Return to Cicadas

by Carl Strang

On Monday I returned to the area where I searched for northernmost lyric cicadas, as described two posts ago. I had thought I heard a swamp cicada at Penny Road Pond, and wanted to listen again to confirm it.

Swamp cicada

Swamp cicada

This time two were singing, and there was no doubt I was hearing swamp cicadas’ percussive vibrato. The observation represented a shift well to the north of my previous northernmost location for the species.

The red star indicates the previous location at West Branch Forest Preserve in DuPage County. Penny Road Pond is marked by the yellow star. The two places are around 12 miles apart.

The red star indicates the previous location at West Branch Forest Preserve in DuPage County. Penny Road Pond is marked by the yellow star. The two places are around 12 miles apart.

I don’t know of any place in my 22-county survey region that has abundant swamp cicadas. As the map shows, I haven’t documented them in many counties. In large part that is because they sing only in the morning, and I have done most survey work in the afternoons and evenings when the majority of singing insects are displaying. On the other hand, I went for many long morning bicycle rides in Starke and Marshall Counties, Indiana, and heard only widely scattered individuals. Such a thin spread prevents me from being confident about finding the swamp cicada’s range boundary in the Chicago region.

Back to Monday of this week. I wanted to employ the bicycle as a tool again, this time to see if I could extend the lyric cicada’s northernmost point beyond last week’s record. I started from Trout Park, where I had heard that individual, and dropped down onto a bike trail that took me north along the Fox River. After going 6 miles without hearing a lyric cicada I turned around and headed back. Shortly after making that turn I heard a single lyric cicada, though, giving me a new north point 5 miles beyond the one reported earlier. That was it, however, as I heard no more on the return ride.

Revised lyric cicada map. The new location brings that species’ known range within 2 miles of the McHenry County border.

Revised lyric cicada map. The new location brings that species’ known range within 2 miles of the McHenry County border.

That is as much as I will do this year to determine the possible northward expansion of these two cicadas. I will be interested in pursuing this study in the future, mindful that the thin scatter of both species will lend some uncertainty to the results.

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New North for Lyric Cicadas

by Carl Strang

Last week I took a morning to see if I could extend the northernmost known locations for the lyric cicada. Its song is easy to recognize, but at the north edge of the range they are few, and finding them takes time.

Lyric cicada

Lyric cicada

Last year the northernmost ones in Cook and Kane County were at the Carl R. Hansen Woods and Tekakwitha Woods Forest Preserves, respectively. This year I found them several miles farther north in each county. In Cook County the new north was at the entrance to the Crabtree Nature Center, 6 miles beyond the previous record and now only 5 miles south of the Lake County border.

Chicago region range map for the lyric cicada. Black dots indicate counties where the species occurs. Red stars indicate northernmost locations known through 2014. Yellow stars indicate northernmost locations found in 2015.

Chicago region range map for the lyric cicada. Black dots indicate counties where the species occurs. Red stars indicate northernmost locations known through 2014. Yellow stars indicate northernmost locations found in 2015.

In Kane County, the new location was in Trout Park, at the north edge of Elgin. This represents a northward shift of 11 miles. Did the cicadas jump so far in just one year? That seems unlikely; I simply may not have looked in the right places in the past. I will continue to follow this each year, as I am doing for species such as the jumping bush cricket and broad-winged tree cricket, and in time should be able to get a sense of how rapidly the range expansion is occurring.

Seeking the Lyric Cicada

by Carl Strang

Last Thursday I searched for the northernmost lyric cicadas, having found them superabundant in Kendall County and absent in the portions of McHenry County I surveyed. This is a woodland species that seems especially common in bottomland forests, so I took advantage of our glacial legacy and followed rivers north and south (rivers developed in low zones between the concentric end moraines), but also stopped at other woodlands along the way.

Lyric cicada, Tibicen lyricen

Lyric cicada, Tibicen lyricen

There clearly is a gradient in density from south to north. In Kendall County, and along the Des Plaines River at the south edge of DuPage County, large numbers of lyric cicadas form loud choruses. In central DuPage County, at locations such as Fullersburg Woods and Mayslake, this is a regular part of the insect fauna, but they are down to countable numbers of individuals.

The clearest indication came as I followed the West Branch of the DuPage River, and continued north beyond it.  At Blackwell Forest Preserve, in west central DuPage County, there was a ratio of 11 lyric cicadas to 18 or so Linne’s cicadas (= 0.61; Linne’s has a fairly uniform density through the area). At Elsen’s Hill, a few miles farther north, the ratio was 4:7 (0.57).  Several miles farther north, at West Branch Forest Preserve, the ratio was 3:7 (0.43). The farthest north I found this species was at Shoe Factory Woods, in north Cook County, where the ratio was 2:12 (0.17).

