Closing the Book on Green-winged Cicadas

by Carl Strang

The green-winged cicada (Diceroprocta vitripennis) provides a favorite example of why I need to include 22 counties in my survey of Chicago-region singing insects. I checked a final two locations recently, and am satisfied that I have a good sense of where this species occurs.

Black dots indicate counties where green-winged cicadas can be found.

The most important habitat feature appears to be sandy soil. Cicadas spend most of their lives underground, so it is not surprising that soil texture can influence their distribution. The mapped area contains two sandy regions: the dunes edge of Lake Michigan in Indiana and Michigan, and the Kankakee River corridor. The cicadas do not, however, extend throughout those soil areas. They thin out quickly in western Starke and Pulaski Counties, Indiana, and do not reach into the sand soil portions of St. Joseph and Marshall Counties.

Green-winged cicadas had an important lesson for me this year. Previously I had thought of them as a woodland species, having observed them singing in trees, especially in black oak savannas and woodlands. Then I came to this spot in Newton County, Indiana:

A single large cottonwood and two smaller trees towered above clusters of shrubs.

I was surprised to step out of the car, expecting to focus on sand-soil grasshoppers, and hear green-winged cicadas singing. As I approached them I found that they were singing, not from the big trees, but from plants no taller than me, winged sumacs and a small black oak.

This discovery provided a welcome opportunity to photograph live green-winged cicadas.

They were very alert, and required a glacially slow stalk.

Feel free to wave back. No one is watching.

I also found a site in Jasper County where the cicadas were singing from shrubs. They can be fairly loud at close range, but they are small, with bodies not much more than an inch long, so the song quickly attenuates over distance. It seems to carry better when the singing perch is in a tree. The song is a distinctive pulsing rasp:

These early season cicadas sing mornings to mid-afternoons, and largely are done by the end of July.

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Southern Lessons

by Carl Strang

This year’s chapter in the series of annual bioblitzes organized by the Indiana Academy of Sciences took place at Eagle Creek Park in northern Indianapolis on June 2-3. This is early enough in the season that there were few singing insects for me to find, but I was able to gain valuable experience with two southern species that occur or have occurred in the Chicago region.

The first of these is the spring trig.

Female spring trig at Eagle Creek.

This species of tiny cricket first was described in 2014. That is surprising, given its abundance in southern Indiana and its extensive range beyond the state. It proved to be common in a range of habitats at Eagle Creek Park, from woodland edges to grassy meadows.

Spring trigs appear plain-faced to the eye, but bright light and magnification reveal a pattern of fine dark lines.

I learned more about the spring trig’s habitat, and found that I can hear them easily while driving at speeds of 30mph or less. This allowed me to get clarity on the species in the Chicago region. Driving in the southernmost counties, I found widely scattered small colonies in Fulton and Jasper counties, at road edges where wider bands of herbaceous plants were backed by woodlands. In the future I expect to find them in southern Pulaski and Newton counties, too, but not north of there.

Eagle Creek Park also has a large population of northern wood crickets.

The northern wood cricket is a forest species that is smaller and blacker than the spring field cricket, which could be heard chirping in the park’s meadow areas.

The spring field cricket is a few millimeters longer, typically has bronzy wings, and has a proportionately broader head and thorax.

Recordings I made during the bioblitz, and at home with a captive male, have provided further clarity on northern wood cricket song characteristics. Their chirps may never have 4 pulses (commonly 2 or 3), and almost never rise above 5 kHz in pitch, where spring field crickets often have 4-pulse chirps, and seldom drop below 5 kHz. Habitat also helps separate the two. I dug deeper into the literature, and learned more about historical records of the species in two Chicago region counties. Those observations were made in 1902, and I went to the sites in the weeks after the bioblitz. Northern wood crickets no longer occur there. I believe the records are correct, but that the crickets have gone extinct in those places. Northern wood crickets are reported to be sensitive to forest fragmentation, perhaps especially so in the northern fringe of their range, and such fragmentation clearly took place where they once were found in Lake and Marshall counties. I will continue to check the region’s larger surviving forest blocks, but it seems likely that the species no longer occurs in northern Indiana.

Incidentally, the other expected early-season singing insect, the green-striped grasshopper, lives in Eagle Creek Park’s meadows and prairie areas.

Next year’s bioblitz is expected to take place in one of my counties, and I am looking forward to the experience.

