Closing the Book on Green-winged Cicadas

by Carl Strang

The green-winged cicada (Diceroprocta vitripennis) provides a favorite example of why I need to include 22 counties in my survey of Chicago-region singing insects. I checked a final two locations recently, and am satisfied that I have a good sense of where this species occurs.

Black dots indicate counties where green-winged cicadas can be found.

The most important habitat feature appears to be sandy soil. Cicadas spend most of their lives underground, so it is not surprising that soil texture can influence their distribution. The mapped area contains two sandy regions: the dunes edge of Lake Michigan in Indiana and Michigan, and the Kankakee River corridor. The cicadas do not, however, extend throughout those soil areas. They thin out quickly in western Starke and Pulaski Counties, Indiana, and do not reach into the sand soil portions of St. Joseph and Marshall Counties.

Green-winged cicadas had an important lesson for me this year. Previously I had thought of them as a woodland species, having observed them singing in trees, especially in black oak savannas and woodlands. Then I came to this spot in Newton County, Indiana:

A single large cottonwood and two smaller trees towered above clusters of shrubs.

I was surprised to step out of the car, expecting to focus on sand-soil grasshoppers, and hear green-winged cicadas singing. As I approached them I found that they were singing, not from the big trees, but from plants no taller than me, winged sumacs and a small black oak.

This discovery provided a welcome opportunity to photograph live green-winged cicadas.

They were very alert, and required a glacially slow stalk.

Feel free to wave back. No one is watching.

I also found a site in Jasper County where the cicadas were singing from shrubs. They can be fairly loud at close range, but they are small, with bodies not much more than an inch long, so the song quickly attenuates over distance. It seems to carry better when the singing perch is in a tree. The song is a distinctive pulsing rasp:

These early season cicadas sing mornings to mid-afternoons, and largely are done by the end of July.

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The Currency I Work in

by Carl Strang

The main focus of my research these days is traveling through the 22 counties of my survey area, seeking the singing insects that live in the Chicago region. I am building on previous years’ work, filling gaps in range maps. The currency I work in thus is county records. There are around 100 species known to have occurred here, and so the maximum total would be 2200 county records. This is not going to be the eventual result, however, because many of the species live only in limited areas within the region. For instance, last week I closed the book on the green-winged cicada.

This distant photo is the best I have so far of a green-winged cicada.

This distant photo is the best I have so far of a green-winged cicada.

I do not expect to find green-winged cicadas beyond the 10 marked counties.

I do not expect to find green-winged cicadas beyond the 10 marked counties.

They occur only in sand soil woodlands within the region. Though other counties have some areas with sand soils, I have searched them and failed to find the species. Their numbers clearly diminish at the periphery of their range. Four of these county records have been from this year.

Other species are widespread, and ultimately I expect to find them in every county. Two early season species now have filled maps as a result of my travels this spring and early summer: Roesel’s katydid, and gladiator meadow katydid.

Roesel’s katydid

Roesel’s katydid

There is learning involved in the process. Some species which historically have occurred in the area I have not yet found. Others I have found once or twice. At some point I become familiar enough with a species that I know how to find it. Then I seek it out in the appropriate habitat in the counties where I haven’t found it. The sulfur-winged grasshopper is an instructive example. This year I made a push to complete the map for this early-season species. Though I ran out of time before the end of its season, I got close.

Updated map for sulfur-winged grasshopper

Updated map for sulfur-winged grasshopper (open circles represent historical records)

Next year I will check sandy sites in two of the counties in Wisconsin, LaPorte County in Indiana, and Berrien County in Michigan. Though I suspect that sulfur-winged grasshoppers occur in every county, they are very few and hard to find away from sand soils. Though my own county of DuPage is marked, it is a clay soil county and over the many years I have lived here I have encountered fewer than 5 sulfur-wings in DuPage.

A final example is the northern bush katydid. I had heard two of these in the early summer of 2007, in woodlands in my county. I had heard none since. But a few days ago I went back to one of those sites and tried listening at night with the SongFinder, a device which reduces the pitch of sounds. Lo and behold, I discovered that Parson’s Grove at Danada Forest Preserve has a lot of northern bush katydids. I hadn’t realized that it was the deterioration of my hearing with age that had prevented my detecting them. Now I anticipate finding them in every county in the region.

So far this year I have accumulated 47 county records. I expect to end up with more than last year’s 174.

Short-winged Toothpick Grasshopper

by Carl Strang

The most fruitful recent singing insects search was at the Kankakee Sands preserve in Kankakee County, which has become one of my favorites for species that affiliate with sand-soil habitats. The June 28 visit yielded 3 county records, two of which were of familiar species, Roesel’s katydid and green-winged cicada.

Grasshoppers were building up their diversity at the site. Sulfur-winged grasshoppers still were going, and the season’s first mottled sand grasshopper also flashed his wings.

This was by far the earliest I have found this sand-soil specialist.

