Jumping North

by Carl Strang

Of the many species of singing insects that have expanded their ranges northward in the past half century, the jumping bush cricket (Orocharis saltator) has been the fastest mover in the Chicago region. I have done my best to keep up with them ever since 2007, when I first heard their bell-like chirps in DuPage County, Illinois. As their density built dramatically in southern DuPage, the front of their advance typically shifted half a mile north each year.

Jumping bush cricket

At the same time, they were on the move to the east in Cook County. I first found them in Kane County, to the west, in 2014. The line of their advancing front has angled southwest to northeast, suggesting an Indiana source of the invasion, though last year I heard them singing just north of Peoria, well southwest of the Chicago region.

Over the past couple of years, what seemed to be a simple spread has become complicated. First, the advance apparently stalled out in the northeast corner of Cook County, just south of the Lake County border. Farther west, however, the crickets’ expansion has, if anything, accelerated. Following the Fox River, they have moved 8 miles up its east bank in 3 years.

But that’s not all. This year I found them even farther north on the west bank. Then, on September 20, I heard jumping bush crickets singing at the edge of Wauconda, in western Lake County. Subsequent checking revealed that this is an isolated small group, probably a human-assisted introduction. I will be interested in seeing if they successfully reproduce there. In any case, there is no end in sight to the dramatic northward movement of this species, and I will continue to invest some time each year in documenting it.

Map of the Chicago region, showing locations for jumping bush crickets. Black dots indicate counties where the species has become established. Stars indicate farthest north locations: red for 2014, yellow for 2015, green for 2016, and the two blue stars indicate new north locations in 2017, along the west bank of the Fox River in Kane County, and at Wauconda in Lake County.

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Ecoblitz Continued

by Carl Strang

The Indiana Forest Alliance, a non-profit conservation organization, has been sponsoring a species survey in portions of two state forests in southern Indiana. As it consists of repeated weekend sessions over a period of years, they are calling it an “ecoblitz” rather than a bioblitz, which is a one-time event limited to a 24- or 48-hour time span. I went down for a weekend last fall, and returned in early August to complete the singing insects portion of the survey.

The area is forested, except for some small areas of tall, dense herbaceous growth in stream bottoms. The singing insect fauna consequently is mainly of forest species.

Confused ground crickets were common on the forest floor.

Confused ground crickets were common on the forest floor.

Say’s trigs by the hundreds sang in the open herbaceous areas.

Say’s trigs by the hundreds sang in the open herbaceous areas.

Widely scattered small groups of rattler round-winged katydids could be heard at night.

Widely scattered small groups of rattler round-winged katydids could be heard at night.

This nymph is recognizable as a male fork-tailed bush katydid by the distinctive appendages at the tip of his abdomen.

This nymph is recognizable as a male fork-tailed bush katydid by the distinctive appendages at the tip of his abdomen.

Some of the other species that sang for us were swamp cicadas, Nebraska coneheads, lesser angle-wing katydids, jumping bush crickets and common true katydids.

I also helped with photography at a night-time moth survey at illuminated sheets.

This small-eyed sphinx was one of the two hummingbird moths we attracted.

This small-eyed sphinx was one of the two hummingbird moths we attracted.

A blinded sphinx also dropped in.

A blinded sphinx also dropped in.

A grape leaffolder

A grape leaffolder

This lesser grapevine looper appears to be sending out pheromone.

This lesser grapevine looper appears to be sending out pheromone.

A Cope’s gray treefrog hopped in, possibly sensing the smorgasbord we had created.

A Cope’s gray treefrog hopped in, possibly sensing the smorgasbord we had created.

 

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.

 

Jumping Bush Crickets 2015

by Carl Strang

Of the many species of singing insects that have shifted their range boundaries significantly northward in the last half-century, the one that is continuing to move most rapidly is the jumping bush cricket.

Jumping bush cricket

Jumping bush cricket

In recent years I have been tracing the northernmost locations where I am hearing the distinctive songs of this cricket in northeast Illinois.

Chicago region map of jumping bush cricket locations. Black dots mark counties where I have found the species to date. Red stars indicate specific locations where I found northernmost crickets singing in 2014. Yellow stars mark places farther north where I heard them in 2015.

