Forsythe Woods

by Carl Strang

Last week I provided a field training on singing insects for interpretive naturalists in Will County, a group organized the Nina Baki of that county’s Forest Preserve District. We started at Braidwood Dunes, finding the same species that I encountered in my first visit there a year ago, plus a few more. After an enjoyable dinner at a nearby restaurant, four of us went on to Forsythe Woods Forest Preserve to see what singing insects would emerge in the darkness. We were gifted with some good displays by several species, including the first broad-winged tree crickets I have heard singing this year.

The raspberry colored top of the head and bases of the antennae distinguish this species.

While I was attempting to get clear photos of that tree cricket, someone noticed another insect near it. This one arrested our attention. The greater part of an inch long, its broad face and extremely long antennae, its reddish color, and the apparent lack of wings contrasted it with everything we had seen that day. It was tempting to call it a nymph, but I had a hunch that this was a cricket belonging to a wingless group.

Fortunately this odd insect posed long enough for a clear photo.

The next day I went to the BugGuide website, a generally reliable source of insect images, and it and other web references identified this as a Carolina leaf-roller. This is a truly odd cricket, the only member of its family (Gryllacrididae) north of the tropics. The family is mainly a southern hemisphere group, with many of the several hundred species found in Australia. Carolina leaf-rollers spend the day sheltered in a leaf they roll up and glue closed, or sometimes in the inflated pod of a bladdernut bush. At night they emerge to prey on aphids. They are not singing insects, indeed being wingless, but are fascinating creatures nevertheless.

Fork-tailed Bush Katydid

by Carl Strang

A final gift at Indiana Dunes State Park was of fork-tailed bush katydids singing near the nature center after dark, in the absence of greater angle-wings. Reference recordings of the two species’ songs sound very similar, the single brief buzz of the fork-tailed resembling the alternate song of the greater angle-wing (the latter species also produces an unmistakable ticking sound). Greater angle-wings are very common in northeast Illinois woodlands and residential neighborhoods, but fork-taileds are less so, leaving me wondering if I might confuse them in my surveys. A fork-tailed at the State Park resolved this dilemma.

He was singing in a small tree, just a few feet above the ground.

The fork-tailed’s song is not nearly as loud as the greater angle-wing’s (it is a noticeably smaller insect with narrower, more open wings). The greater angle-wing’s brief song also has a sharp, harshly rasping quality in contrast to the lisping nature of the fork-tailed’s song. Finally, greater angle-wings usually sing from high up in trees. The three fork-taileds I heard at Indiana Dunes all were within 8 feet of the ground. While phonetic renderings can be useful in some cases, I think they can only confuse in this instance: the same or similar syllables (tzip, thisp, etc.) could be used to describe either insect’s song.

Greater angle-wing

Reference recordings commonly are made of captive insects held indoors, with the microphone very close to the singing subject. This makes for a clear, isolated recording, but can produce misleading impressions, as the present case illustrates.

Marsh Conehead

by Carl Strang

My memory of the great marsh at Indiana Dunes State Park was of an extensive, grass dominated wetland. Perhaps it was once, but today it has succeeded to a shrub swamp.

A tower along one of the trails provides an overlook.

A shrub swamp is a valuable habitat, but for my purposes there are relatively few pockets of the grasses that would harbor the greatest diversity of singing insects.

Here is one such pocket along the north edge.

The drought that has dried the wetlands to a large degree no doubt also contributed to the low numbers of katydids and crickets I found in these grassy patches. One individual of interest, however, was a female conehead.

She instinctively trusted her camouflage, which allowed me to approach and catch her.

Not knowing which characteristics were essential and not wanting to kill her unnecessarily (though I did have the necessary permits), I took a series of photos.

The underside of the cone, its shape and its markings, are an important feature in conehead identification.

In many groups of katydids and crickets, ovipositor shape and size also is helpful in identifying females.

Here is the ovipositor of the female I caught.

Habitat also is helpful, in this case the marsh. Only two species of coneheads with unmarked cones are expected in marshes, the marsh conehead and the robust conehead. In this case the pinched, slightly elongate cone and the ovipositor shorter than the length of the femur point to marsh conehead. The only additional feature I should have checked was the insect’s length, a point to keep in mind for the future.

This finding, which seconds the identification of marsh coneheads that the Missouri students and I found at the nearby National Lakeshore, continues to open my eyes to the limitation of past records. Published accounts don’t show marsh coneheads this far north in Indiana. The same was true for slightly musical coneheads. Consequently I did not have either species on my hypothetical list for the region. Do these discoveries represent range extensions, or simply a mismatch between spotty past surveys of spottily distributed species? It may not be possible to say, but I have to be open to the possibility that my hypothetical list likewise may be incomplete for other groups of singing insects.

Indiana Dunes State Park Mystery

by Carl Strang

Indiana Dunes State Park is an older preserve than the National Lakeshore that surrounds it. Last week I spent a day there searching for singing insects. As was true at the National Lakeshore earlier in the month, most of the species I found were familiar, but there were a few added ones. For instance, a female rattler round-wing katydid was climbing the outside wall of the park’s nature center.

