The Currency I Work in

by Carl Strang

The main focus of my research these days is traveling through the 22 counties of my survey area, seeking the singing insects that live in the Chicago region. I am building on previous years’ work, filling gaps in range maps. The currency I work in thus is county records. There are around 100 species known to have occurred here, and so the maximum total would be 2200 county records. This is not going to be the eventual result, however, because many of the species live only in limited areas within the region. For instance, last week I closed the book on the green-winged cicada.

This distant photo is the best I have so far of a green-winged cicada.

This distant photo is the best I have so far of a green-winged cicada.

I do not expect to find green-winged cicadas beyond the 10 marked counties.

I do not expect to find green-winged cicadas beyond the 10 marked counties.

They occur only in sand soil woodlands within the region. Though other counties have some areas with sand soils, I have searched them and failed to find the species. Their numbers clearly diminish at the periphery of their range. Four of these county records have been from this year.

Other species are widespread, and ultimately I expect to find them in every county. Two early season species now have filled maps as a result of my travels this spring and early summer: Roesel’s katydid, and gladiator meadow katydid.

Roesel’s katydid

Roesel’s katydid

There is learning involved in the process. Some species which historically have occurred in the area I have not yet found. Others I have found once or twice. At some point I become familiar enough with a species that I know how to find it. Then I seek it out in the appropriate habitat in the counties where I haven’t found it. The sulfur-winged grasshopper is an instructive example. This year I made a push to complete the map for this early-season species. Though I ran out of time before the end of its season, I got close.

Updated map for sulfur-winged grasshopper

Updated map for sulfur-winged grasshopper (open circles represent historical records)

Next year I will check sandy sites in two of the counties in Wisconsin, LaPorte County in Indiana, and Berrien County in Michigan. Though I suspect that sulfur-winged grasshoppers occur in every county, they are very few and hard to find away from sand soils. Though my own county of DuPage is marked, it is a clay soil county and over the many years I have lived here I have encountered fewer than 5 sulfur-wings in DuPage.

A final example is the northern bush katydid. I had heard two of these in the early summer of 2007, in woodlands in my county. I had heard none since. But a few days ago I went back to one of those sites and tried listening at night with the SongFinder, a device which reduces the pitch of sounds. Lo and behold, I discovered that Parson’s Grove at Danada Forest Preserve has a lot of northern bush katydids. I hadn’t realized that it was the deterioration of my hearing with age that had prevented my detecting them. Now I anticipate finding them in every county in the region.

So far this year I have accumulated 47 county records. I expect to end up with more than last year’s 174.

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.

Recent Travels: Singing Insects

by Carl Strang

Though my main research focus is singing insects, I don’t end up photographing them much, as I am listening for them rather than looking for them. Sulfur-winged grasshoppers continued to be an early-season focus.

Though I added several more county records for the species, there was not additional range in their color variation. This female was at Cook County’s Bluff Spring Fen.

Though I added several more county records for the species, there was not additional range in their color variation. This female was at Cook County’s Bluff Spring Fen.

Here is a typical dark male, Illinois Beach State Park.

Here is a typical dark male, Illinois Beach State Park.

Not much different, this male was around the corner of Lake Michigan at Indiana Dunes National Lakeshore.

Not much different, this male was around the corner of Lake Michigan at Indiana Dunes National Lakeshore.

Only 8 species of singing insects could be found at Goose Pond. There will be many more there later in the season.

Green-striped grasshoppers still were displaying, but their days are numbered.

Green-striped grasshoppers still were displaying, but their days are numbered.

Spring field crickets seldom come into view. This female was a challenge to photograph as she crawled among the grasses.

Spring field crickets seldom come into view. This female was a challenge to photograph as she crawled among the grasses.

This katydid nymph climbed up onto the sheet illuminated by the UV light. I am reluctant to say which conehead species she might be.

This katydid nymph climbed up onto the sheet illuminated by the UV light. I am reluctant to say which conehead species she might be.

The season seems barely begun, but already I am closing the book on two species.

