Roesel’s Katydid Quest

June 30, 2009 at 8:43 pm (singing insects)
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by Carl Strang

Earlier I featured northeast Illinois’ common native predaceous katydid, the protean shieldback . We have another predaceous katydid, an import from Europe, Roesel’s katydid. Here is a female. Note the general brown color, and the yellow-edged half-moon of black behind the head.

Roesel's katydid female 2b

This is a species of open prairies, meadows and roadsides, preferring a mix of tall grasses and forbs. Here is a male in singing posture.

Roesel's katydid b

There are two things to note in comparing the two photos. First, the female is recognized by the curved, bladelike ovipositor protruding from the back of her abdomen. A structure of this sort is present in all female crickets and katydids. Second, note the long wings of the male and the short wings of the female. This is not a gender difference, as either gender can have either wing length. The male’s singing structures are in the basal part of the wings, and are complete in short-winged individuals.

Range maps for Roesel’s typically show it in a fairly large area of the northeastern U.S. plus a separate, smaller area in northern Illinois. I expected to find it in DuPage County. It is indeed abundant here, and I have found it in Kane and Kendall Counties as well. Imagine my surprise two years ago when, riding my bicycle around Culver, in north central Indiana, I started hearing the distinctive flat buzzing songs of Roesel’s katydids. I interrupted my workout to find one, and confirmed its identity visually. I intended to begin exploring the extent of their range extension last year, but a bike fall in mid-June gave me a broken collarbone and rib, forcing a postponement.

Last week I took a couple vacation days and searched for Roesel’s in two additional Indiana areas. First I drove to North Manchester in Wabash County, home of Manchester College.

Manchester College 3b

I covered 25 miles of country roads on my bike, and found scattered Roesel’s both west and east of North Manchester. I collected a voucher specimen.

Roesel's voucher b

I’m not fond of killing insects, but in this case felt the need for a voucher to support my claim. For what it’s worth, the greatest concentration of them was at the intersection of county roads 1400N and 300W.

Roesel coll site 2b

I found a larger than usual area of unmowed mixed grasses and forbs there.

Roesel coll site 3b

That was the source of the voucher specimen. The next day I drove down to Logansport for another prospecting bike ride. In a 22-mile tour of Cass County roads from the Wabash River north, again I encountered Roesel’s katydids regularly along the way. As on the previous day there were plenty of spring field crickets, too, plus a number of common meadow katydids, the first I’ve heard this year.

Roesel’s song is a mechanical sounding buzz, lengthy but with occasional interruptions. Nothing else produces a sound like it so early in the season. The males usually begin singing around mid-morning (though on a hot day I have heard them as early as 7:15 a.m.), and continue through the heat of the afternoon. In northeast Illinois the earliest appearance I have noted was June 10 (in 2007), latest June 22 (last year). They continue into the second half of July (the latest I have heard one was July 28 in 2006). For recordings of the song, go here  or here . You also can see the conventional range map, which clearly needs updating.

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Prairie Flowers and Others

June 29, 2009 at 9:38 pm (botany)
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by Carl Strang

We have entered a part of the season when most newly appearing native wildflowers are those of prairies and other open areas. Woodlands are so shaded by now that most of their flowers have finished blooming. One common exception is the white avens.

White avens b

This member of the rose family is one of our most common woodland plants. Its seeds have little hooks for catching the fur (or clothing) of passing mammals, which then convey them. Earlier in the season  I mentioned another avens, the yellow avens, which since has proven to be ubiquitous at Mayslake to the point where I don’t remember seeing it nearly as abundant anywhere else. A third avens species is the rough avens.

Rough avens b

This one is much less common at Mayslake, growing mainly in somewhat open places close to the stream or other bodies of water. Water also is the home for the beautiful flowers of the water knotweed.

Water knotweed 2b

This one is abundant in parts of the marsh between the stream and the chapel. The rest of the flowers featured today are prairie forbs. A forb is an herbaceous species that is not a grass, sedge or similar plant. The criterion is not, however, wind pollination vs. animal pollination. The waxy meadow rue is a wind-pollinated forb.