Chicago region map of jumping bush cricket locations. Black dots mark counties where I have found the species to date. Red stars indicate specific locations where I found northernmost crickets singing in 2014. Yellow stars mark places farther north where I heard them in 2015.

The line marking the front of this expansion is diagonal, southwest to northeast, an orientation that seems to point back toward Indiana as the source of this spread. In the central part of the line I found no indication of an advance from 2014 to 2015, but elsewhere there was a shift of about half a mile. If at some point the movement stalls out, I would expect the west end of the line to catch up with the east end and even up latitudinally, unless there is a Lake Michigan climatic influence.

Morgan Monroe-Yellowwood Ecoblitz

by Carl Strang

The Indiana Forest Alliance is sponsoring a multi-year species survey of the back country portion of the conjoined Morgan Monroe and Yellowwood State Forests in Monroe and Brown Counties of southern Indiana. They are holding bioblitz weekends at various seasons so as to get a more complete picture than a single bioblitz would produce. Jeff and Mary Stant are providing the principal organizational and logistical support. I paid my first visit on September 12 to begin inventorying the singing insect species.

While waiting my turn to go into the survey area, I checked out the base camp in an old field with scattered young trees adjacent to the riparian edge of a wooded stream. The species mix was much like I would expect to find in a dry area in northern Indiana or Illinois.

Woodland meadow katydids were very common in woodland edges, much more abundant than I have found them farther north.

Woodland meadow katydids were very common in woodland edges, much more abundant than I have found them farther north.

The old field held scattered common meadow katydids.

The old field held scattered common meadow katydids.

Handsome trigs also were common in the riparian edge.

Handsome trigs also were common in the riparian edge.

Allard’s ground crickets were one of several species at the camp.

Allard’s ground crickets were one of several species at the camp.

The forested survey area was, as expected, less diverse, though the cool afternoon temperature probably inhibited some species. The slopes held scattered confused ground crickets, and bottomland herbaceous thickets were full of Say’s trigs, along with good numbers of Carolina ground crickets and more scattered jumping bush crickets and narrow-winged tree crickets.

At one point we flushed out a medium-sized cricket which permitted a quick photo but evaded capture. It was one of the camel crickets, probably in genus Ceuthophilus.

At one point we flushed out a medium-sized cricket which permitted a quick photo but evaded capture. It was one of the camel crickets, probably in genus Ceuthophilus.

We went up to a ridge top in the evening. It was very cold, and few species were managing to sing. There were scattered tinkling ground crickets, Carolina ground crickets, jumping bush crickets, and a few feebly ticking long-spurred meadow katydids. A background hum came from the forest canopy, and occasional individuals could be distinguished to support an identification of Davis’s tree crickets, by far the most abundant singers on that cold night.

I look forward to returning for more ecoblitz weekends next year.

 

Jumping Bush Cricket Advances

by Carl Strang

The jumping bush cricket is the singing insect species that is shifting its range boundary most rapidly to the north in the Chicago region.

Jumping bush cricket

Jumping bush cricket

This one is worth following annually, and a couple weeks ago I made a few evening drives to find how far they have advanced this year.

Here is the resulting map, on the scale of the 22-county area I am surveying for singing insects. Black dots represent counties in which I have found the species as of last year. Red stars mark the northern extent in 2013, yellow ones 2014.

Here is the resulting map, on the scale of the 22-county area I am surveying for singing insects. Black dots represent counties in which I have found the species as of last year. Red stars mark the northern extent in 2013, yellow ones 2014.

The four yellow stars are in four stream corridors that the crickets sometimes follow. I did not do this check along the West Branch of the DuPage River last year. As you can see, there was a measurable hop north. For the first time I found them in Kane County; they were just south of there in Kendall last year. Also, now they have extended into northern Cook County both along Salt Creek and the Des Plaines River. These new locations represent about a half-mile northward shift, and I will be interested in finding whether they maintain that rate next year.

 

Another River Heard From

by Carl Strang

In a recent post I shared the northward progress of jumping bush crickets in DuPage County. I thought I was done with them for the season, but their numbers seemed to increase over the past couple of weeks, and I was toying with making another check. The opportunity came on Friday. After work I drove up into Lake County to pick up my race packet for a half-marathon I was running on Saturday. On the way back I drove down along the Des Plaines River in Lake and Cook Counties, windows open on a reasonably warm evening. The result was a new north location for the species, just south of the split between Milwaukee Avenue and River Road in Cook County.