The Vermont Cemetery Prairie Preserve in Will County reportedly is one of the few places in the Chicago region which still harbors prairie cicadas. They were done, however, by the time I got there on June 26.

The Vermont Cemetery Prairie Preserve in Will County reportedly is one of the few places in the Chicago region which still harbors prairie cicadas. They were done, however, by the time I got there on June 26.

I have just 3 sites to check next year as good candidates for persisting prairie cicada populations. Protean shieldbacks also apparently are done. I added only 3 county records for them in their brief 2016 season. This was a wakeup call, and I will need to get on my horse right away when they start next year.

 

Recent Travels: Places

by Carl Strang

I have fallen behind on blog posts. The season is heating up, and I have kept busy doing various surveys in various places. Today’s start on catching up will focus on some scenes and miscellaneous photos taken along the way.

The Marquette Trail at Indiana Dunes National Lakeshore passes beautiful marsh and sand savanna habitats.

The Marquette Trail at Indiana Dunes National Lakeshore passes beautiful marsh and sand savanna habitats.

I found northern wood crickets singing along the trail. They bury themselves in leaf litter like this.

I found northern wood crickets singing along the trail. They bury themselves in leaf litter like this.

Another example of a wood cricket song site. I tried to get a look at one, but they choose deeply stacked litter areas with plenty of hidey holes and escape routes.

Another example of a wood cricket song site. I tried to get a look at one, but they choose deeply stacked litter areas with plenty of hidey holes and escape routes.

Painted turtles wandered the savanna seeking good places to lay their eggs.

Painted turtles wandered the savanna seeking good places to lay their eggs.

Another good sand area is Illinois Beach State Park. Here a trail goes through the zone behind the fore dunes.

Another good sand area is Illinois Beach State Park. Here a trail goes through the zone behind the fore dunes.

Farther back from the edge of Lake Michigan, black oak savanna lines the trail.

Farther back from the edge of Lake Michigan, black oak savanna lines the trail.

Though my main interest was singing insects, there were many four-spotted skimmers to enjoy at IBSP.

Though my main interest was singing insects, there were many four-spotted skimmers to enjoy at IBSP.

I also have spent some time in Kendall County. This plains clubtail was at Hoover Forest Preserve.

I also have spent some time in Kendall County. This plains clubtail was at Hoover Forest Preserve.

This year’s Indiana Academy of Sciences bioblitz was at Goose Pond in southern Indiana. I stopped on the way down for a walk at Turkey Run State Park. Ravines there provide many scenes like this.

This year’s Indiana Academy of Sciences bioblitz was at Goose Pond in southern Indiana. I stopped on the way down for a walk at Turkey Run State Park. Ravines there provide many scenes like this.

I didn’t end up taking any scenery shots at Goose Pond. As I was setting up the UV light, I found this mama spider crossing the road, her back covered with babies. All their eyes glittered like jewels in the headlamp.

I didn’t end up taking any scenery shots at Goose Pond. As I was setting up the UV light, I found this mama spider crossing the road, her back covered with babies. All their eyes glittered like jewels in the headlamp.

No Shadow of a Shadow

by Carl Strang

I didn’t find any periodical cicadas out in Addison or Wood Dale this year. That might seem like a strange statement, given that our local main emergence last happened in 2007, and the next is due in 2024.

A 2007 photo of representatives of DuPage County’s two species of 17-year periodical cicadas: Linnaeus’s on the left, Cassin’s on the right.

A 2007 photo of representatives of DuPage County’s two species of 17-year periodical cicadas: Linnaeus’s on the left, Cassin’s on the right.

I had reason to think I might find a few of these amazing critters here this year (they are peaking in Ohio in 2016, by the way). For several generations, now, starting in 1969, significant numbers of the cicadas have emerged 4 years early in the western suburbs of Chicago. This phenomenon, called a shadow brood, since has been found in a few other locations in eastern North America. It generally is thought to be a one-time deal, but the repetitive nature of this local shadow brood has me thinking there has been reproduction each time. Furthermore, the cicadas in the adjacent cities of Addison and Wood Dale appear entirely to have switched to the shadow timing. Residents reported them to be abundant in 2003. I found hardly any there in 2007.