Waxy meadow rue 1b

Dogbane is the native plant which produces the best fibers for rope making.

Dogbane 2b

Other prairie plants have names suggesting uses we may have found for them: food (wild onion),

Wild onion b

dye (white wild indigo),

White wild indigo 2b

and medicine (wild quinine,

Wild quinine b

and purple coneflower).

Purple coneflower b

The last has become a popular herbal remedy under its genus name, Echinacea. Medical researchers are skeptical of its efficacy, but I find that laboratory studies do not carefully replicate traditional preparation methods and so themselves have to be regarded as inconclusive.

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Mayslake Lepidoptera Update

June 28, 2009 at 9:29 pm (insects (other))
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by Carl Strang

Recently I provided an update on damselflies and dragonflies that have become active at Mayslake Forest Preserve. New butterflies and moths also have been appearing. The large group of butterflies known as skippers can be tricky, but I believe I have these right: Hobomok skipper,

Hobomok skipper b

and tawny-edged skipper.

Tawny-edged skipper 2b

Both are, according to my references, common. I have found Hobomoks in other preserves early in the season. Even more common and distinctive are two more species, the least skipper

Least skipper 2b

and silver-spotted skipper, the latter never far from black locust trees.

Silver-spotted skipper b

The most recent butterfly to show itself has been the spring azure.

Spring azure 2b

Moths also are in evidence. This one, Zanclognatha cruralis, belongs to a curious group whose larvae eat dead leaves.

Zanclognatha cruralis b

The following moth I photographed on the slope between May’s Lake and the friary, not far from a large white pine.

Semiothisa bisignata cropped b

This one proved to be a tough ID. There is a large group of moth species which look very much like this one. Furthermore, many of these species show considerable variation among individuals. The yellow head and anterior thorax are unusual among them, I gather, and help to narrow down the possibilities. My tentative identification is Semiothisa bisignata, the caterpillars of which eat pine needles. In the future I may need to collect one or more of them. With some insects, photographs simply aren’t enough.

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Mayslake Bird Notes

June 24, 2009 at 6:09 am (birds)
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by Carl Strang

We are well into the nesting season for nearly all species of birds in northeastern Illinois. The white-breasted nuthatches in the savanna have fledged their young.

Nuthatch fledge 1b

There were four fledglings. They moved about 50 yards from the nest and stayed in a small area for a few days, then drifted west out of the savanna. Nearby, blue-gray gnatcatchers scrambled to keep up with the demands of their more scattered youngsters.

Gnatcatcher b

The red-bellied woodpeckers (one pair on the preserve) have their young near to fledging. Here an older nestling peers out,

Rb woodpecker nestling 1b

and soon is gratified by Mom’s arrival.

RB woodpecker mom at nest b

Meanwhile, a male bluebird has been favoring a song perch atop the chapel.

Bluebird cross b

(That’s the tip of a lightning rod behind his head). Several bluebird houses are near, but some are occupied by tree swallows. I have seen fledgling swallows recently, which means there are vacancies. A final bird topic pertains to chimney swifts.

Chimney swift 1b

A review of the literature on the species indicated that a given chimney will have only one nest in it. The Mayslake mansion provides for a possible inquiry on this subject. Some active chimneys have been capped, and so are unavailable.

Chimney 2b

Other chimneys are not capped. I once saw a swift drop into one of the chimneys in this pair.

Chimney 3b

Here is yet another tall chimney.

Chimney 4b

Especially intriguing are the fake chimneys.

Chimney 1b

This set of 8 stacks is entirely decorative, but I have twice seen swifts drop into one of the holes in the southwest quarter. This is where the potential for inquiry comes in. Given that a single hole will have only one swift nest, do the extra holes in clustered chimneys, fake or real, provide additional nesting habitat or will one pair claim the entire cluster? I have not seen swifts entering chimneys often at Mayslake, but I will continue to collect observations in hopes of addressing this question.