Regional species map for the jumping bush cricket. Black dots indicate counties where they have been found to occur so far. The red stars indicate the farthest north locations for Kendall, DuPage and Cook Counties, the last decidedly north of the others.

Regional species map for the jumping bush cricket. Black dots indicate counties where they have been found to occur so far. The red stars indicate the farthest north locations for Kendall, DuPage and Cook Counties, the last decidedly north of the others.

The pattern seems clear. Of the four major north-south rivers that provide the best travel corridors for jumping bush crickets, they have gone farthest north along the Des Plaines River, the easternmost. Next comes Salt Creek, which flows into the Des Plaines at the Brookfield Zoo. Most of DuPage County is drained by the two branches of the DuPage River, whose crickets are yet a little farther south. My earlier check of the Fox River, just west of DuPage, turned up no jumping bush crickets, but I started my search at North Aurora. Might they be a little farther south than that? Last night I checked that possibility, and found them abundant at Kendall County’s Richard Young Forest Preserve. Upstream (north) from there I found a lot of good looking but empty habitat, and then a pocket of the crickets just north of the town of Oswego, still in Kendall County (the lowest star on the map). They are within 2 miles of the Kane County border, but apparently haven’t reached that county yet. So, the northward advance of jumping bush crickets is marked by a line extending southwest from the northernmost red star in the map. It seems likely that they have spread up into northeast Illinois from Indiana, by way of the Kankakee River and perhaps by a broader flow through towns and preserves closer to Lake Michigan.

Jumping Bush Crickets Continue North

by Carl Strang

Of the several species of singing insects that have been expanding their range northward, the jumping bush cricket is the one whose northern boundary has not yet extended beyond DuPage County. Each year I have sought out their north point, and each year it has moved. This year is no exception, and in fact their repetitive burry chirps soon will be heard in north Cook County if the trend continues.

Jumping bush cricket. They are about the same size as a field cricket, but live in trees rather than on the ground.

Jumping bush cricket. They are about the same size as a field cricket, but live in trees rather than on the ground.

Here is the updated map. Green circles indicate known jumping bush cricket locations. This year’s extension is represented by the two northernmost circles in the northeast corner of the county.

Here is the updated map. Green circles indicate known jumping bush cricket locations. This year’s extension is represented by the two northernmost circles in the northeast corner of the county.

The crickets seem to use our north-south streams as travel corridors, and so I took an evening to scout for them along the Fox River, in Kane County just east of DuPage. I heard none on either side of the river from my starting point in North Aurora to the turn in Geneva, though the habitat looks very good. My hypothesis from this is that they spread from Indiana via the Kankakee River to the Des Plaines/Illinois River, and reached DuPage County via Salt Creek and the branches of the DuPage River. The Fox meets the Illinois well to the west, and so additional years will be needed for the crickets to reach central Kane County, either via the Fox or by spreading westward from the West Branch of the DuPage River.

Incidentally, I have tested an idea I had last year, and so far it seems to be working. The jumping bush cricket’s song is loud enough to be heard easily from the car on a driving survey. Seeing one is difficult, however. I have found that they are singing from perches on tree trunks, especially from small shelters in the bark, and the reflecting foliage layers around them confound the source. Looking up the trunk for the lifted, vibrating wings, often leads to success. Another student of singing insects, Lisa Rainsong, has reported in her excellent blog that in her yard in the Cleveland area, they are difficult to find for another reason: they are very active, shifting locations between songs.

Singing Insects Range Extensions

by Carl Strang

My other presentation at Saturday’s Wild Things conference reviewed the range extensions by 8 species of singing insects that have turned up in our region in recent years. I ran through them in the chronological order of their discovery, and then offered some general points.

Broad-winged tree cricket (Oecanthus latipennis)

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Map from the Singing Insects of North America website (SINA), 2012. The record in DuPage County resulted from this study, and was added in 2006. Prior to that the species was not supposed to occur in the Chicago region.

Map from the Singing Insects of North America website (SINA), 2012. The record in DuPage County resulted from this study, and was added in 2006. Prior to that the species was not supposed to occur in the Chicago region.