Later in the evening I heard a couple males singing nearby.

Also that evening I heard a number of jumping bush crickets. The dunes area had, as expected, gray ground crickets.

The day also brought a mystery. As had been the case at the National Lakeshore forest, confused ground crickets were common in the shaded areas, and there were a few tinkling ground crickets around the dry edges. In addition, however, in the wet-mesic forest south of the State Park’s great marsh, and extending well into the wooded margins of the marsh, a common third species was singing a clear and steady trill. It was similar in pattern, but distinctly lower in pitch and with a different tonal quality, than the Say’s trigs that were abundant in more open areas nearby.

Red oaks, ferns and deep leaf litter were characteristic of the mystery cricket’s song sites.

I remembered that the spotted ground cricket is a forest species I had not yet found, and thought that perhaps this would prove to be the solution. Later, however, when I consulted reference recordings, I was reminded that the spotted ground cricket has a pulsing trill unlike the mystery cricket’s steady song. Reviewing other possibilities, I hit upon the melodious ground cricket. The song was very close to what I heard.

The melodious ground cricket is not as well known as many other ground crickets. Edward S. Thomas and Richard Alexander first described it in 1957, and their work provides much of what has been published about it, at least in the North. They characterized it as a marsh species, but their more detailed site descriptions often, if not usually, place it among woody plants. “The majority of our specimens of melodius were secured by tearing apart a soggy, decayed log, honey-combed with insect burrows, about 20 feet from the marsh proper.” While this supports my tentative identification, at some point I will need to get back there and catch some of these crickets to make a positive determination.

Maxinkuckee Wetlands

by Carl Strang

Another area near Culver, Indiana that I wanted to check for singing insects was the Maxinkuckee Wetlands, a state conservation area. Much of it I will need to access by kayak on another occasion. My daytime visit did not produce much, but when I returned at night I was pleased to find a population of slightly musical coneheads, which I first had encountered in the previous week at Indiana Dunes National Lakeshore.

Unlike the mole cricket, as mentioned in yesterday’s post, the slightly musical conehead has a buzzing song.

Along the road edge of the property I heard a different conehead, and traced the song to a small oak.

The impressive volume of the song up close was enough to confirm the singer as a robust conehead. The dry habitat and cone free of black markings support the identification.

Maxinkuckee Wetlands is another site calling for continued exploration.

Houghton Lake

by Carl Strang

A priority site in this year’s singing insect survey work was Houghton Lake, a Nature Conservancy property near my home town of Culver, Indiana. The muck, marl and sand soils potentially support communities including wetland crickets and katydids that I have not yet found. Last week I spent an afternoon and evening walking through the site.

The property, named for this lake, is of particular interest as it hosts a population of rare massassauga rattlesnakes.

There are many smaller wet areas on the site, which is a flat postglacial lake plain. It has great botanical as well as zoological biodiversity.

For the most part I found a long list of familiar, common species.

Black-legged meadow katydids, like this female, are expected in wet areas.

As I walked the lanes I heard crickets singing in the pattern of Say’s trigs, but with a more mechanical or buzzing sound quality. I spent some time searching, because I thought they would prove to be a species I had not seen before. This effort was rewarded.

The handsome trig is one of the more beautiful singing insects in the region. They are tiny, around a quarter inch long.

Another unfamiliar sound was a rhythmic “warg warg warg” coming from a couple wet prairie areas. The song’s rhythm was like that of slightly musical coneheads, but that katydid produces a call with a distinctly buzzing quality. A comparison of recordings led me to the northern mole cricket. The mole cricket’s song is a chirp, but so deep that it is not readily characterized as such. Like the handsome trig, this was a species new to my experience. For future monitoring purposes I was pleased at how far their songs carry, and that at least sometimes they can be heard singing in the mid-afternoon.

A few conehead nymphs turned up in sweep net samples.

These probably will prove to be round-tipped coneheads, which mature later than most of their relatives.

An additional interesting insect was a great blue skimmer.

This was only the third individual of this species I have encountered.

Most of the conservative species I’d hoped to find at Houghton Lake eluded me, but I was only able to see part of the site, and I intend to return.

Chasing Coneheads 3: Slightly Musical Conehead

by Carl Strang

After finding all the slender coneheads Gideon needed, we drove around to assess the scope of their distribution at the Indiana Dunes National Lakeshore. They proved to be abundant in the Great Marsh and other places. We heard other familiar singing insects as well. Then we heard a new one at another wetland, unfamiliar to me but well known to the Missouri grad students. We stopped and found one. This was the amusingly named slightly musical conehead.

This marsh katydid has an interrupted song that to my ear has the rhythm and tempo of a snowy tree cricket but with buzzes rather than clear toned chirps.

The slightly musical conehead has the most magnificent cone structure of all the North American species.