This was by far the earliest I have found this sand-soil specialist.

Then in the prairie beyond the savanna I started to hear the zuzz-zuzz-zuzz of stridulating grasshoppers. I had a hard time getting a look at who it might be. Eventually I saw a possible candidate.

This grasshopper has a somewhat slanted face, and color markings reminiscent of stridulating grasshoppers in genus Orphulella.

This grasshopper has a somewhat slanted face, and color markings reminiscent of stridulating grasshoppers in genus Orphulella.

Study of the photos, however, led to an identification as the meadow purple-striped grasshopper, Hesperotettix viridis, in the non-singing spur-throated grasshopper group. As I waded through the grasses I flushed out a couple really odd grasshoppers that begged to be photographed.

The blade-like antennas, subtle striping pattern, and especially the gangly skinniness of the critter were distinctive.

The blade-like antennas, subtle striping pattern, and especially the gangly skinniness of the critter were distinctive.

They reminded me of high school basketball players whose growth spurts have given them impressive height, but whose strength and coordination have some catching up to do. Though I saw and photographed only the minute-winged females, my identification and study convinced me that these were the stridulators. The short-winged toothpick grasshopper is well named, seeming to be constructed of toothpicks. It is a member of the slant-faced stridulating subfamily, and is described as being a frequent singer. The species, also known by the more mundane name of bunchgrass grasshopper (Pseudopomala brachyptera), now is removed from my hypothetical list for my survey region.

Return to J-P

by Carl Strang

A few hours of singing insect searching over the weekend produced 8 county records (across 3 counties), and some photos I’d been hoping to get. High on the list of priorities for the latter this year was the green-winged cicada, Diceroprocta vitripennis. I found a number of them singing Saturday at Jasper-Pulaski State Fish & Wildlife Area in Indiana. Finding a singing cicada up in a tree is a challenge when it can be done at all. The good part is that I found one.

The less than great part is that the only line of sight was from a distance and through a canopy hole, so I will hope for a better opportunity at another time.

The less than great part is that the only line of sight was from a distance and through a canopy hole, so I will hope for a better opportunity at another time.

I also heard one of that species singing Sunday at Braidwood Dunes in Will County, my first Illinois location. So far all have been in black oak sand savannas.

Back at J-P, I was able to catch a sulfur-winged grasshopper, so as to get a photo of the bright yellow hind wing.

If anything, the yellow was more intense than the photo indicates.

If anything, the yellow was more intense than the photo indicates.

The critter stayed put when I released it, making a portrait possible.

Though study of reference material confirmed the ID, this one was much paler than the individual I photographed within 50 feet of this location last year.

Though study of reference material confirmed the ID, this one was much paler than the individual I photographed within 50 feet of this location last year.

That 2013 hopper may have had the more typical color pattern. I saw its twin at Braidwood Sunday.

That 2013 hopper may have had the more typical color pattern. I saw its twin at Braidwood Sunday.

Nearby at J-P was a pair of grasshoppers that begged to be photographed. They do not belong to either of the singing subfamilies of grasshoppers, but they were attractive to look at.

These appear to be narrow-winged grasshoppers, Melanoplus angustipennis.

These appear to be narrow-winged grasshoppers, Melanoplus angustipennis.

As I drove out of J-P, I was arrested by this group of plants beside the road.

Brilliant red flowers topped the tall stems.

Brilliant red flowers topped the tall stems.

They appear to be targeting hummingbirds as pollinators.

They appear to be targeting hummingbirds as pollinators.

The foliage accounts for the odd name (for an herbaceous plant) of standing cypress.

The foliage accounts for the odd name (for an herbaceous plant) of standing cypress.

Gilia rubra is native to the southern states, but has established some colonies of escapes from cultivation in the sand counties of northwestern Indiana.

Green-winged Cicada Update

by Carl Strang

I have made a correction to yesterday’s post on green-winged cicadas. I always check my posts when I get to work, to make sure nothing is lost in the translation to another computer. In the process of checking links, I went to the Cassin’s 17-year cicada portion of the Michigan cicada website. There I saw something I hadn’t noticed before, mention of “Court II” and “Court III” signals. The Court III signal is produced by a male cicada as he connects with a female for mating.

Cassin’s 17-year cicadas, mating pair

Cassin’s 17-year cicadas, mating pair

When I played the Court III signal recording, it proved to be what I had attributed to green-winged cicadas in 2007. That both corrected my impression of Diceroprocta in DuPage County, and removed any confusion about my observations in 2013.