Shoe Factory Woods has some good prairie and savanna restorations going.

Shoe Factory Woods has some good prairie and savanna restorations going.

By that point, though, cicadas had entered their afternoon lull, and I wasn’t hearing many of any species. Shifting west and driving south along the Fox River, I heard the next lyric cicada at the north edge of St. Charles, a point close in latitude to West Branch Forest Preserve. For now I have a sense of what is happening in the northern edge of this species’ range, but I will continue to monitor them for changes, and to continue seeking that northernmost population in the region.

McHenry County Singing Insects

by Carl Strang

On Saturday I traveled north to McHenry County, Illinois, to continue my regional survey of singing insects. That county is blessed with some impressive sites, and I was able to cover only parts of two of them. Moraine Hills State Park has a wide range of representative habitats covering large acreages.

Wetlands in particular dominate the landscape.

Wetlands in particular dominate the landscape.

Much of the park is spanned by a network of bike paths, and my next survey trip there will involve my bike. I also paid a visit to a McHenry County Conservation District property, Glacial Park.

When I think of Glacial Park I think of glorious vistas.

When I think of Glacial Park I think of glorious vistas.

There are savannas, restored prairie, and wetlands of varied quality.

This marsh looks very good, at least around the edges.

This marsh looks very good, at least around the edges.

The bog so far is holding its own against a fringing ring of reed canary grass.

The bog so far is holding its own against a fringing ring of reed canary grass.

The bog is rich in sphagnum moss, but was quiet on Saturday, so I hope to find sphagnum ground crickets singing when I return in a month or so.

The bog is rich in sphagnum moss, but was quiet on Saturday, so I hope to find sphagnum ground crickets singing when I return in a month or so.

The species count for McHenry County totaled 16, the list mainly overlapping that for Kendall County from the previous day. The differences were interesting, though. Where the day at Kendall was dominated by omnipresent choruses of lyric cicadas, I did not hear a single member of that species in McHenry. At some point I will follow a couple rivers north and south to find the current range limit for that species, which is common in DuPage County not far south of McHenry.

The McHenry woodlands had rattler round-wing katydids, which I did not find in Kendall County, but the latter had Nebraska coneheads which I did not find in McHenry County. I need to find a drier, more open woodland in Kendall County, but the Nebraska conehead likely is a species which, like the lyric cicada, has its northern range limit somewhere between those two counties.

Kendall County Singing Insects

by Carl Strang

On Friday I took a vacation day to begin surveying singing insects in Kendall County, Illinois, just southeast of my home county of DuPage. It was a good, productive day, yielding a total species count of 19.  There are some high quality wet to mesic forests and restored prairies in the four sites I visited.

The best quality forest was in Richard Young Forest Preserve. There were few invasive plants in this sugar maple forest, which was cut by a nice stream or two and had a beautiful little kame named “Hepatica Hill.”

The best quality forest was in Richard Young Forest Preserve. There were few invasive plants in this sugar maple forest, which was cut by a nice stream or two and had a beautiful little kame named “Hepatica Hill.”

Harris and Hoover Forest Preserves show promise for future visits, though I did not pick up many species there on this trip. The most extensive area was Silver Springs Fish and Wildlife Area (formerly Silver Springs State Park).

Silver Springs has good bottomland forest along the Fox River, and a wide range of open lands. This meadow had many prairie grasses mixed in.

Silver Springs has good bottomland forest along the Fox River, and a wide range of open lands. This meadow had many prairie grasses mixed in.

This restored prairie was one of my favorite locations, yielding several singing insect species.

This restored prairie was one of my favorite locations, yielding several singing insect species.

I did not find much in the way of marshland, and no dry oak woodlands or savannas. I will need to see if Kendall County has good examples of such habitats. As for singing insects, highlights included good numbers of broad-winged bush katydids and a couple dog day cicadas, two of the species I am following for southern range boundaries. The dominant singer was the lyric cicada, with loud choruses providing a continuous background through the day.

This gladiator meadow katydid gave me a photo opportunity. Though the reflections from the flash reduce the quality of this as an image, they do a nice job of highlighting the relatively straight rear boundary of the pronotum, helpful in distinguishing this species from the common meadow katydid.

This gladiator meadow katydid gave me a photo opportunity. Though the reflections from the flash reduce the quality of this as an image, they do a nice job of highlighting the relatively straight rear boundary of the pronotum, helpful in distinguishing this species from the common meadow katydid.

The one species that I heard for the first time this year was the Nebraska conehead.

Many Nebraska coneheads were singing along River Road in the north part of Silver Springs and in residential properties adjacent to it. This one agreeably posed.

