Silvery Checkerspot

by Carl Strang

Last week was the final session of the Roger Raccoon Club for the year. We always camp at Waterfall Glen.

Getting the tents up is the first challenge.

For lunch, the kids roast hot dogs.

A butterfly showed up at lunch time, landing on the kids to their delight, and then shifting to a water container.

At first glance it resembled the pearl crescent, a familiar species, but it was bigger and had a broad black edge to its wings.

Fortunately it also posed with wings closed.

The undersides of the wings also were subtly unlike those of pearl crescents.

We saw a number of these butterflies around the campground, which is in an area of open woodland culled of buckthorn and honeysuckle brush a few years ago. The photos allowed me to identify them as silvery checkerspots. Their larval diet includes a variety of composite genera well represented in the area.

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Bioblitz Incidentals

by Carl Strang

While my main focus at the Kankakee Sands bioblitz was on observing singing insects, I also was noting other species along the way, and was interested in others’ observations of singing insects. Someone in the Purdue entomology group collected a female bush katydid, for example.

The ovipositor marks it as female, the wing proportions and head shape place it among the bush katydids (genus Scudderia).

Female bush katydids are tricky, but I’m pretty confident that this is a Texas bush katydid. The sharp bend in the ovipositor, especially the inward or upper edge, narrows it down to a very few species. A broad-winged bush katydid would have broader wings, and a fork-tailed bush katydid would have a reddish-brown rather than green ovipositor. The colors and shapes of other structures around the ovipositor, and the shape of the ovipositor itself, match those of the Texas bush katydid, which is a common species of prairies like the one where this insect was collected. I didn’t hear any singing, but in DuPage County these tend to start up later in the season.

I saw a number of little yellow butterflies that had the markings of sulphurs but were unfamiliar to me.

The little sulphur is a species associated with sandy soils, and so unlikely to turn up in my familiar DuPage County haunts.

A milkweed leaf beetle turned up in a sweep sample in one of the prairie areas.

Like so many other milkweed feeders, this species has colors of black and orange.

Alyssa noted that I had picked up a hitchhiker at one point.

This proved to be Henry’s marsh moth, a noctuid of wetlands with a broad larval diet.

One of our nets caught an impressive jumping spider.

It was a big one, marked by a white stripe across the abdomen.

Finally, I photographed a grasshopper nymph that I thought might belong to a stridulating species, but I think it is in the wrong group.

I heard a grasshopper stridulating, but never saw it, and was only guessing here.

Grasshoppers are a group I usually will need to collect for identification.

Robust Conehead

by Carl Strang

One of the target species this year in my singing insects study was the robust conehead, a large katydid. It had proven to be absent from DuPage County, though the entire region is included in range maps for the species, and Richard Alexander had reported that he collected one in southern DuPage decades ago. Last year I concluded from my literature review that it primarily is a species of sandy soil areas, at least in the northeast Illinois-northwest Indiana region. As I drove the roads after dark in the Kankakee Sands bioblitz, I quickly found robust coneheads to be common.

Male robust conehead, wings elevated into singing position.

Their song is indeed as loud as the literature suggests. Like those of some other conehead species, it is a high-pitched continuous buzz, but it is so loud that it carries a long distance, and up close its volume is amazing. If a clincher is needed, the color of the cone provides it.

The underside of the cone at the tip of the head has no black area, though reportedly sometimes there is a narrow dark line at the end.

Robust coneheads generally occurred in tall dense herbaceous vegetation in open areas. On occasion this included narrow roadside strips backed by woodlands, though such sites were never far from more extensive openings.

Straight-lanced Meadow Katydid

by Carl Strang

The Kankakee Sands bioblitz gave me the opportunity to learn more about the straight-lanced meadow katydid. My only certain identification in northeast Illinois was a male in Kane County last year. I had photographed some females with long ovipositors, but most of these seemed better fits as short-winged meadow katydids. An open area at the Conrad Savanna State Nature Preserve proved to have an abundance of straight-lanced, and they were the only members of their genus (Conocephalus) in that location.