 

A Good Burn

by Carl Strang

The Forest Preserve District of DuPage County has invested a welcome amount of effort in restoring the forest at St. James Farm, where I am volunteer steward. Early this spring a large group of trained staff came in and conducted a successful burn of accumulated leaf litter in the main part of the forest. The point of the burn is to kill or at least weaken invasive plants such as garlic mustard and barberry.

The contrast between the unburned trail and the burn area reveals the intensity of the burn.

The burn coverage was about as complete as one could expect.

No burn is complete, however. Some forest floor invertebrate species will need a few years to recover, but there will be plenty surviving in small spots missed by the fire, as well as surrounding areas not included in the burn.

A smaller burn on an earlier date in the area we are clearing of buckthorn was not as complete, because the leaf litter accumulation was relatively shallow and spotty.

I didn’t take any photos of the main burn as it was taking place because I was busy. Our forests historically burned very infrequently, and some of the plants cannot be assumed to be as fire-adapted as the ones characteristic of savannas and woodlands. In particular I was concerned that blackhaws (Viburnum prunifolium), the dominant shrub layer species, might be harmed. So, I worked ahead of the flames, frantically raking dead leaves away from the bases of as many blackhaws as I could reach in the two hours that I had. I did not have time to cover the entire forest, so there were some areas where the flames reached the bases of blackhaw shrubs.

Some blackhaws were heavily scorched.

Other blackhaws were lightly scorched.

Blackhaws I cleared by raking away the leaf litter were unscorched.

In subsequent weeks the forest leafed out, and the blackhaws bloomed.

Blackhaw flower cluster

I spent part of an afternoon assessing scorched vs. unscorched blackhaws. The scorched ones nearly all had plenty of leaves, though a few were killed. Most scorched plants had some flowers, though almost all were limited to 1-5 clusters.

Unscorched blackhaws had abundant flower clusters.

A little less than two-thirds of the scorched shrubs flowered at all, and again, those that did had few. Nine-tenths of the raked blackhaws bloomed, for the most part with many more flower clusters. Sample sizes were large enough to support a strong statistically significant difference. I will continue to watch this, as I am concerned that the scorched plants may have been partly girdled by the flames. I will be recommending that other forest stewards take measures to work with the fire crews and protect the native shrub layer of our woodlands by raking away fuel from shrub bases.

In the meantime, the part of the forest that we have been clearing of buckthorn and other invasive shrubs is showing first fruits of our efforts.

Even in this first year, our treatment area showed an encouraging growth of spring ephemeral herbaceous plants.

One long-term goal will be to promote blackhaw and other native species, so as to restore the shrub layer in the area we have cleared.

Wood Be? Wouldn’t Be!

by Carl Strang

For a couple years now, I have been pursuing early-season crickets that I thought must be northern wood crickets (Gryllus vernalis). These close relatives of our familiar spring field crickets (Gryllus pennsylvanicus) had been reported to occur in two of the counties in the Chicago region, both in northern Indiana. Spring field crickets are abundant in well-drained open grassy areas in my home county of DuPage, in Illinois. When I started hearing chirping Gryllus songs in Indiana woodlands and savannas, coming from accumulations of oak leaves often under trees, I figured these must be wood crickets.

For example, my attention was drawn to clumps of oak leaves surrounded by sand, along the Marquette Trail in the Indiana Dunes National Lakeshore. Nothing grassy about this!

A few days ago, I headed to the Marquette Trail to make another attempt to see one of these crickets. I wanted to confirm my suspicion, but also to get photos of a living northern wood cricket.

All I had were photos of museum specimens like this. Note the taper from the back of the thorax through the head. Spring field crickets are broader in front.

As I walked along a section of trail beside a road, I heard one of the crickets singing in a narrow band of accumulated oak leaves at the base of a hill.

An earlier controlled burn had removed nearly all the available cover. Puccoons bloomed magnificently above the line of leaves.

I made a sound recording of the singing cricket, and used the shotgun microphone to get his exact location. Then I lifted the layers of leaves to see if I could spot him.

You may be able to see the tunnels in the sand. At first I figured he made a quick retreat into them when I lifted the leaves.

If you look in the lower right-hand corner of the photo, however, you may see a small oval of reflected light. After taking the picture I discovered it was the cricket! I got him into a plastic cup.