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Mayslake Odonata Update

June 23, 2009 at 6:31 am (dragonflies and damselflies)
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by Carl Strang

The weather has been rainy, gloomy and cool on many recent days, but when the sun appeared so did the insects. At Mayslake Forest Preserve I have been able to add new species and observations that provide a foundation for future study. Eastern forktail damselflies already have been busy laying eggs in May’s Lake.

Eastern forktails laying eggs b

Meanwhile, other damselflies are emerging. The next two photos are, I believe, of common spreadwings, a male

Common spreadwing b

and a female.

Common spreadwing female 3b

Having newly emerged, they are holding their wings together more than usual. Another spreadwing species is the slender spreadwing.

Slender spreadwing 1b

Note the contrasting pale veins of the wingtips. Another, blurry photo established that the abdomen has the characteristic length, twice that of the wings. I have seen orange bluets at both of the preserve’s lakes.

Orange bluet b

Familiar bluets also have begun to appear.

Familiar bluet b

The year’s first blue-fronted dancer was a female.

Blue-fronted dancer female b

Its abdomen is dark, including the sides of the tip, and has only a very narrow pale line down the top. Shifting now to dragonflies, I’ll start with a 12-spotted skimmer that began patrolling the stream corridor marsh in June. I expect the species to be common there. This one I photographed elsewhere in 2004.

12-spotted skimmer b

Blue dashers have been active out in the fields, and soon will be appearing at lakes and marshes.

Blue dasher female 1b

A jade clubtail has staked out a piece of the May’s Lake shore.

Jade clubtail b

Cruising farther out are the prince baskettails. Here is a UFO-ish shot of one.

Prince baskettail UFO b

And here is a common baskettail  showing the basal wingspots that are visible on some, but not all individuals.

Common baskettail spot b

A final, cautionary photo:

Eastern forktail new female b

This is not an orange bluet, but a newly emerged female eastern forktail. Note the absence of the orange at the abdomen tip plus the expanded orange area at the base of the abdomen.

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More Beautiful Weeds

June 22, 2009 at 6:12 am (botany)
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by Carl Strang

Time for another installment in the Mayslake phenology series, this one adding the latest flowering plants that are non-native, undesirable, or with a weedy life history strategy . Let’s begin with musk thistle.

Musk thistle b

This European plant reaches impressive size, so that the large flower heads are dwarfed by the enormous spiny stem: a definite undesirable. A smaller, even more problematic thistle (same family, different genus) is the Canada thistle (native to Europe, not Canada).

Canada thistle b

Canada thistles take over patches of open habitat and can be difficult to eradicate. Other European species that are less problematic are the field hawkweed

Hawkweed b

and common St. John’s wort.

Common St John's wort b

Native plants with weedy ecological traits include hedge bindweed,

Hedge bindweed b

annual fleabane,

Annual fleabane 2b

daisy fleabane,

Daisy fleabane b

and black-eyed Susan.

Black-eyed Susan b

Some non-native shrubs on the preserve, no doubt planted for landscape purposes but now growing in wilder spots, are downy mock orange,

Mock orange 1b

and two (count ‘em) 2 (yes) too! privets. These are the common privet,

Bombus bimaculatus privet 2b

which proved  to be the identity of my mystery seedling in Culver, Indiana, and the similar border privet.

Border privet b

The first two shrubs are European, the last Asian.

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Cowbird Fledglings

June 21, 2009 at 6:03 am (birds)
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by Carl Strang

Over the past 2-3 weeks I have been noticing cowbird fledglings at Mayslake Forest Preserve. These are the offspring of obligate nest parasites: brown-headed cowbirds cannot nest themselves, but rather lay their eggs in the nests of other birds. Foster parents that fail to recognize the foreign egg will raise the baby cowbird, often at the expense of their own young. The cowbird develops rapidly, and begs vigorously, gaining an advantage. Here is a fledgling cowbird raised by Mayslake’s eastern phoebes earlier this year.

