Even More Melodious

by Carl Strang

Relatively little has been published about melodious ground crickets (Eunemobius melodius). These tiny insects with their beautiful trilling songs first revealed themselves to me at Indiana Dunes State Park in 2012.

Melodious ground cricket

They were abundant in an open, low wet forest associated with the shrub swamp that occupies a central position within that park. The ground there has relatively little vegetation beneath the trees, with abundant rotting logs on the ground, mosses, ferns, and some other vascular plants, but much ground with nothing but wet leaf litter. On another day, I heard a few melodious ground crickets in a similar habitat at Warren Woods in Berrien County, Michigan, and in a shrub swamp in Warren Dunes State Park, also in Berrien. There the matter rested until I heard a single individual in a bottomland forest in Tippecanoe River State Park, Pulaski County, Indiana, late last year. That observation planted an idea: perhaps this species is more abundant than I realized. Flood plain forests, resembling that original site at Indiana Dunes State Park, can be found along all the major rivers in the Chicago Region. Could melodious ground crickets be found in all those places? That set the stage for one of this year’s goals.

I first tested the idea on August 11 at the Momence Wetlands, a state-owned property in Kankakee County, Illinois. As I walked into this Kankakee River floodplain forest, I was struck by its similarity to other places where I have found melodious ground crickets, and before long I began to hear them singing. As I have come to expect, they were on the ground, in or close to rotting logs. I made sound recordings to analyze for confirmation, but the contrast between their songs and those of Say’s trigs (Anaxipha exigua), which were singing nearby up in tall herbaceous vegetation, made the identification clear in my mind before the analysis later confirmed it. According to the comprehensive database used to build the species’ maps for the Singing Insects of North America website, this was the first time the melodious ground cricket was documented in Illinois.

That same day I found them on both sides of that same river in Indiana, adding Lake and Newton County records. With that success in hand, I put some time into searching for melodious ground crickets in other counties and river systems. So far, I have found them along the Kankakee River in Starke and LaPorte Counties, and the Tippecanoe River in Fulton and Marshall Counties, all in Indiana. The significance of this is that the Kankakee River flows west to co-form the Illinois River and flow into the Mississippi. The Tippecanoe joins the Wabash River, flowing south to the Ohio River. Though the Yellow River (a tributary of the Kankakee) and Tippecanoe both cross through Marshall County, their watersheds are well separated by miles of dry moraines and sandy areas. The crickets were absent from bottomland areas that recently had flooded, but rotting logs in slightly more elevated portions consistently held singing crickets.

In Illinois, I found melodious ground crickets in Will County around the confluence of the Kankakee and Des Plaines Rivers, and upstream from there along the Des Plaines in my home county of DuPage. That is as far as I will go with this pursuit as the season winds down, but I expect to add more counties to the list next year. I conclude that at least in this limited but widespread habitat type, the melodious ground cricket can be sought throughout the southern portion of the Chicago region. Here is the map to date:

Map showing counties where I have found melodious ground crickets in the Chicago region, updated with 2017 observations.

I close this post with a couple sound recordings, both made at the Des Plaines Riverway Forest Preserve in DuPage County, Illinois, on September 6. The first, of a melodious ground cricket:

The second recording is the song of a Say’s trig:

Ground crickets, as the name suggests, sing from the ground (or, in the melodious ground cricket, sometimes from within a rotting log). Trigs sing from perches up in the vegetation. In this pair of recordings, the statistics quantify the differences you should be able to hear. The melodious ground cricket had a lower-pitched song, at 5.11 kHz, and a slower pulse rate, at 22/second. The Say’s trig’s corresponding numbers are 6.10 kHz and 31/second. The temperatures near the two singers bring out the contrast even more, the elevated trig at 17.7C and the ground cricket at 19C (i.e., if the trig had been singing at the ground cricket’s temperature, one would expect the dominant frequency and the pulse rate both to be even higher). The two species, as I mentioned above, often occur close to one another, making this difference worth noting.

 

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Early Season Survey: Berrien County

by Carl Strang

I took last week as a vacation to do some early season singing insect surveying across the Chicago region. Monday took me to Berrien County, Michigan, which I had searched only once before late in the season. In addition to seeking the few species active this early, I wanted to scout some sites for their later-season potential. My first stop was Galien River County Park.