Original range sources: Hebard 1934  (“Northern limits of distribution are Hilliary and Quincy”), McCafferty & Stein 1976 described it as a central and southern species in Indiana, with Tippecanoe County the northern extent. I found them in DuPage County in 2006, and subsequently learned they are abundant throughout the county. They also have reached the junction of the Wisconsin and Mississippi Rivers in Wisconsin.

Jumping bush cricket (Orocharis saltator)

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Jumping bush cricket SINA map, 2012. The added red line indicates the northern range limit as of 1969, when Tom Walker reviewed the genus.

Jumping bush cricket SINA map, 2012. The added red line indicates the northern range limit as of 1969, when Tom Walker reviewed the genus.

Original range sources: Hebard 1934 (Shawneetown northern limit in Illinois; “should however be found throughout southern Illinois as it is known as far north as central Indiana”). McCafferty & Stein 1976 (“known only from the southern two-thirds of the state” with Tippecanoe County given as the northern limit). They are rapidly expanding in DuPage County, abundant in the southern half and spreading into the northern half with new northern limits found annually. I also have heard them at Indiana Dunes State Park.

Roesel’s katydid (Metrioptera roesellii)

Roesel's s-wing female Purdue b

Roesel’s katydid SINA map, 2012. Prior to work by Scott Namestnik and me, the range was thought to end in northeastern Ohio, with a small disjunct area in northeast Illinois. The red dots indicate our added findings in 2012.

Roesel’s katydid SINA map, 2012. Prior to work by Scott Namestnik and me, the range was thought to end in northeastern Ohio, with a small disjunct area in northeast Illinois. The red dots indicate our added findings in 2012.

Original range sources: Roesel’s katydid is a European species that in North America first was found in two suburbs of Montreal, Quebec (Urquhart and Beaudry 1953, Beaudry 1955), and is thought to have been introduced between 1945 and 1951. Vickery (1965), who summarized this history, reported that the species had spread into New York state and Vermont by 1965, and that the long-winged variants that originally had dominated the Montreal population were diminishing in favor of the short-winged forms typical of the European continent. The Montreal population apparently was by then limited by an indigenous parasitic nematode. Roesel’s reached Ithaca, NY, by 1965 (G.K. Morris, as reported by Shapiro 1995), and Long Island by 1990 (Shapiro 1995). Short-winged forms were dominating the St. John, New Brunswick, population by 2008 (McAlpine 2009), and so had arrived some unknown number of years earlier. Nickle (1984) reported finding them in Pennsylvania by the early 1980’s. Roesel’s katydids were collected in two northeastern Illinois counties in the late 1990’s (Eades and Otte, no date). I found them in north central Indiana in 2007, and subsequently Scott Namestnik and I have found them throughout northern Indiana (as far south as Indianapolis) northeast Illinois, and last year the Lower Peninsula of Michigan. Others have added Ohio, Wisconsin and eastern Iowa.

Round-tipped conehead (N. retusus)

Roesel’s katydid SINA map, 2012. Prior to work by Scott Namestnik and me, the range was thought to end in northeastern Ohio, with a small disjunct area in northeast Illinois. The red dots indicate our added findings in 2012.

 

Round-tipped conehead SINA map, 2012. The added red line indicates the northern extent of the range in Illinois in 1934 and in Indiana in 1976.

Round-tipped conehead SINA map, 2012. The added red line indicates the northern extent of the range in Illinois in 1934 and in Indiana in 1976.

Original range sources: Hebard 1934 (“Urbana is a northern limital point”), and McCafferty and Stein (1976) had none north of Indianapolis, but they are so common in northwest Indiana and northeast Illinois now that this is a well advanced range expansion in the intervening decades. I also heard a single singing individual in a meadow at Wyalusing State Park in Wisconsin in 2007.

Handsome trig (Phyllopalpus pulchellus)

Handsome trig 2b

Handsome trig SINA map, 2012. The northern dot at St. Joseph County, Indiana, is the result of Scott Namestnik’s work.

Handsome trig SINA map, 2012. The northern dot at St. Joseph County, Indiana, is the result of Scott Namestnik’s work.

Original range sources: Hebard 1934 (northern limits given as Marion County in Indiana and Monticello in Illinois; “confined to southern and central Illinois”). McCafferty & Stein 1976 indicated a northern extent in Tippecanoe County. In 2009 Scott Namestnik was posting photos of them from St. Joseph County.

