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.

Season’s End Photo Bag

by Carl Strang

Time to share miscellaneous left-over photos from this year’s singing insects prospecting trips. These are pictures that didn’t fit the posts that covered the locations where they were taken. All are from within my 22-county survey area.

This regal fritillary fed from blazing star flowers at an eastern Illinois location far from this rare species’ main Illinois range.

This regal fritillary fed from blazing star flowers at an eastern Illinois location far from this rare species’ main Illinois range.

Though field guides describe the common checkered-skipper as eastern North America’s most abundant butterfly, it is not one I encounter very often.

Though field guides describe the common checkered-skipper as eastern North America’s most abundant butterfly, it is not one I encounter very often.

This bush katydid flew to a high perch on a tree but remained just long enough for me to take a distant photo before moving on. I don’t know enough to identify the species.

This bush katydid flew to a high perch on a tree but remained just long enough for me to take a distant photo before moving on. I don’t know enough to identify the species.

Handsome trig. I added one more Indiana county to the ones where I have found this cricket, but have yet to find it in any of the Chicago region’s other states.

Handsome trig. I added one more Indiana county to the ones where I have found this cricket, but have yet to find it in any of the Chicago region’s other states.

Straight-lanced meadow katydid. I found this species in 6 more counties in 2015, in Wisconsin, Illinois and Indiana.

Straight-lanced meadow katydid, long winged form. I found this species in 6 more counties in 2015, in Wisconsin, Illinois and Indiana.

Broad-winged Tree Crickets 2015

by Carl Strang

The broad-winged tree cricket was the first singing insect species I found (in 2006, the first year of my study) that had shifted its northern range boundary significantly.

Broad-winged tree cricket

Broad-winged tree cricket

In contrast to the jumping bush cricket, this one seems to be moving slowly, but I have not followed it as closely. This year I put some time into locating northernmost singers, and found two locations.

Chicago region map of broad-winged tree 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 this year.

Chicago region map of broad-winged tree 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 this year.

These will be the starting points for next year’s check. The Kane County location is only 1.5 miles south of the southern McHenry-Lake County border line.

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.

Spotted Ground Cricket

by Carl Strang

Spotted ground crickets have been a challenge for me. There are old records of them in several of the counties I am surveying for singing insects, but I had not found them prior to this year. Prompted by Lisa Rainsong’s results from the Cleveland area, I made a goal of finding them this year. I knew what the problem was: to my ear, recordings of their songs are very similar to those of Carolina ground crickets, which I have found throughout the region. Here is one of my recordings of the latter species, made at 58 degrees Fahrenheit (all recordings in this post have been equalized to remove low-frequency background noise, mainly from traffic):

Here is another, this one at 56 degrees F.

I describe the Carolina ground cricket’s song as a continuous purr or very rapid trill, in which pulsing sections alternate with steadier trills that do not pulse.

Contrast those sounds with the following two recordings of spotted ground crickets. The first was made at around 80 degrees F.

The second was made at 71 degrees F. There is a noticeable drop in both pitch and rapidity of the pulses.

After my experience this year I feel confident that I can distinguish the spotted ground cricket’s song, but I still need to listen carefully. The pulses are regular and continuous, lacking the non-pulsing sections of the Carolina ground cricket’s song. The sound is rougher, grittier, and I would not describe it as a purr. Also, study of sonographs reveals that the spotted ground cricket actually has minute pauses between the pulses, in contrast with the Carolina ground cricket’s more continuous sound production.

Here is a female spotted ground cricket. The mottled, spotted pattern especially of her abdomen is a source of the name.

Here is a female spotted ground cricket. The mottled, spotted pattern especially of her abdomen is a source of the name.

This male spotted ground cricket is missing a hind leg, possibly the result of a battle with another male. The yellowish rims around the compound eyes are a prominent feature of this generally brown species.

This male spotted ground cricket is missing a hind leg, possibly the result of a battle with another male. The yellowish rims around the compound eyes are a prominent feature of this generally brown species.

So far it seems to me that spotted ground crickets prefer closed-canopy forest or woodland areas with some accumulations of leaf litter where forest floor vegetation is sparse. The soil needs to be well drained yet moist. Most commonly this seems to mean soils heavy in sand or gravel, but hillsides with denser soils sometimes have spotted ground crickets, too, and I have found them in several of DuPage County’s clay-soil woodlands.

