Closing the Book on Protean Shieldbacks

by Carl Strang

The protean shieldback is the most common native predaceous katydid in the Chicago region. Because of their broad diet, they can develop quickly in the spring. They begin singing in June, the males broadcasting their extended, high-pitched rattles in open woodlands, as well as prairies with at least a little woody vegetation.

Male protean shieldback in singing posture.

At first, they begin to sing in the late afternoon from hidden locations near the ground. When it becomes dark, they climb up onto open perches, often on woody stems. As their season progresses, they begin to sing later, until a few begin at dusk and most wait until dark.

This year I learned that they are more abundant than I had realized. I need the SongFinder, a pitch-lowering electronic device, to hear most of them. With that final lesson, I sought them out in portions of my 22-county Chicago region where I had not found them before. That mission was successful, the final 15 counties resulting in some late-night returns home. At this writing, they still are going strong.

Recent Travels: Singing Insects

by Carl Strang

Though my main research focus is singing insects, I don’t end up photographing them much, as I am listening for them rather than looking for them. Sulfur-winged grasshoppers continued to be an early-season focus.

Though I added several more county records for the species, there was not additional range in their color variation. This female was at Cook County’s Bluff Spring Fen.

Though I added several more county records for the species, there was not additional range in their color variation. This female was at Cook County’s Bluff Spring Fen.

Here is a typical dark male, Illinois Beach State Park.

Here is a typical dark male, Illinois Beach State Park.

Not much different, this male was around the corner of Lake Michigan at Indiana Dunes National Lakeshore.

Not much different, this male was around the corner of Lake Michigan at Indiana Dunes National Lakeshore.

Only 8 species of singing insects could be found at Goose Pond. There will be many more there later in the season.

Green-striped grasshoppers still were displaying, but their days are numbered.

Green-striped grasshoppers still were displaying, but their days are numbered.

Spring field crickets seldom come into view. This female was a challenge to photograph as she crawled among the grasses.

Spring field crickets seldom come into view. This female was a challenge to photograph as she crawled among the grasses.

This katydid nymph climbed up onto the sheet illuminated by the UV light. I am reluctant to say which conehead species she might be.

This katydid nymph climbed up onto the sheet illuminated by the UV light. I am reluctant to say which conehead species she might be.

The season seems barely begun, but already I am closing the book on two species.

The Vermont Cemetery Prairie Preserve in Will County reportedly is one of the few places in the Chicago region which still harbors prairie cicadas. They were done, however, by the time I got there on June 26.

The Vermont Cemetery Prairie Preserve in Will County reportedly is one of the few places in the Chicago region which still harbors prairie cicadas. They were done, however, by the time I got there on June 26.

I have just 3 sites to check next year as good candidates for persisting prairie cicada populations. Protean shieldbacks also apparently are done. I added only 3 county records for them in their brief 2016 season. This was a wakeup call, and I will need to get on my horse right away when they start next year.

 

First SFC’s

by Carl Strang

On Sunday afternoon, during a bike ride through Fermilab, I heard the first spring field crickets of the year. They had just begun, as there were only 3 of them. This is the third earliest date I have heard them in DuPage County, a little surprising given the late spring, though the deep snow that covered the ground most of the winter certainly provided the nymphs with protection. If a larger population survived, some statistical outliers could be starting up earlier than otherwise would be the case.

Cheating a little here: this is a fall field cricket female, but that species is physically identical to its spring sibling species.

Cheating a little here: this is a fall field cricket female, but that species is physically identical to its spring sibling species.

Apart from such uncommonly encountered critters as sulphur-winged grasshoppers and spring trigs, the next common singing insects to mature should be the predaceous katydids (Roesel’s katydid and the protean shieldback), and gladiator meadow katydids. By then I hope that the spring field crickets will have built numbers to the point where I can finish my county survey of their distribution.

Sound Ideas: Early Season Katydids

by Carl Strang

The start of the singing insect season still is a couple months away, but among the early species will be the three katydids I am featuring today. They are relatively hardy, hatching very early in the spring and developing quickly. Two of them, Roesel’s katydid and the protean shieldback, are known as predaceous katydids, and their dietary focus on animals is what allows them to get going so early. The gladiator meadow katydid is the earliest of its species group to hatch, and so the earliest to begin singing. The meadow katydids are generalists, and the gladiator probably has a greater proportion of animal foods in its diet than the others. Roesel’s katydid is a European species, introduced in the Montreal area and spreading south, east and west from there.

Roesel’s is the only katydid in the Chicago area with a color pattern anything like this.

Roesel’s is the only katydid in the Chicago area with a color pattern anything like this.

Its song is a long, fast, constant buzz:

I am at an age where I have a little more difficulty hearing this one each year. The pitch rises with temperature, and on a hot mid-day I now need the SongFinder pitch-altering device to hear individuals that are audible in the morning and late afternoon.

The protean shieldback, like Roesel’s katydid, is a species of the meadows, but also is common in brushy areas and open woodlands.

Protean shieldback female. This is a relatively heavy-bodied katydid

Protean shieldback female. This is a relatively heavy-bodied katydid

Its song is an extended buzz, but has much more of a slower, rattling quality than Roesel’s song.

It is not as loud as it may seem from the recording, but is not really difficult to hear. The protean shieldback begins singing in mid- to late afternoon, and continues into the night.

The gladiator meadow katydid is similar in appearance to other large meadow katydids.

This photo shows why the meadow katydids once were known as “long-horned grasshoppers.”

This photo shows why the meadow katydids once were known as “long-horned grasshoppers.”