The next shadow brood emergence therefore should happen in 2020. That assumes that there was indeed reproduction in 2003, or at least that local conditions again will result in some cicadas emerging at age 13 rather than 17. Those numbers are significant, as southern broods of related cicada species always are 13-year cicadas. Something caused a switch in some of our cicadas, in 1969 at least, bumping them onto the 13-year track. If they have been reproducing, then the subsequent shadow broods have resumed the 17-year life span. If you have followed this convoluted story, then you can guess why I thought I might find a few periodical cicadas this year. If the shadow brood indeed is all that exists now in Addison and Wood Dale, and something were to cause a few of them to make the 13-year jump now, 2016 is when they would have emerged. Perhaps a few did, but if so I did not hear any singing, nor did I see any shed nymphal exoskeletons, in this year’s tour of the two cities.

I will repeat my route each year, as I have done starting in 2014. A few cicadas out of the millions emerge a year or two early. I will be very surprised if there are any next year, but the anticipation will build as I look to a possible major emergence in Addison and Wood Dale in 2020.

 

Sulfur-winged Variations

by Carl Strang

Memorial Day weekend brought a reunion with my brother, Gary, in our hometown of Culver, Indiana. Among the many reminiscences and activities were a few visits to places where I hoped to find early season singing grasshopper species. By the time I got home I had accumulated 5 county records for sulfur-winged grasshoppers.

This is the source of the name. I was careful in handling them, and released them all unharmed.

This is the source of the name. I was careful in handling them, and released them all unharmed.

Along the way I found color variations, between the genders and between locations.

Here is a typical female at Memorial Forest, Marshall County.

Here is a typical female at Memorial Forest, Marshall County.

Another female from the same population was yellower.

Another female from the same population was yellower.

On the whole, though, females were much less variable than males.

All the females had broad blue bands on their tibias.

All the females had broad blue bands on their tibias.

Males generally were darker than females and, as is typical in grasshoppers, were smaller.

At some sites, males had striking yellow edges on their forewings.

At some sites, males had striking yellow edges on their forewings.

From above, the pale streak resembles a piece of dead grass stem, and breaks up the general dark mass of the grasshopper’s outline.

From above, the pale streak resembles a piece of dead grass stem, and breaks up the general dark mass of the grasshopper’s outline.

Elsewhere males had little or no pale edging.

Elsewhere males had little or no pale edging.

Tibia color also was not consistent. This seems surprising, as the behavior of grasshoppers when they meet often includes a display of tibias.

Sometimes males showed the typical grasshopper pattern of matching female tibia colors, as in this individual from Newton County, Indiana.

Sometimes males showed the typical grasshopper pattern of matching female tibia colors, as in this individual from Newton County, Indiana.

Often, though, the lower tibias were completely black (Memorial Forest).

Often, though, the lower tibias were completely black (Memorial Forest).

There still is time to find sulfur-winged grasshoppers in more of the 22 counties of the region I am surveying, and I will be interested in seeing how these variations play out.

 

Singing Insect Season Opens

by Carl Strang

There have been several early season warm periods this year, allowing the greening of food plants and the higher temperatures that support invertebrate growth. I have anticipated that this might be a relatively early year for the first sound displays by green-striped grasshoppers, and that expectation was realized on Monday when I heard the fluttering buzz of a flying male, and got a glimpse of him as he landed.

Male green-striped grasshopper photographed in an earlier year.

Male green-striped grasshopper photographed in an earlier year.

This was the second-earliest date in 11 years of observations, and was 15 days ahead of the median first display date. As you walk though areas with unmowed grassy growth, listen for a soft buzzing sound. This is the controlled rattling of wings by a grasshopper at the end of a display flight. With some luck you may catch the insect’s motion and get a look at one.