Sound Ideas: Green-winged Cicadas

by Carl Strang

One of the singing insects I have been seeking for several years in the Chicago area is the green-winged cicada (Diceroprocta vitripennis). Some references have suggested that this is an early-season species, and I thought I heard them in June of 2007 (the brief regular buzzes in the following recording, with Cassin’s 17-year cicadas in the background):

Those sounds were very similar to the cooler-temperature recording of Diceroprocta at the University of Michigan’s cicada website, though a little slower (the temperature was about 10 degrees cooler). The problem was that the periodical cicadas were in their peak year and season at the same time, and the identification was ambiguous because I couldn’t entirely rule out the possibility that these were Cassin’s 17-year cicadas warming up. Returns in subsequent years to places where I heard those sounds failed to turn up a repeat performance. Now I find that those actually were “Court III” signals of the Cassin’s cicadas, produced by the male as he connects with a female for mating.

During my survey work this past field season, I finally heard green-winged cicada songs on July 29, first at Willow Slough Fish and Wildlife Area, then at Jasper-Pulaski, both in Indiana (a scissor-grinder cicada song is in the background at the start):

Oak woodlands on sandy soils, including this one at Jasper-Pulaski Fish and Wildlife Area, are where I heard this song.

Oak woodlands on sandy soils, including this one at Jasper-Pulaski Fish and Wildlife Area, are where I heard this song.

These were a match for the warmer-temperature song at the University of Michigan website (the temperature was cooler for my recording, but the insect may have had a warm perch in the sun; I didn’t see it). That day was the extent of my experience with this species, though, so more observations are needed to get a better handle on the abundance, distribution and habitat of green-winged cicadas in the Chicago region.

Return to Newton and Jasper

by Carl Strang

On Monday I returned to Newton and Jasper Counties, Indiana, to survey for singing insects that had emerged since my earlier visits there (Newton County was the site of the bioblitz last year; I went to a new site this time, the Willow Slough State Fish and Wildlife Area). In Jasper County I went back to the Jasper-Pulaski Fish and Wildlife Area, and was especially interested in revisiting the savanna and sand prairie.

The savanna-sand prairie site at the time of my first visit.

The savanna-sand prairie site at the time of my first visit.

The most exciting find was an unfamiliar insect singing loudly from the black oak woodlands of both sites in the early to mid-afternoon. Its song was a series of quick buzzing sounds, as though a sword-bearing conehead (which sings at night) woke up way early and got hold of a megaphone. With that volume at that time of day well up in the trees it had to be a cicada, and when I later referred to sources and listened to reference recordings it was clearly the green-winged cicada, Diceroprocta vitripennis. This is a species I thought I might have heard in DuPage County at the time of the periodical cicada emergence in 2007, but the songs were difficult to separate from the loud Magicicada choruses, and I have not heard it since, until Monday. I did not see one, but hope to get a photo in the future.

Otherwise the singing insects were familiar, though I did pick up a number of county records and heard a few species singing for the first time this year.

Also, a very large, interesting looking grasshopper flew up from the sand prairie and landed on a tree after a graceful flight on its long wings.

It was noticeably larger than the Carolina grasshopper, the most common large grasshopper in the region.

It was noticeably larger than the Carolina grasshopper, the most common large grasshopper in the region.

The color pattern, behavior and habitat point to the obscure bird grasshopper (Schistocerca obscura), not a singing insect but an interesting attention-grabber nevertheless.

Cicada Update

by Carl Strang

Periodical cicadas in small, scattered numbers have continued to appear in a large part of DuPage County. Steve Bailey, who conducts bird surveys for the state, also has heard them in parts of Grundy and southern Cook County. So far nearly all have been singing the cassini song type, except for one septendecim-like singer reported from Fullersburg Woods Forest Preserve by Naturalist Leslie Bertram.

There are so few that prospects for reproductive success are dim.

This is the expected fate for nearly all of these vulnerable individuals, to be eaten by birds, their wings plucked off and dropped to the ground.

I witnessed such a predation event myself at Mayslake Forest Preserve. A cicada got in maybe four songs before a robin flew straight to it. The insect got out an alarm squawk, then all was still.

In an earlier post I speculated about what was going on with these cicadas, which had been quiet the previous two years. A suggestion by WBEZ radio news director and nature enthusiast Brian O’Keefe reminded me of similar ideas expressed in the scientific literature when cicadas appear outside their brood’s normal area: perhaps these were transported from the southern brood XIX range in the root balls of nursery stock. That certainly could account for the ones in residential areas and in portions of forest preserves adjacent to private lands. I checked with the Forest Preserve District of DuPage County’s nursery staff, however, and none of our tree plantings in the past 13 years have come from so far south. Some of these cicadas are half a mile or more from the nearest preserve boundary. A little mystery therefore remains, but I have concluded that my time would be better spent in other directions.

Incidentally, while documenting these scattered emergences I was listening for green-winged cicadas (Diceroprocta vitripennis), another spring species which I believe emerged in small numbers in 2007. Their buzzings were largely covered by those of periodical cicadas, however, and the only hard evidence was a single wing, like the one in the photo above, but with green rather than red veins. Some of the literature suggests a 4-year periodicity for Diceroprocta, but I have encountered none in the places I thought I was hearing them in 2007.

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