The cone is huge, and black on the length of its underside.

To me the most amazing feature of this species is its synchronized singing. All the males in an area sing in unison. When we disturbed the one we were stalking, he paused only for a few seconds and then started up again in rhythm with other males in earshot. “They must sing,” said Gideon, who also shared the information that this species avoids spots that have other conehead species with continuous songs.

Chasing Coneheads 2: Indiana Dunes

by Carl Strang

[Note: Gideon later wrote to share his conclusion that the coneheads we collected were in fact marsh coneheads. The individuals in that population are larger than the ones he was familiar with in Missouri, and the strange gray underside of the cone also was misleading. He later found slender coneheads in another part of their range.] Gideon Ney, Nathan Harness and I reconvened at Indiana Dunes National Lakeshore. We set up camp, but then had to wait out a long afternoon rain wondering if it would stop, if an evening’s search would be any good. The rain stopped an hour before dusk, and we set out prepared to wade through tall wet marsh grasses. We stopped at a corner of the Lakeshore’s Great Marsh, and traded stories as the light faded away. We started hearing the shrill buzzes of coneheads, and began to stalk them. Some of the early ones appeared to be marsh coneheads (Neoconocephalus palustris), which Gideon and Nathan had encountered in Missouri. Then we started catching different ones, and Gideon became increasingly excited as he ticked off characteristics, ultimately concluding that these were the long-sought slender coneheads.

Slender coneheads have medium-sized cones with nearly all the underside darkly pigmented. The Nebraska conehead is similarly marked, but occurs in wooded habitat rather than marsh, and has an interrupted rather than a continuous song.

Most of the ones we found were brown rather than green.

They usually sing head down. This one I disturbed, and he froze after changing position.

Nathan also found plenty of meadow katydids to study back in the lab.

Nathan and Gideon inventory their haul.

They took live katydids back to Missouri, so they can record their songs under controlled conditions in the lab and then get detailed DNA and other biochemical analyses to compare to other conehead species.

Ultimately Gideon hopes to collect slender coneheads from several locations. This species is interesting because it occurs in scattered, separated locations from the Atlantic coast to a site in northwest Illinois. How will its population genetics reflect this indication of a storied evolutionary history?

The night had one concluding chapter, which I’ll share in the next post.

Chasing Coneheads 1: Illinois Beach State Park

by Carl Strang

Last winter I was contacted by Gideon Ney, a graduate student at the University of Missouri in the laboratory led by Johannes Schul. Their focus is the evolutionary relationships among katydids, and members of that research group have published significant analyses of coneheaded katydids, genus Neoconocephalus. One species which they had not yet studied is the slender conehead, Neoconocephalus lyristes, and Gideon found my post in this blog on that species last winter. There I mentioned my interest in finding lyristes, and we corresponded through the succeeding months as we planned our hunt for it. Gideon and another student from that lab, Nathan Harness, who is beginning a study of Orchelimum meadow katydids, came up last week. They started at Chain O’Lakes State Park in Illinois, and I joined them the next day at Illinois Beach State Park. We set up camp, did some scouting, then relaxed in the afternoon.

Gideon and Nathan enjoy the inland sea waters of Lake Michigan.

Coneheads for the most part sing after dark, and we began to drive the roads with windows and ears open as dusk deepened to night. The first conehead we found was the sword-bearing conehead, a common species of dry meadows.

The face of a sword-bearing conehead. The English name for the group refers to the structure protruding from the top of the head between the eyes. In this species the cone has a crescent-shaped black mark near the tip.

The sword-bearing conehead is named for the female’s ovipositor. Gideon caught one and held it for my photo.

Here you can see that the ovipositor extends slightly beyond the wings.

Most of the coneheads we found had unornamented cones like those of the robust conehead, which I found at Kankakee Sands last month. However, the song was not nearly as loud, and the tentative conclusion was that these belonged to a different species, the false robust conehead. We heard a good variety of singing insects, but no slender coneheads, and so made plans to shift to Indiana Dunes National Lakeshore the next day (to be continued).

July Insect Phenology

by Carl Strang

As detailed in the previous post, first flower dates were ahead of previous years by 1-1.5 weeks in July at Mayslake Forest Preserve. Insects also had been appearing early in previous months, but did this likewise continue?

In a word, yes. The 14 species I could compare between this year and last appeared a median 14 days earlier, continuing the trend (range 36 days earlier to 12 days later). The difference was only 4 days earlier than in 2010, however (15 species, range 46 days earlier to 14 days later). The largest difference was between 2012 and 2009, a median of 16.5 days earlier (14 species, range 4 to 36 days earlier). The respective differences in June were 22, 15.5 and 22 days, so there was some convergence in first appearance dates.

The black-legged meadow katydid was as representative as any species, beginning its singing 9 days earlier than in 2011, 4 days earlier than in 2010, and 18 days earlier than in 2009.

In this year of odd weather I do not know what to expect from the data for August.

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