 

Nimble Meadow Katydid

by Carl Strang

After leaving Sarett Nature Center I drove down to central coastal Berrien County. A GoogleEarth study of the southern Lake Michigan shore had pointed to Grand Mere State Park as a site with wetlands that might contain some of the rarer meadow katydids. As it happened, I missed one of the signs pointing to the park entrance, and found myself on a road bordering a small lake. This proved to be a lucky accident. I stopped at a sandy informal boat launch, and when I waded out a short distance I heard unfamiliar buzzes coming from a patch of pickerel weeds.

A few bulrushes and water knotweeds were mixed with the pickerel weeds.

A few bulrushes and water knotweeds were mixed with the pickerel weeds.

I soon found that the water was too deep for my knee boots, which rang a bell. I quickly changed out for hip boots, grabbed sound recorder and camera, and returned. Here is what I heard:

It reminded me of the song pattern for the woodland meadow katydid, except that the ticks between the buzzes were fewer, and I could hear the song clearly unaided (i.e., without needing the pitch-lowering SongFinder device). By this time I was sure I must be hearing nimble meadow katydids. Very little has been published about them. Morgan Hebard in his 1934 monograph on Illinois Orthoptera said he found them only where the water was waist deep (hm, now that I think about it, he did not give his height). I had searched for them by kayak in a few places, without success. As I waded out I found the pickerel weed patch was in water knee to mid-thigh in depth. I also found that both hip boots were leaking. I began getting glimpses of the katydids, and soon discovered they were well named. They were quick to fly, and flew up to 20 feet. One did something totally unexpected: he dove beneath the water and hid among the submerged stems.

Eventually I was successful in getting some photographs, and in catching a katydid for cerci shots.

Nimble meadow katydid. The head is colored like that of the black-legged meadow katydid, the hind femora green like those of dusky-faced meadow katydids, but with brown tibias, and it is the same size as those species, but the most distinctive feature is the yellow end of the abdomen, reminiscent of the much smaller short-winged meadow katydid.

Nimble meadow katydid. The head is colored like that of the black-legged meadow katydid, the hind femora green like those of dusky-faced meadow katydids, but with brown tibias, and it is the same size as those species, but the most distinctive feature is the yellow end of the abdomen, reminiscent of the much smaller short-winged meadow katydid.

This is the best I could do on a ventral cerci shot, balancing in the leaky boots and holding the struggling critter with one hand while manipulating the camera with the other. Note the beautiful colors, and the distinctive shape of the pointed, brown-tipped cerci.

This is the best I could do on a ventral cerci shot, balancing in the leaky boots and holding the struggling critter with one hand while manipulating the camera with the other. Note the beautiful colors, and the distinctive shape of the pointed, brown-tipped cerci.

The song is not so loud that I can expect to hear it from more than 15-20 feet away, but the fact that I can hear it unaided will be a huge help in future searches. The nimble meadow katydid’s adaptation to beds of emergent plants in deeper water means that its main threat probably is not invasive wetland plants but rather the mechanical disruption of habitat by power boats, waves bouncing off sea walls, and the like.

I was out of time. Grand Mere State Park still holds promise, and I look forward to returning next year.

 

Sarett Nature Center

by Carl Strang

Sarett Nature Center is located in northern Berrien County, Michigan. It has some high quality habitats, in particular a good sized fen and some upland forest. Glimpses of the facility’s education program that I got when I visited there last week pointed to high quality in that service, as well. Sarett’s singing insects provided a couple highlights worth sharing here.

While checking out a restored prairie and its adjacent tree line, I encountered a Forbes’s tree cricket laying eggs.

The female arched her body so as to bring her ovipositor in perpendicular to the sassafras stem. The line of eggs was around 3 inches long.

The female arched her body so as to bring her ovipositor in perpendicular to the sassafras stem. The line of eggs was around 3 inches long.

The fen was rich in sedges and other native plants.

A boardwalk provides access to the fen’s interior.

A boardwalk provides access to the fen’s interior.

Through the SongFinder I heard an unfamiliar insect song, a rapid tapping sound.

The singers proved to be black-sided meadow katydids.

The singers proved to be black-sided meadow katydids.

When I have encountered this species before, its song was overwhelmed by those of black-legged meadow katydids. Those were few in the fen. It became clear that the black-sideds were concentrated in portions of the fen that had coarse-stemmed red-osier dogwoods or broad-leaved cattails.

I left Sarett satisfied with my experience there, but a couple hours of light remained, and the day’s big highlight was still ahead…

 

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