Many Nebraska coneheads were singing along River Road in the north part of Silver Springs and in residential properties adjacent to it. This one agreeably posed.

I hope to get back to Kendall County at least one more time this year.

Learning to Identify Insect Songs

by Carl Strang

One of the obstacles to a singing insect monitoring program is the large number of various songs that need to be learned for identification. This is not really much different from learning bird songs for breeding bird monitoring, however (except that the total number of species is smaller here). Instead of being daunted by the entire process, it is possible to take the learning process in stages, beginning with the songs that are common and easy to recognize, the ones you have been hearing all along but simply didn’t have the species labels. Here is a list of a dozen suggested species to start with in the first stage: spring field cricket/fall field cricket (their songs are identical), Allard’s and striped ground crickets, snowy tree cricket, common true katydid, black-legged meadow katydid, greater angle-wing, round-tipped conehead, dog day cicada, scissor-grinder cicada, and Linne’s cicada (for more information on these species, try the tags at the head of this post).

Snowy tree cricket, one of the species on the starter list

This list and those that will follow are for northeastern Illinois and northwestern Indiana. There would be substitutions in other parts of the country (I encourage readers elsewhere to make comments here with their own suggestions). Go to reference recordings of these species’ songs, either on-line at the Singing Insects of North America website or through the CD that accompanies the Songs of Insects book. It is not too late this year to hear many of the species on this list on the warmer days, though some are finished or nearly so.

My recommended species list to focus on in the second stage of learning consists of 8 species and groups of species: greenstriped grasshopper, gladiator meadow katydid, Roesel’s katydid ( three species that sing relatively early in the season), and then later, Carolina ground cricket, Say’s trig, sword-bearing conehead, two-spotted/narrow-winged tree crickets (no need to worry yet about separating the two), and the meadow tree cricket group (3-4 species whose songs are essentially identical to the ear and will remain so).

Roesel’s katydid is a species from the second-stage list.

This list of common species either will take you to additional, though still readily available, habitats, or else require a little more of a practiced ear (which practice you got with the first species group). In particular, seek out and spend some time getting familiar with the songs of the Carolina ground cricket and Say’s trig. They need a little more effort to recognize in the field, but once you have them, they will be touchstones for many other species (much as robin songs are for learning bird vocalizations). If you are starting now, you might push the Carolina ground cricket to the first list, as it is one of the few species singing on the cooler days and evenings.

Once you have mastered the second list of species, you are ready for the more subtle distinctions needed to distinguish the songs in the third species list. This includes separating out the song of Linne’s cicada from similar songs by the lyric cicada, and in some areas, swamp and/or northern dusk-singing cicada.

Linne’s cicada

Also, by this point you are ready to distinguish the two-spotted tree cricket song from that of the narrow-winged tree cricket. Also, the broad-winged tree cricket should stand out now from other long-trilling species. In addition, you no doubt have noticed and begun to puzzle out other species that are more idiosyncratic in their distribution or smaller in numbers that you have encountered in your favorite places.

And that brings you to the fourth stage, learning the songs of whatever remaining species may live in the area you wish to monitor. For this you will need a regional guide. In the Chicago region, you can meet this need with the guide I am developing. It is available for free as a .pdf e-mail attachment. Simply request it at my work e-mail address: cstrang@dupageforest.com

As you are learning and listening, pay attention to which songs you can hear clearly, and at what distances, and which are marginal. This will inform the limitations you will need to address or acknowledge in your monitoring.

Mayslake Insect Update

by Carl Strang

The past couple of months have provided new insects to add to the site list at Mayslake Forest Preserve. The great golden digger, a solitary wasp species in which the females dig tunnels in the soil where they provision their young with paralyzed grasshoppers, katydids and crickets, appeared at Mayslake’s flowers in small numbers beginning mid-summer.

Striking in its yellow, red and black colors, this wasp is not aggressive toward people.

Another addition was this tiger moth caterpillar humping its way across the parking lot one mid-day.

As in a cartoon sheepdog, it’s hard to tell which end is which in a static photo.

This is the yellow woolly bear or Virginian tiger moth. Probably pretty common, it nevertheless will be an addition to the Forest Preserve District’s county species list.

I was pleased to get the opportunity to photograph a live lyric cicada.

Usually these are too high in the trees to see easily.

The black collar and large chestnut patches on the pronotum (top of the thorax) are distinctive.

Lately there have been a lot of eastern tailed-blues.

These tiny butterflies don’t seem to land very often, and then seldom show the dorsal sides of their wings.

Autumn advances, and soon these colorful insects will be out of sight, wintering as eggs or other dormant forms.