This was a dry sandy-soil spot with grasses, whorled milkweed, hoary vervain, and a Lespedeza species as the major plants.

Mature females left no doubt.

The ovipositor length consistently exceeded the insects’ body length. Some of the literature I had seen had given femur length as the measure, but my experience in northeast Illinois had given me doubts.

Late-instar female nymphs likewise had exaggerated ovipositors.

In this one the ovipositor is much longer than the body.

Though I could hear the incessant buzzing, free of ticks typical of meadow katydid songs, that supposedly marks the straight-lanced song (using the SongFinder, of course), searching and sweep sampling produced just a single male, a nymph in the penultimate instar.

Already the cerci are showing extended flattened tips that will be even longer at maturity. They are long enough here to be diagnostic, I think.

I was paying attention to femur color patterns as well. Note the diffuse blackish stripe on the male nymph. I think this will prove to be diagnostic, when present. It is lacking in the mature female in the first photo, however. From this experience I am inclined to regard body length rather than femur length as the measure the ovipositor needs to exceed on a mature female meadow katydid to be considered a straight-lanced. Going back through my photo records, I found only one that met this criterion.

This one I caught in the dolomite prairie at Waterfall Glen Forest Preserve in 2010. Note the blackish stripe on the femur.

This was one of the two highlights of my singing insect survey at the bioblitz. I’ll share the other in my next post.

Kankakee Sands Bioblitz

by Carl Strang

For 24 hours on Friday and Saturday, over 100 field biologists convened at the Kankakee Sands area in Newton County, Indiana, for a bioblitz. The area includes Nature Conservancy prairie and savanna restoration sites and Indiana state nature preserves. The bioblitz, a concentrated effort to identify as many species of organisms as possible, was sponsored by the Nature Conservancy, Purdue University, The Indiana Academy of Science, and a consortium of Indiana colleges.

Check-in on Friday afternoon.

Though the bioblitz focuses on the central 24 hours, some advance work had been done.

For instance, a team of Purdue entomologists had begun collecting beetles the previous day.

My focus was singing insects. One of the Purdue students volunteered to assist me the first afternoon.

Alyssa Collins, a junior majoring in entomology, sports an entomological hitchhiker/hat.

Alyssa’s young ears were a huge help with some of the meadow katydids, which I cannot hear without an electronic aid.

For instance, she found this long-spurred meadow katydid, which proved to be a common species in the savannas.

I was prepared to collect extensively if necessary, but fortunately for my preferences we only needed to collect as we saw fit. I collected only 3 insects altogether. The long-spurred wasn’t one of them.

The song and habitat were sufficient for identification, but it doesn’t hurt to take advantage of photo opportunities. Here the male’s cerci show why this is named the long-spurred meadow katydid.

The timing was a little early for many of the singing insects. Meadow-dwelling tree crickets still were nymphs.

This one still is an instar or two short of maturity.

They generally were consistent with the black-horned/Forbes’s tree cricket species pair, but I will need to return in some future season to explore further.

Antennal spots which, if they hold to this arrangement after the final molt, will confirm my tentative ID.

We were able to spend some time in savanna and prairie areas.

Conrad Savanna, an Indiana state nature preserve.

Area L, one of the Nature Conservancy’s Kankakee Sands Efroymson Family Prairie Restorations.

In the next few posts I’ll share more from the bioblitz.

Gentle Herbivores…Not!

by Carl Strang

Crickets and katydids are largely vegetarians, but they are not above adding some meat to the diet. I saw an example of this while sweeping for meadow katydid nymphs at Mayslake Forest Preserve early last week.

This female nymph caught a small beetle that the net also had picked up, and systematically munched it down.

Protein, good for a growing katydid. Incidentally, I have learned from bird banders that they dare not leave birds in a mist net for long or the deer will eat them. So much for the Bambi image!

Going, Going, Gone

by Carl Strang

The drought we have been experiencing this summer in Illinois has taken its toll on the marshes at Mayslake Forest Preserve. On Monday of last week I took a panorama series of the stream corridor marsh to show how small the pool had become.