The start of the trail looked promising. The forest proved to be of good quality. I listened for northern wood crickets, but none were there.

The start of the trail looked promising. The forest proved to be of good quality. I listened for northern wood crickets, but none were there.

The park’s most spectacular feature is a wonderful canopy walkway, which ends in a platform overlooking the Galien River and moderate quality wetlands.

The park’s most spectacular feature is a wonderful canopy walkway, which ends in a platform overlooking the Galien River and moderate quality wetlands.

The walkway takes you into the upper canopy. I’m looking forward to getting back some evening later in the season.

The walkway takes you into the upper canopy. I’m looking forward to getting back some evening later in the season.

The marsh is cattail dominated, with reed canary grass invading, but has some potential for wetlands singing insects.

The marsh is cattail dominated, with reed canary grass invading, but has some potential for wetlands singing insects.

Another site new to my experience was Mud Lake Bog. Bogs are few in the region, so I had high hopes.

I was not disappointed. A boardwalk winds a good length through a high quality bog.

I was not disappointed. A boardwalk winds a good length through a high quality bog.

There was plenty of sphagnum moss, so I expect to add Berrien to the short list of counties in the region still harboring sphagnum ground crickets.

There was plenty of sphagnum moss, so I expect to add Berrien to the short list of counties in the region still harboring sphagnum ground crickets.

A final stop for the day was Warren Dunes State Park. Spring field crickets were common in the more sheltered spots of the outer dunes.

A final stop for the day was Warren Dunes State Park. Spring field crickets were common in the more sheltered spots of the outer dunes.

An early season delight is to spot the glowing yellow of hairy puccoons.

An early season delight is to spot the glowing yellow of hairy puccoons.

No need to enhance the color in a photo of these beauties.

No need to enhance the color in a photo of these beauties.

Though the day produced only 2 county species records, it was delightful for visits to familiar sites and the promise of the new ones.

 

Sights Along the Way

by Carl Strang

It has been a memorable few weeks. This year I took the bulk of my vacation time in the heart of the singing insect season, mid-August to mid-September, and spent most of it traveling around the 22-county area, from southwest Michigan to southeast Wisconsin, where I am seeking the 100 species of cicadas, crickets, katydids and singing grasshoppers that occur (at least potentially) there. This travel took me to many memorable places.

High quality forests are scattered around the region. Sanders Park, Racine County, Wisconsin.

High quality forests are scattered around the region. Sanders Park, Racine County, Wisconsin.

I didn’t spend a lot of time in the forests, however, much as I love them. Most singing insects live in more open habitats.

The dunes around the edge of Lake Michigan provided some of the most open habitats. Warren Dunes State Park, Michigan.

The dunes around the edge of Lake Michigan provided some of the most open habitats. Warren Dunes State Park, Michigan.

One of my favorite areas was Miller Woods at the western end of the Indiana Dunes National Lakeshore.

The trail leads through savanna and past wetlands. Here it crosses a former rail foundation.

The trail leads through savanna and past wetlands. Here it crosses a former rail foundation.

The Miller Woods Trail eventually skirts a large pond at the edge of the dunes, and reaches the beach.

The Miller Woods Trail eventually skirts a large pond at the edge of the dunes, and reaches the beach.

Wetlands included Bluff Creek in the Kettle Moraine State Forest, Walworth County, Wisconsin.

The water was beautiful and clear, flowing over stones and gravel.

The water was beautiful and clear, flowing over stones and gravel.

A fen-like wetland, bordering the creek, contained species such as the fringed gentian.

A fen-like wetland, bordering the creek, contained species such as the fringed gentian.

Sure, I was paying attention to species other than singing insects. At the Houghton Lake Nature Conservancy property in Marshall County, Indiana, I encountered a couple interesting ones.

A Chinese mantis nymph stalked through the wetland vegetation.

A Chinese mantis nymph stalked through the wetland vegetation.

This gray treefrog snoozed in a leaf bed.

This gray treefrog snoozed in a leaf bed.

The most extensive prairie I encountered was in the Bong Recreation Area, Kenosha County, Wisconsin.