I got my photos, and did my best to make him a northern wood cricket, but in fact he was a spring field cricket. Not only were his proportions wrong, but he held still and let me hold calipers just above him for a measurement. Spring field crickets usually are 16mm long, northern wood crickets 14mm, and this one was 16.8mm.

After reviewing my recordings, I think all the woodland Gryllus crickets I have heard in the region in fact are spring field crickets. There were small technical differences in song parameters between crickets in tree leaves and those in grassy areas, but I have to conclude that they don’t represent a species difference. The lesson ultimately is one of habitat. Spring field crickets on clay soils occur only in well-drained grasses. In sandy areas they broaden their habitat into woodland edges, and don’t associate strictly with grasses.

Further review of reference recordings points me toward northern wood crickets having more rapid chirping speed, and a lower pitch, resulting in a slightly less musical impression. So it’s back to square one for northern wood crickets in the region, and my insistence on visual confirmation of suspected but ambiguous species observations is vindicated.

Bird Feeder Lessons

by Carl Strang

Except for my yard, my neighborhood contains mainly lawns and some foundation shrubs, along with the small trees planted to replace the near monoculture of ashes killed by emerald ash borers. My own plantings had grown to the point where I thought they might provide enough cover to make it worthwhile to put out bird feeders.

I hung a tube feeder above a platform feeder set on the ground. Through most of the winter, safflower seeds were the main fare.

One day I saw a meadow vole popping out from the snow to grab one seed at a time from the platform.

Its main residence appeared to be beneath the inverted water garden container, but underneath the platform feeder it also had excavated a network of tunnels.

Most birds were infrequent visitors. The regulars were a small flock of mourning doves. They are not limited to small winter territories, and their longer distance patrols allow them to find scattered food sources. I hosted up to 20 of them in the early mornings, and 3 or so at dusk.

Eight or so of “the troops,” as I came to call them, are visible in this blurry photo through the kitchen window.

After the morning feed, they often rested a bit before moving on.

One dove that came at mid-day gave a demonstration of limited intelligence.

It happened to land inside the little decorative fence that surrounds the water garden. Reaching through the bars, it fed for a bit but then appeared to become frustrated.

The bird walked back and forth for a good ten minutes, sticking its head through various holes but unable to reach the seeds it wanted. It never figured out that all it had to do was go over the little fence and stand in the feeder to take all the seeds it wanted.

Eventually the dove decided to leave, and jumped up to perch on the fence before heading on its way.

 

St. James Farm Update

by Carl Strang

It has been a while since I have written about St. James Farm, where I volunteer as forest steward and monitor. There has not been a lot to report, in part because foot problems have limited my monitoring activity.

Going back to last fall, I noted that the patches of invasive goutweed where we dumped garlic mustard showed a difference. One patch, which had not been hit by herbicide in the spring, pushed its way through the mounds of wilting garlic mustard and was barely slowed.

Other patches like this one, which forest preserve district staff had sprayed earlier in the spring, appeared to be inhibited further by the dumps.

I noted that goutweed does not maintain winter rosettes, but withdraws nutrients into the roots and shuts down the leaves, growing new ones in the spring. This coming fall I plan to hit experimental patches of goutweed with herbicide, with the idea that I might find an optimal time when the poison, drawn down along with the conserved nutrients, will do the most damage to those invasive plants.

Through the winter I took series of monitoring walks twice a month. There was little that was new.

Predators took their tithe, in this case pulled feathers spoke of a male eastern bluebird caught by a raptor.

This buck was one of a group of three that occupied the western part of the forest through the winter.

Though I cut back on monitoring efforts, Wednesday morning restoration activity continued. Our focus through the winter consisted of cutting and stacking common buckthorn, then burning the piles.

Our earlier cutting accumulated 17 piles like this.

Burning them leaves relatively small scars, but the soil is sterilized. I will be interested in seeing what plants invade these little spaces.

Already we have built several new piles. There won’t be enough snow to allow any more burning now, but by next winter there will be plenty to torch.

My feet are under treatment, and I expect to return to full activity soon.

 

Singing Insects Guide 2018

by Carl Strang

The general summary of my singing insects research is a 116-page guide, Singing Insects of the Chicago Region. It contains photos, maps, links to song recordings, and information with a page for each species. It is available for free as a 5-6mb PDF document, sent as an e-mail attachment.

This Texas bush katydid continues as the cover photo.