The west end

The center

The east end

At that point the pool was perhaps 30 feet wide and 50 feet long, but only inches deep. By Friday it was nearly gone.

At this point a single photo was sufficient to show perhaps 50 square feet of a pool only an inch or two deep.

Monday of this week, but a puddle remained.

Perhaps 5 square feet by less than an inch of depth.

On Tuesday it was gone.

Damp soil only marked the center of the marsh.

The basin was punctuated by the whitened shells of crayfish.

When will this marsh again see white river crayfish?

Some residents could emigrate easily, some could bury themselves and become dormant, but others could not, and when the water eventually returns the community will need to reconstruct itself.

Tree Cricket Nymphs

by Carl Strang

While sweeping for meadow katydid nymphs last week I also picked up a few immature tree crickets. I took the time to photograph some of them.

This example, just a few millimeters long, has no wing pads yet.

After consulting Nancy Collins’ excellent tree cricket site, I think this one is in its third instar, 3 molts short of adulthood. Other information on her site suggests, from the pattern of fine white dashes on the abdomen and lack of a striping pattern, that this might be a black-horned tree cricket, which is common at Mayslake Forest Preserve. It took some maneuvering to get a reasonably clear photo of the spots on the first two antenna segments.

Eventually, a Kilroy-was-here shot achieved the goal.

These spots are valuable in identifying adult tree crickets, but I don’t know whether they are useful in nymphs. This pattern certainly fits the black-horned/Forbes’s tree cricket species pair (cf. diagram at the Singing Insects of North America website).

Meadow Katydid Nymphs

by Carl Strang

One project in my study of singing insects is to learn to identify nymphs, the immature stages, of katydids. This could extend the survey season, as I could begin a month or two earlier than at present. At some point, rearing and taking quantitative measurements will be necessary (unless there is some reference I have not found), but for now I am taking a lot of photos and looking for possible characteristics to watch. I am beginning at Mayslake Forest Preserve, which has relatively few species. Recently the first slender meadow katydids matured and began to sing.

Mature male slender meadow katydid. Note the long wings, green cerci at the abdomen tip, and the green femurs with lines of tiny, separated black dots.

Some of the nymphs I was catching in the sweep net looked like they, too, might be males of this species.

This nymph likewise has green cerci, though not yet in adult form, and green femurs with tiny, separated black dots.

Some of the female nymphs show the same color pattern, though they have undeveloped ovipositors rather than undeveloped cerci.

Again, a bright green general color with tiny black dots on the femurs.

In contrast, many of the nymphs show color patterns that I suspect tie them to adult short-winged meadow katydids, the other common member of genus Conocephalus at Mayslake.

Note the browner ground color, the many brown dots, the yellow-brown cerci, and especially the femur with its central clear zone bounded on each side by a brown band.

Females are similar.

Again the green is paler, and the femur shows the same striping.

Some nymphs are more ambiguous, but most seem to fall into one or the other color pattern, which is encouraging.

Two Helper Wasps

by Carl Strang

Recently two new wasps appeared at flowers in the south stream corridor prairie at Mayslake Forest Preserve. It happened that one of them was featured in a recent post on Eric Eaton’s blog.

Bicyrtes quadrimaculata, so far seen only on common mountain mint flowers at Mayslake.

This is a tunneling solitary species that feeds its young paralyzed true bugs. Eric focused on one such prey, the marmorated stink bug (Halyomorpha halys), which has become an invasive pest of fruit crops. Though the wasp is supposed to dig only in sand, there is none at Mayslake, but perhaps there are some suitable spots along the little stream. I do not know if Halyomorpha has shown up in Mayslake’s old orchard, but the preserve no doubt holds a diversity of native true bugs the wasp can exploit.

On Friday another new wasp showed up.

Cerceris fumipennis, visiting rattlesnake master flowers.

As I reviewed some Internet references I found a site connecting this wasp with a different pest species. Cerceris likewise is a solitary tunneling wasp, but it focuses on beetles as food for its young. As this wasp has a taste for buprestids, it may have value in monitoring for emerald ash borers.

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