Its size alone speaks to the potential in this restoration project.

Its size alone speaks to the potential in this restoration project.

For now I will close with the sunset on my last evening at Bong.

The sunset was a beautiful prelude to a rainy evening in camp.

The sunset was a beautiful prelude to a rainy evening in camp.

The singing insects of course were the focus of all this travel. I’ll share images of some of them in future posts.

Hoppers

by Carl Strang

Some singing grasshopper species mature late in the season, and I have begun to encounter a few. Their identification is based on fairly clear anatomical characteristics, but good views (photos or a specimen in hand) are needed of several body parts viewed from precise angles. The songs don’t help much. Members of the band-winged grasshopper subfamily rattle their wings in flight, and members of the stridulating grasshopper subfamily rub their hind legs over the folded wings to make sounds that are essentially identical. Through trial and error I now know that I especially need: clear dorsal and lateral views of the thorax; the color and patterning of the tibias and inside surfaces of the femurs; and, usually, the color and patterning of both the front and hind wings.

The femur and tibia colors appear to be significant to the grasshoppers themselves. When a seaside grasshopper lands close to a member of the opposite gender, the two begin a stereotyped leg-lifting display.

Two seaside grasshoppers flash their colors to one another. Warren Dunes State Park, Michigan.

Two seaside grasshoppers flash their colors to one another. Warren Dunes State Park, Michigan.

The leg colors are hidden in the usual resting posture, which proves how well camouflaged these insects are. Seaside grasshopper, Indiana Dunes State Park.

The leg colors are hidden in the usual resting posture, which proves how well camouflaged these insects are. Seaside grasshopper, Indiana Dunes State Park.

The hind wing colors of the band-winged grasshoppers usually are folded out of sight. The yellow base of the seaside grasshopper’s wing looks brighter when the insect flies than it appears when fully expanded in the hand.

The hind wing colors of the band-winged grasshoppers usually are folded out of sight. The yellow base of the seaside grasshopper’s wing looks brighter when the insect flies than it appears when fully expanded in the hand.

Seaside grasshoppers are strongly associated with the Lake Michigan beaches in our region. I found more members of this subfamily in a waste area in Cook County, Illinois.

Two or three band-winged grasshopper species were here, the Carolina grasshopper and one or two with yellow wing bases.

Two or three band-winged grasshopper species were here, the Carolina grasshopper and one or two with yellow wing bases.

Some of them looked like this. Again, note the good camo.

Some of them looked like this. Again, note the good camo.

This was part of my learning process. I caught one of the grasshoppers and took some photos in the hand, but failed to get a crucial piece of information.

I was going to call this one a mottled sand grasshopper, but without a clear profile of the thorax I couldn’t be sure. Now that I have had a chance to study these photos a little more, I think this was an inland population of the seaside grasshopper.

I was going to call this one a mottled sand grasshopper, but without a clear profile of the thorax I couldn’t be sure. Now that I have had a chance to study these photos a little more, I think this was an inland population of the seaside grasshopper.

I need to go back to that site some time, not only to confirm the identity of this species, but also to check some individuals that had orange rather than yellow tibias, and may represent a different species.

Finally, there was a different-looking band-winged grasshopper at Indiana Dunes National Lakeshore.

Grasshopper colors can vary considerably with habitat, as they are strongly selected to match local background patterns. I can find no match for this color pattern in any of my references. This individual was on an old railroad bed in a savanna.

Grasshopper colors can vary considerably with habitat, as they are strongly selected to match local background patterns. I can find no match for this color pattern in any of my references. This individual was on an old railroad bed in a savanna.

I will need to go back for this one, too, but again with further study, focusing mainly on the shape and proportion of the thorax, wings and head, I am tentatively identifying it as a Boll’s grasshopper. If I’m correct, this is a dramatic example of how a species can vary from place to place. Compare the above photo to the next one.

Here is a Boll’s grasshopper at Illinois Beach State Park. This one is separated from the previous individual by only two counties’ distance.

Here is a Boll’s grasshopper at Illinois Beach State Park. This one is separated from the previous individual by only two counties’ distance.

These grasshoppers are fun. I hope to find more, as many more species in the two singing subfamilies have been found in the region historically.

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