Cowbird fledgling 2b

I saw no phoebe fledglings. The cowbird’s begging call is distinctive. It sounds like a chorus of baby birds, and probably qualifies as a supernormal releaser. That term refers to an exaggerated stimulus that produces a particular instinctive response by an animal. In this case, the call draws disproportionate attention, in the form of food, from the foster parents. If you hear a chorus of baby birds that all start at once and all pause for breath at once, you probably are hearing a single cowbird youngster.

I heard this call coming from the cottonwood tree bearing the south savanna Baltimore oriole nest . As I like to do, I found the cowbird and waited to see what would come to feed it. The foster parents were the orioles. Here the female feeds the cowbird.

Baltimore oriole feeds cowbird b

I watched for a few minutes, during which the female fed the cowbird three times, the male oriole fed the cowbird once, and he fed the baby orioles (still in the nest) once. A period of rain and work duties kept me from checking for a couple days, by which time there was no sign of any of these birds near the nest.

Over the years I have seen cowbird fledglings being fed by yellow warblers, song sparrows, scarlet tanagers, blue-gray gnatcatchers and cardinals. Cardinals are common at Willowbrook Forest Preserve, but for several years the only time I saw cardinal fledglings was late in the season, after the cowbirds were done. All early products of cardinal nests were cowbirds. This kind of selective pressure is what has led many birds to evolve the capacity to recognize and reject cowbird eggs. Obviously such an ability remains to emerge in many others. Incidentally, once the cowbird becomes independent, it instinctively seeks out other young cowbirds and behaves as a cowbird from then on.

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Garlic Mustard Study: Final Spring Results

June 20, 2009 at 5:02 am (botany, restoration)
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by Carl Strang

One of my studies this spring has been an experimental comparison of removal techniques for garlic mustard, an invasive biennial that poses problems in our woodlands because it inhibits the growth of all other plants (including trees).

GM bolting b

A month ago I removed all the second-year plants from my study plots. As I reported then, it was clear that pulling the plants in March was more effective than was cutting them off at ground level, though both treatments killed most of the plants. In the following photo you can see an example of new side shoots springing up from where the main stem had been clipped.

GM clipped recovering b

In that May treatment I also clipped the control plants at ground level. After waiting four weeks I recently returned to see whether any second-year plants had recovered to send up new stalks. I also wanted to check progress of seedlings, which had been suppressed by the control plants but had been growing vigorously in treatment areas.

The results again were impressive. All but 6 of the 1482 control plants (99.6%) were killed by the May clipping treatment, in contrast to clipping in March. None of the few survivors of the pull treatment that I cut in May survived. More (17) second-year plants survived their second clipping.

GM 15JE 1b

At the moment it appears that early pulling and late clipping both are effective techniques, but I have more tests to do next year. The jury still is out on the question of whether (or under what conditions) pulling may increase germination from the seed bank in the soil.

After a month the seedlings in the control squares still were far from making up the ground they lost in comparison to seedlings in treatment squares.

GM 15JE 3b

The next step in this study will be a return to count the seedlings in the fall. I am interested in how much they thin themselves through competition with one another.

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Protean Shieldback

June 19, 2009 at 6:18 am (singing insects)
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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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Fruiting Phenology

June 18, 2009 at 5:49 am (botany, ecology)
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by Carl Strang

Through the spring I have been introducing wildflowers as they have bloomed at Mayslake Forest Preserve. I record first flowering dates so as to make future comparisons between years. Flower timing is tied to climate. Plants, especially early in the season, are influenced strongly by soil temperature. Phenology, the study of when events occur, is by no means limited to flowers, or even to plants. I record arrival dates for birds, and also fruiting dates of plants whose fruits are consumed by vertebrates. This year the first of these at Mayslake has been a non-native species, the Tartarian honeysuckle.

Tartarian honeysuckle fruit b

The berries are consumed by birds, which disperse the seeds widely, enabling it to become a problem plant in restoration projects. I’ll share other fruits in future installments.

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