If you are on the mailing list, you should have received the updated version earlier this month. To get a copy and get on the list for annual updates, send me a request at wildlifer@aol.com

This year’s version is expanded significantly, as I created pages for species which occurred historically in the region but which I have not yet found. I also added photos of museum specimens in cases where I have no photos of live insects, and have a new page for the eastern striped cricket, which I found for the first time in 2017. Already I know that I will need to add a page in next year’s version, as Nancy Collins has sent me documentation of a 2005 find of tamarack tree crickets in Berrien County.

The long-term plan is to continue this annual updating through 2024, when periodical cicadas have their next major emergence in the region. Then I will see about getting a print version made. In the meantime, if you have need for a higher-resolution photo than the compressed (but adequate, I think) versions in the guide, send a request to that same e-mail address.

Pilot Mountain

by Carl Strang

On the way to visit my brother and his family in eastern North Carolina for Christmas, I made a stop at Pilot Mountain State Park in the western part of that state. Pilot Mountain is an isolated peak that rises 1500 feet above the surrounding terrain (against only 2 miles’ diameter at the base), and its striking profile is visible from miles away in all directions. My route takes me right past it, and a quick entry is available from that interstate highway.

There are two high points, and you can drive to the top of the lower of those.

This view from the top gives a sense of Pilot Mountain’s dramatic rise.

The sides of this quartzite-cored peak are forested. White, red and chestnut oaks were the dominant trees in the part of the forest I explored.

A nice network of trails wraps around the park.

As a biologist, I was especially interested in the wildlife.

The deer and the gray squirrels looked small as compared to those in northern Illinois. This probably is a latitude effect rather than a peculiarity of the park.

My eyes scanned the trail from time to time, and I was pleased to see some bobcat tracks, but those were dwarfed by a few footprints that had been made by something much larger.

This was the clearest example. At 3-4 inches in diameter, with a circular overall outline and lacking toenail marks, it was close to mountain lion tracks I have seen out West.

Here is an example from Big Bend National Park, Texas.

I passed on my observation to the park staff. A little internet searching revealed that the presence of mountain lions in western North Carolina is debated. I believe my identification is correct, but this does not mean that there is a resident population with Pilot Mountain in a lion’s home range. Our experience in the Midwest is that mountain lions have been wandering outward from the Black Hills, several states away. One was killed in Chicago a few years ago. These cats, though big, are wary and capable of staying out of sight. I would not be surprised at all if eventually it is established that the mountainous region of western North Carolina and surrounding states harbors a resident population of this large predator.

 

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.

 

Psorting Out Psinidia

by Carl Strang

This year I found longhorn band-winged grasshoppers (Psinidia fenestralis) in Newton County, Indiana, Kenosha County in Wisconsin, and Lake and Cook Counties in Illinois. Previously I had found them in Porter and Marshall Counties, Indiana.

Longhorn band-winged grasshoppers are named for their disproportionately long antennae.

The hind wings of these small grasshoppers usually are bright red.

Two of the newly found populations raised questions. First, at Burnham Prairie in Cook County, they had bright yellow hind wings, in place of the usual red.

I learned that yellow hind wings are known to appear occasionally in the species.

Then I found red-winged ones in the same spot at Illinois Beach State Park where I found insects I had identified as Kiowa rangeland grasshoppers (Trachyrhachys kiowa) in 2014.

That original identification was based on one individual I captured with this wing pattern.

Kiowa rangeland grasshoppers typically have transparent bases in their hind wings, but these can be pale yellow. That fit my photos, and there are historical records for Lake County, Illinois, so I felt that my identification was correct. Now, poring over references and my photos, and going back and forth in my conclusions, I have decided that the 2014 grasshoppers in fact were Psinidia, and the individual I caught was an unusual one with transparent hind wings. The antennae had flattened bases and were as long as the hind femurs, like Psinidia but unlike T. kiowa, which have shorter, finer, rounder antennae. The hind tibias were largely bluish, but had black bands, then yellow, then black at their proximal ends, like Psinidia. Reference photos for kiowa show blue tibias interrupted by yellow bands toward the proximal ends, but no black.

Confusion between these two species is understandable: both are small, and both have heads that protrude above their thoraxes. Unfortunately, this removes the only present-day record I had for Kiowa rangeland grasshoppers in the Chicago region. I still hope to find them, because historical records place them not only in Lake County, Illinois, but also Will County, and Lake, Newton, and Jasper Counties in Indiana.

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