl Strang

Kankakee Sands is a Nature Conservancy site in Newton County, Indiana. Except for the early-season bioblitz there a few years ago, my visits have been in the daytime. Last week I made a nighttime trip to Kankakee Sands. This netted several new species observations for the county as well as the site, the best of which was a grasshopper I had not encountered before.

The handsome grasshopper is well named. A spindly little guy, he was rather jumpy after I caught him in the grasses and released him on the gravel parking lot.

The handsome grasshopper is well named. A spindly little guy, he was rather jumpy after I caught him in the grasses and released him on the gravel parking lot.

All of that was incidental to my main goal, however, which was to continue my collaboration with Gideon Ney of the University of Missouri. Gideon’s lab, led by Johannes Schul, is working out the evolutionary history and relationships of the conehead katydids, genus Neoconocephalus. Two of them, the robust conehead and the false robust conehead, are sibling species reliably separated mainly by differences in their songs.

Robust conehead…or is it?

Robust conehead…or is it?

I stopped at several locations, recording singing males and then trying to catch them. I need practice. They were quick to stop singing as I approached. Ultimately I was able to accumulate 12 recordings, catching the males producing 6 of them.

Here they are, ready to be packed for overnight shipping along with the recordings.

Here they are, ready to be packed for overnight shipping along with the recordings.

A couple of the songs seemed different to my ear, so I am hopeful that the effort will result in a mix of the two species, and an education on what to look for in sonographs of the recordings so I don’t have to capture them in the other counties of my survey region.

Recent Photos

by Carl Strang

Time to bring out a backlog of photos from the first half of August. First, a couple bumble bees from my last day on the job at Mayslake Forest Preserve.

This Bombus auricomus was huge, practically dwarfing the carpenter bees working nearby. She must have been a new queen, stocking up for her long winter wait.

This Bombus auricomus was huge, practically dwarfing the carpenter bees working nearby. She must have been a new queen, stocking up for her long winter wait.

Nearby, this yellow bumble bee Bombus fervidus also worked the wild bergamot.

Nearby, this yellow bumble bee Bombus fervidus also worked the wild bergamot.

The remaining photos are from a few days’ bouncing around in singing insect surveys.

This oblong-winged katydid peeked out through a hole in the vegetation in the late dusk at Midewin National Tallgrass Prairie.

This oblong-winged katydid peeked out through a hole in the vegetation in the late dusk at Midewin National Tallgrass Prairie.

This mottled sand grasshopper at Kankakee Sands was my first for Newton County, Indiana.

This mottled sand grasshopper at Kankakee Sands was my first for Newton County, Indiana.

Female Carolina ground crickets are distinctive with their short ovipositors. This one posed at Subat Forest Preserve, Kendall County.

Female Carolina ground crickets are distinctive with their short ovipositors. This one posed at Subat Forest Preserve, Kendall County.

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.

Robust Conehead

by Carl Strang

One of the target species this year in my singing insects study was the robust conehead, a large katydid. It had proven to be absent from DuPage County, though the entire region is included in range maps for the species, and Richard Alexander had reported that he collected one in southern DuPage decades ago. Last year I concluded from my literature review that it primarily is a species of sandy soil areas, at least in the northeast Illinois-northwest Indiana region. As I drove the roads after dark in the Kankakee Sands bioblitz, I quickly found robust coneheads to be common.

Male robust conehead, wings elevated into singing position.

Their song is indeed as loud as the literature suggests. Like those of some other conehead species, it is a high-pitched continuous buzz, but it is so loud that it carries a long distance, and up close its volume is amazing. If a clincher is needed, the color of the cone provides it.

The underside of the cone at the tip of the head has no black area, though reportedly sometimes there is a narrow dark line at the end.

Robust coneheads generally occurred in tall dense herbaceous vegetation in open areas. On occasion this included narrow roadside strips backed by woodlands, though such sites were never far from more extensive openings.

Straight-lanced Meadow Katydid

by Carl Strang

The Kankakee Sands bioblitz gave me the opportunity to learn more about the straight-lanced meadow katydid. My only certain identification in northeast Illinois was a male in Kane County last year. I had photographed some females with long ovipositors, but most of these seemed better fits as short-winged meadow katydids. An open area at the Conrad Savanna State Nature Preserve proved to have an abundance of straight-lanced, and they were the only members of their genus (Conocephalus) in that location.

This was a dry sandy-soil spot with grasses, whorled milkweed, hoary vervain, and a Lespedeza species as the major plants.

Mature females left no doubt.

The ovipositor length consistently exceeded the insects’ body length. Some of the literature I had seen had given femur length as the measure, but my experience in northeast Illinois had given me doubts.

Late-instar female nymphs likewise had exaggerated ovipositors.

In this one the ovipositor is much longer than the body.

Though I could hear the incessant buzzing, free of ticks typical of meadow katydid songs, that supposedly marks the straight-lanced song (using the SongFinder, of course), searching and sweep sampling produced just a single male, a nymph in the penultimate instar.

Already the cerci are showing extended flattened tips that will be even longer at maturity. They are long enough here to be diagnostic, I think.

I was paying attention to femur color patterns as well. Note the diffuse blackish stripe on the male nymph. I think this will prove to be diagnostic, when present. It is lacking in the mature female in the first photo, however. From this experience I am inclined to regard body length rather than femur length as the measure the ovipositor needs to exceed on a mature female meadow katydid to be considered a straight-lanced. Going back through my photo records, I found only one that met this criterion.

This one I caught in the dolomite prairie at Waterfall Glen Forest Preserve in 2010. Note the blackish stripe on the femur.

This was one of the two highlights of my singing insect survey at the bioblitz. I’ll share the other in my next post.

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