Early Singing Insects

by Carl Strang

To this point in the season I have heard singing males of 10 insect species in northeast Illinois. All but one began earlier than in any of the years from 2006 to 2011. This is consistent with more general insect phenology this year, and is attributable to a mild winter and a warm March which heated the soil earlier than usual. The only species with a later starting date was the spring field cricket, a species I usually hear first while running or bike riding, activities my back trouble prevented during the critical time period. And yet, despite that limited mobility, I have recorded dates for the other 9 species that ranged 5-22 days earlier than in any previous year (4 of the previous records were in 2007, 5 in 2010, 1 last year; they add up to 10 because of a tie). The only other case perhaps worth singling out was the broad-winged bush katydid, 22 days earlier than last year’s previous record. This species is not abundant or widely distributed, and I suspect it has a longer, earlier season than I have realized before. I should make some effort in future years to get a better handle on its starting and ending dates.

Broad-winged bush katydid

For those who may be interested, here are all the first song dates this year so far. Greenstriped grasshopper 3 April, 17 days earlier than the previous record. Spring field cricket 25 May, 20 days later. Roesel’s katydid 29 May, 11 days earlier. Protean shieldback 5 June, 7 days earlier. Linne’s cicada 14 June, 12 days earlier. Gladiator meadow katydid 14 June, 7 days earlier. Dog day cicada 15 June, 5 days earlier. Scissor-grinder cicada 19 June, 13 days earlier. Broad-winged bush katydid 23 June, 22 days earlier. Lyric cicada 24 June, 6 days earlier.

Singing Insect Season Heats Up

by Carl Strang

We have entered the part of the season when first appearances of mature singing insects accelerate. The transition in DuPage County began with the first gladiator meadow katydid singing on June 30. This was relatively early, though 9 days later than the earliest I have heard them in the 6 years of my study.

Gladiator meadow katydid.

I have to append my description of this species’ song. In the past I have said that they seldom include ticks in their song. I have been listening closely this spring, and in fact there usually are very faint ticks between the much louder buzzes. The ticks are variable. Commonly they seem to trail off from the end of a buzz rather than to lead into the next one as is typical of meadow katydids, but sometimes the latter pattern appears. Most of them have an irregular stuttering pattern in the ticks, though occasionally they are regular. The main distinction remains, however, that the ticks are very faint compared to the volume of the buzzes.

The “annual” cicadas of genus Tibicen were led in by a Linne’s cicada on July 3. The next day brought the first canicularis (dog day) cicada song, in my own yard. A lyric cicada debuted on the 11th, and finally a scissor-grinder (pruinosa) offered the first song on July 15. All of these were middle-of-the-road start dates.

Ground crickets also are due this time of year. The first was, as usual, a striped ground cricket, on July 13.

The most recent start-up was by broad-winged bush katydids, several of which were singing their short, lisping day songs at Fermilab on July 15, an early start for the species.

It’s appropriate here to remind you that I can e-mail my free guide to singing insects of the Chicago area to those who request it at my work address: cstrang@dupageforest.com

Comparative Block Counts

by Carl Strang

In 2010 I made enough counts of singing insects in the small rural town of Culver, Indiana, to compare them to my block counts in Warrenville, Illinois, of the Chicago suburbs.

I walked around similar sized blocks in the two locations, counting the singing insects I heard. This is the south side of the Culver block.

The species count in Culver was 14; differences in species from Warrenville were the absence of Say’s trigs and common true katydids, and the addition of the lyric cicada.

Three species at Culver were abundant enough and showed enough of a difference in median counts to make statistical comparisons worth trying. Culver had more fall field crickets (median count 6, vs. 0 for Warrenville), fewer striped ground crickets (median counts 9.5 and 17 in the period of time covered by the Culver counts), and no statistically significant difference in greater anglewings (median counts 0.5 and 3.5 in Culver and Warrenville, respectively, during the sampling period,).

The Warrenville neighborhood had few fall field crickets in 2010. They were much more abundant in Culver.

I also heard two unfamiliar songs at Culver that may represent additional species. The first of these sang soon after dark on July 31, from a point off the ground and of the speed and pattern of an Allard’s ground cricket, but composed of dry clicks or ticks rather than notes or tones (listening to reference recordings the next day, I thought the most likely possibility was handsome trig).

During a Culver block count on September 4 I heard another unfamiliar song. The temperature was cool, between 55 and 60F, so the song may have been slowed. It had two parts, each consisting of fairly rapid phrases. The first part’s phrases were like doubled ticks, lispy in quality, produced for several seconds. The second part consisted of single ticks, reminiscent of the greater anglewing, lasting much longer (several seconds), and at a distinctly more rapid rate than in the first part. This pattern seems best to fit some member of the subfamily Phaneropterinae, the false katydids.

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