Closing the Book on Prairie Cicadas

by Carl Strang

The prairie cicada is a small (1-inch) insect that occurs in a few remnant prairies in northeast Illinois. Work by Dennis Nyberg and associates at the University of Illinois Chicago has revealed much of what is known about them in the state. I first gained experience with this species a few years ago at the UIC’s Woodworth Prairie in northern Cook County, then quickly discovered them in two DuPage County locations. I expected then that I would find them consistently in prairie remnants, but this has not proven to be the case.

Prairie cicada, June 2017

Recently I finished checking the last of the remnant prairies I know about in the Chicago region, and have not added any more locations to the UIC group’s 8 sites (they also listed 3 sites in downstate counties). I have not found them anywhere in the region’s Indiana or Wisconsin counties.

All the sites are small, so all the populations are small and vulnerable. Mated females do not disperse beyond their little prairie plots, as far as anyone has been able to determine. If the species is to survive in the region, the landholders (mainly forest preserve districts and railroads) will need to continue managing those sites so that the prairies can persist, and prairie cicadas with them.

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.

 

Bush Cicadas

by Carl Strang

Illinois has lost nearly all the remnants of its original prairie. Thanks to the efforts of conservation agencies and private organizations you can find prairies to enjoy, but these are restoration projects for the most part. Restored prairies are nice gardens, but they lack a significant portion of the animal life. It’s a mistake to assume that “if you build it they will come.” Too many obligate prairie insects and other animals are not good dispersers. The highest priority has to be preserving the remnants, when there is a choice between devoting resources to that or to developing restorations.

A case in point is the prairie cicada, which I have featured here in the past. Another is the bush cicada. I made a trip south of the Chicago region last week to get some experience with that species, so I would know what to listen and look for in my 22-county survey area. A 2-hour drive took me to the southern fringe of Iroquois County, to the Loda Prairie State Nature Preserve.

This remnant is only 12 acres, but its quality is excellent.

This remnant is only 12 acres, but its quality is excellent.

The term “charismatic fauna” is over-used. The bush cicada is the first Illinois insect I have encountered to which I would apply that term.

For one thing, they are big and colorful.

For one thing, they are big and colorful.

They also are noisy like the other species in genus Neotibicen (formerly Tibicen, the change justified in a paper just out this year from the UConn cicada group plus an Australian researcher). I was pleased to find bush cicadas are fully as audible as our familiar Neotibicen species.

Linne’s cicada, for instance.

Linne’s cicada, for instance.

The song is like a slowed lyric cicada song, the pulse rate closer to that of Linne’s but with sharp, separate pulses. The singing was in bouts, with sometimes 10 minutes of silence between, so that the males seemed to cue their singing off of one another. They also were very active, many of the males flying to a new perch after every song. Though their flight generally was well controlled, once one bounced off the side of my head.

A male bush cicada in full song.

A male bush cicada in full song.

In the following days I sought them in several Chicago region counties, without success. The silence of those prairie remnants, some suffering from invasion by gray dogwood and other problem plants, was a sad contrast to Loda Prairie. In fairness, though, the bush cicada is primarily a southern and western species that may never have reached into the Chicago region. That won’t keep me from continuing to seek it here, though.

Prairie Cicadas Ran Late

by Carl Strang

Prairie cicadas are very locally distributed in northeastern Illinois, and I have not yet found them in Indiana or Wisconsin. Their season is brief and variable, and so I rely on a population near my home, at West Chicago Prairie Forest Preserve, to tell me when they are active each year. This year has been a bust in my search for new populations. The largest number I counted at West Chicago Prairie was only 4, on July 12, and they were difficult to pick out among the many gladiator meadow katydids, whose briefer buzz has a similar sound quality. Usually the cicadas are finished before the gladiators become numerous. There were no cicadas singing in my final check yesterday.

Side view of one of this year’s few singers.

Side view of one of this year’s few singers.

Dorsal view of the same individual. These guys are little, about an inch long.

Dorsal view of the same individual. These guys are little, about an inch long.

At least some cicada species have the ability to postpone emergence by a year. Perhaps the rain or periods of cool weather at the beginning of the usual emergence period persuaded some of these to wait. If so, there may be increased numbers next year, and I will be able to resume my search for undiscovered populations.

Not an Indicator?

by Carl Strang

Prairie cicadas are small, early-season cicadas that I first met on July 4 of last year at Woodworth Prairie in Cook County. Soon after that I found them at West Chicago Prairie and Belmont Prairie in DuPage County. Researchers at Woodworth have documenting them as emerging during a relatively brief period, mid-June to mid-July. This year I have been making weekly checks at West Chicago Prairie, and they did not appear until last Sunday, July 6.

This one sang from a bush clover stalk.

This one sang from a bush clover stalk.

That opened the door to seeking them on other sites, and I have been to two of them so far. I failed to find prairie cicadas at Horlock Hill Prairie in Kane County and at Wolf Road Prairie in Cook County. That spoils my working hypothesis that they would prove to be indicators of prairie remnants.

Here’s another West Chicago Prairie cicada, singing from a dead stem.

Here’s another West Chicago Prairie cicada, singing from a dead stem.

I hope to squeeze in a few more site checks in the next couple of weeks, but already I have the sense that this species is very limited in the locations where it occurs. I’ll also hope to get a sense of how long they are out at a given site. The July 6 appearance seems late, but this has been an odd year phenologically. So far the 11 species of singing insects have ranged from the earliest starting date in my record to nearly the latest, and the median is right in the middle. That is a little surprising given the severity and length of the winter, but first flower dates (which I hope to analyze soon) have been equally all over the place.

Sound Ideas: Prairie Cicada

by Carl Strang

Back in early July I first encountered a species I then called the short-grass prairie cicada (Okanagana balli). Its more commonly used English name has proven to be simply “prairie cicada.”

Prairie cicada. These are little guys, about an inch long.

Prairie cicada. These are little guys, about an inch long.

Here is one of the recordings of its song that I made at Woodworth Prairie:

The song doesn’t change, so you may decide not to hear all of the recording, though if you listen carefully toward the beginning you may hear a more distant individual when the recording’s main subject pauses. The song was loud enough that someone with younger ears, or me with the SongFinder pitch-reducing device, could hear it from more than 100 feet away. Unaided I needed to be within 20 feet or so.

The song is continuous, and simple, but there are so few other insects singing in late June or early July in the prairies that there is no confusion. Females clearly have no problem homing in on the singing males.

Prairie cicadas preparing to mate.

Prairie cicadas preparing to mate.

I have made a list of places in several counties where I will be seeking this species next year. I want to test the hypothesis that this is a species of prairie remnants and not of restored prairies.

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