Updated Singing Insects Guide

by Carl Strang

In 2015 I completed my 10th year of studying the singing insects of the Chicago region, and have begun to distribute the species guide that is the project’s main product. The Chicago region for this project includes 22 counties from southeastern Wisconsin around to Berrien County, Michigan. Singing insects are defined here as the cicadas, crickets, katydids, and members of two grasshopper subfamilies with sound displays that people can hear (though the songs of some are so high pitched that only young people can hear them unaided). There are around 100 species, though some I haven’t found outside historical records. I update the guide each year, and this year’s version just reached 100 pages.

Title page 2016

The guide is available for free as a highly compressed PDF document that nevertheless occupies over 5MB, thanks to the many photos. There are maps showing current and historical county records, graphical devices indicating seasonal and time-of-day information, and descriptions of the insects and their songs. Information is presented as well on conservation concerns and ongoing range expansions. To receive the current version of the guide and get on the mailing list for future updates, send your request to me at wildlifer@aol.com.

Christmas, North Carolina

by Carl Strang

My brother Gary and his wife Lisa have moved from the Eastern Shore of Maryland down to coastal North Carolina, and I joined them there for the week around Christmas. Most of our time went into unpacking and some yard work, but there were plenty of moments to explore the surroundings.

One corner of their property extends into a swamp complete with bald cypress “knees.”

One corner of their property extends into a swamp complete with bald cypress “knees.”

Some of the trees also have the iconic southern epiphyte, Spanish moss.

The most charming critter award went to the anoles that climbed the walls, shrubs and yard furniture.

It’s easy to project lots of personality into these little lizards.

It’s easy to project lots of personality into these little lizards.

Most were wearing their basic brown.

Most were wearing their basic brown.

A few switched to green, demonstrating why some call them “chameleons.”

A few switched to green, demonstrating why some call them “chameleons.”

There still were several species of singing insects performing in the unseasonably warm temperatures of those days. I recognized Carolina ground crickets, southern ground crickets (song identical to that of the striped ground cricket of the North), pine tree crickets, and abundant jumping bush crickets. I was left with a mystery, two individuals of a fifth species that sang from lawns after dark. Here is a recording:

Most of the time the spacing between trills was more evenly rhythmic than in this recording.

The recording was made well out in the lawn in front of Gary’s house.

The recording was made well out in the lawn in front of Gary’s house.

I was able to locate the presumed cricket’s position within a few square inches, but unsuccessful in seeing him. He must have been well concealed in a soil crack or tunnel. At first I thought, from the sound and the habitat, that he must be a ground cricket, but his song was louder than most ground crickets and I have never encountered a ground cricket that sings only after dark. A quick review of ground cricket recordings, and those of other likely cricket groups, in the Singing Insects of North America website, failed to turn up a match. If anyone recognizes this, I would appreciate the tip, but it was great to leave North Carolina with a mystery in hand.

 

Field Crickets 2015

by Carl Strang

The spring field cricket and the fall field cricket are our most common members of their genus, both found in all the counties of the Chicago region. They are sibling species, identical in appearance and in song, differing only by season.

Fall field cricket

Fall field cricket

The only way to be sure that spring field crickets are done for the year, or that fall field crickets have begun, is to check the rare locations where only one of the two occurs. I have adopted the practice of counting them on my weekly bicycle rides through nearby Fermilab, where both species live in good numbers. Last year’s pattern was clear.

Two clear peaks in numbers with a well-defined valley between: spring field crickets peaked in mid-June 2014, fall field crickets in mid-September, with a separation in late July.

Two clear peaks in numbers with a well-defined valley between: spring field crickets peaked in mid-June 2014, fall field crickets in mid-September, with a separation in late July.

This year things were different in some ways, but the general pattern held.

The fall field cricket pattern in 2015 again was well defined, with an earlier peak at the beginning of September. The dividing point again was in the second half of July.

The fall field cricket pattern in 2015 again was well defined, with an earlier peak at the beginning of September. The dividing point again was in the second half of July.

The spring field cricket counts were more chaotic, and lower than those for 2014. Weather was a factor here, often rainy, often windy. This affected my ability to count them, but I think there were indeed fewer than in 2014, and also more fall field crickets than last year.

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