Swamp cicada (Tibicen tibicen)

Swamp cicada 4AU 4b

Original range sources: This species was mentioned by Alexander, Pace and Otte in their (1972) Michigan singing insects paper, but they expressed doubt that it was a breeding species in the state. However, a later paper (Marshall, Cooley, Alexander and Moore 1996) reported finding it in extreme southern MI (intensive searching found it only in the southern portions only of the southern tier of counties. They were not willing to say whether this represented a range extension or the species being missed earlier). I first found it in Marshall County, Indiana, and DuPage County, Illinois, in 2010, but suspected I had heard it earlier. They are scattered across the southern half of DuPage.

Slightly musical conehead (N. exiliscanorus)

Slightly musical Max Wet b

Slightly musical conehead SINA map. This does not yet reflect our finding them in Porter and Marshall Counties, Indiana, in 2012.

Slightly musical conehead SINA map. This does not yet reflect our finding them in Porter and Marshall Counties, Indiana, in 2012.

Original range sources: Hebard 1934 (northern limits indicated as Tower Hill in south central Illinois, and New Harmony in Indiana). McCafferty & Stein 1976 (“In Indiana it is known only from heavy thickets and grasses along the Ohio River”). Gideon Ney, Nathan Harness and I, seeking slender coneheads, found this species at the Indiana Dunes National Lakeshore in 2012, and I found it in Marshall County as well.

Marsh conehead (N. palustris)

Slightly musical conehead SINA map. This does not yet reflect our finding them in Porter and Marshall Counties, Indiana, in 2012.

 

Marsh conehead SINA map. This does not yet reflect our finding them in Porter County, Indiana, in 2012.

Marsh conehead SINA map. This does not yet reflect our finding them in Porter County, Indiana, in 2012.

Original range sources: Hebard 1934 (“Lawrenceville and Carbondale are northern and western limits respectively for palustris…It is probably confined to the southern portions of Indiana and Illinois.”). McCafferty & Stein 1976 reported Tippecanoe County as the northern known extent. Ney, Harness and I found this species to be common at Indiana Dunes National Lakeshore and present in the state park.

General Points

Most of these range extensions are from south to north. Exceptions are Roesel’s katydid (east to west) and the broad-winged tree cricket (spreading south as well, according to SINA coordinator Tom Walker).

I do not know whether any other of these species likewise are spreading south or in other directions.

Some of these are clear range expansions, as they are species which were well known at the time of earlier studies, and now have become abundant beyond the range as then drawn: broad-winged tree cricket, jumping bush cricket, Roesel’s katydid, and round-tipped conehead.

The others have a spottier distribution, or may not have been as well known then, and so might have been missed by earlier researchers: handsome trig, swamp cicada, slightly musical conehead, and marsh conehead.

As for the possible connection between these range extensions and climate change, Gonzalez (2012) mentioned a calculation, based on work in Gonzalez et al. (2010), indicating that the region’s climate has undergone a temperature change equivalent to a southward shift in latitude of 100km in the 20th century. This is consistent with the magnitude of many of these observed range changes.

Jumping Bush Cricket Range Expansion

by Carl Strang

In 1969, when Thomas Walker reviewed North American bush crickets, his paper (accessible through this link) showed the range of the jumping bush cricket, which then included the southern halves of Indiana and Ohio, and the southern third of Illinois. Since then they have expanded north, as I mentioned in my post earlier in the week which included photos of the species. The front of their northern extent now is in DuPage County. Here is where I have found them to date:

Green circles indicate locations, which in some cases represent one or two individuals, in others dozens.

The map is more representative of western DuPage than of the eastern half of the county, but I’m confident of the northernmost positions. The easternmost spread is taking place mainly along Salt Creek, and I imagine a similar expansion is happening along the Des Plaines River to the east. I know they have reached at least Batavia along the Fox River to the west. The northernmost circle in western DuPage was an isolated couple of individuals, and they were close to a plant nursery, so they might have been transported there. If so, it seems only a matter of a few years before the general front will extend that far.

Jumping bush crickets now are abundant in southern DuPage, the northern edge of their densest numbers this year roughly coinciding with route 56 (Butterfield Road).

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