The gladiator meadow katydid’s variation on the generalized tick-and-buzz meadow katydid song pattern de-emphasizes the tick portion. I often don’t notice ticks at all, though they may be softly produced more often than I suspect, as in the following recording:

The buzz is similar in quality to the protean shieldback’s song, but it is shorter in length, rhythmically produced, and the volume rises at the end.

Early Singing Insects

by Carl Strang

To this point in the season I have heard singing males of 10 insect species in northeast Illinois. All but one began earlier than in any of the years from 2006 to 2011. This is consistent with more general insect phenology this year, and is attributable to a mild winter and a warm March which heated the soil earlier than usual. The only species with a later starting date was the spring field cricket, a species I usually hear first while running or bike riding, activities my back trouble prevented during the critical time period. And yet, despite that limited mobility, I have recorded dates for the other 9 species that ranged 5-22 days earlier than in any previous year (4 of the previous records were in 2007, 5 in 2010, 1 last year; they add up to 10 because of a tie). The only other case perhaps worth singling out was the broad-winged bush katydid, 22 days earlier than last year’s previous record. This species is not abundant or widely distributed, and I suspect it has a longer, earlier season than I have realized before. I should make some effort in future years to get a better handle on its starting and ending dates.

Broad-winged bush katydid

For those who may be interested, here are all the first song dates this year so far. Greenstriped grasshopper 3 April, 17 days earlier than the previous record. Spring field cricket 25 May, 20 days later. Roesel’s katydid 29 May, 11 days earlier. Protean shieldback 5 June, 7 days earlier. Linne’s cicada 14 June, 12 days earlier. Gladiator meadow katydid 14 June, 7 days earlier. Dog day cicada 15 June, 5 days earlier. Scissor-grinder cicada 19 June, 13 days earlier. Broad-winged bush katydid 23 June, 22 days earlier. Lyric cicada 24 June, 6 days earlier.

Mayslake Insect Phenology July

by Carl Strang

Though I was at Mayslake Forest Preserve less in July than in June, I was able to note a larger number of new insect species appearances for the year. Among the 18 species for which I had 2009 first sightings to compare, the range was 30 days later than last year to 83 days earlier, with a median of 12 days earlier. This result continues the pattern observed so far for both insects and flowers this year, resulting from 2010’s being so much warmer than 2009.

I also added five new species to Mayslake’s insect list: viceroy and red-spotted purple butterflies (above photo of the latter species at Fullersburg, 2006), Halloween pennant and spot-winged glider dragonflies, and protean shieldback (a predaceous katydid).

A Week of Firsts

by Carl Strang

The past week brought the true beginning of the singing insects season. Though a full work week and other obligations filled my time, I was able to take advantage of what I have learned in past seasons to make some observations that were valuable to me.

For instance, last year I finally nailed down features of the two-spotted tree cricket’s song that removed my earlier uncertainty. The breakthrough came when I found this male, who had chewed a hole in a grape leaf to create a baffle that amplified and/or directed his song.

Finally seeing one of his kind in action, I was able to define the song of that species by the irregular length of its trills, some reaching 7 seconds’ length or more, the spaces between trills being either very brief, or longer but filled with stuttering sounds, and the strained or discordant quality of the sound.

That discovery allowed me to be confident in identifying the first two-spotteds singing in DuPage County, Illinois, this year, on July 12. That is the earliest song date I have for that species, by 5 days.

I also heard the year’s first ground crickets in DuPage. I had been gone a week, and returned to hear striped (photo below) and Allard’s ground crickets on July 12, and Carolina ground crickets on the 13th (I had heard all three near Culver, Indiana, on July 8). Though not the earliest ever, all three species were singing near the earliest first song dates I have noted for them since my study began in 2006.

Mayslake Forest Preserve is one of the DuPage County sites where there are fall field crickets but no spring field crickets. So, when I heard a field cricket song there on July 14 I marked the beginning of that species’ singing season (female shown).

During First Folio Theater’s evening performance of Twelfth Night at Mayslake I heard a few protean shieldbacks singing, my first record of that katydid species on that preserve (female shown).

Finally, I heard my first sword-bearing coneheads of the year while driving to Culver on the evening of July 16.

There are plenty of other species yet to begin, but it feels like the singing insects season has begun in earnest.

Protean Shieldback

by Carl Strang

Yesterday as I rode my bike through Blackwell Forest Preserve I heard my first protean shieldback songs of the year. The scientific name of this katydid is as musical as its common name: Atlanticus testaceus.

Atlanticus female 2b

This is our only common native species of predaceous katydid. We also have a common non-native species, Roesel’s katydid, which I will feature soon. They are called predaceous katydids, but the main point is that they draw their nutrients from animal, rather than plant foods. They are scavengers as well as predators. Protean shieldbacks were very abundant two springs ago, during the periodical cicada emergence. In part this is because they fed well by scavenging dead cicadas, but they probably also benefited from their predators being sated on cicadas. Their carnivorous diet allows them to mature faster than their vegetarian relatives, and so they are the earliest katydids to sing each year (though the common meadow katydid is not far behind).

Protean shieldbacks don’t usually venture far from woody plants, and are fairly common in woodlands, woodland edges and brushy areas in DuPage County. I have found them in grassy fields with dense tall herbaceous plants, too. The males sing from late afternoon until well after dark. Their song is a soft rattling buzz, moderately high pitched, lasting 1-6 seconds. The sound quality is like a stage whisper, I would render it a rapid “thithithith…” about twice as fast as I can produce vocally. For a sound recording, go here  or here . Their season isn’t long; they will be done by mid-July.

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