Southern Lessons

by Carl Strang

This year’s chapter in the series of annual bioblitzes organized by the Indiana Academy of Sciences took place at Eagle Creek Park in northern Indianapolis on June 2-3. This is early enough in the season that there were few singing insects for me to find, but I was able to gain valuable experience with two southern species that occur or have occurred in the Chicago region.

The first of these is the spring trig.

Female spring trig at Eagle Creek.

This species of tiny cricket first was described in 2014. That is surprising, given its abundance in southern Indiana and its extensive range beyond the state. It proved to be common in a range of habitats at Eagle Creek Park, from woodland edges to grassy meadows.

Spring trigs appear plain-faced to the eye, but bright light and magnification reveal a pattern of fine dark lines.

I learned more about the spring trig’s habitat, and found that I can hear them easily while driving at speeds of 30mph or less. This allowed me to get clarity on the species in the Chicago region. Driving in the southernmost counties, I found widely scattered small colonies in Fulton and Jasper counties, at road edges where wider bands of herbaceous plants were backed by woodlands. In the future I expect to find them in southern Pulaski and Newton counties, too, but not north of there.

Eagle Creek Park also has a large population of northern wood crickets.

The northern wood cricket is a forest species that is smaller and blacker than the spring field cricket, which could be heard chirping in the park’s meadow areas.

The spring field cricket is a few millimeters longer, typically has bronzy wings, and has a proportionately broader head and thorax.

Recordings I made during the bioblitz, and at home with a captive male, have provided further clarity on northern wood cricket song characteristics. Their chirps may never have 4 pulses (commonly 2 or 3), and almost never rise above 5 kHz in pitch, where spring field crickets often have 4-pulse chirps, and seldom drop below 5 kHz. Habitat also helps separate the two. I dug deeper into the literature, and learned more about historical records of the species in two Chicago region counties. Those observations were made in 1902, and I went to the sites in the weeks after the bioblitz. Northern wood crickets no longer occur there. I believe the records are correct, but that the crickets have gone extinct in those places. Northern wood crickets are reported to be sensitive to forest fragmentation, perhaps especially so in the northern fringe of their range, and such fragmentation clearly took place where they once were found in Lake and Marshall counties. I will continue to check the region’s larger surviving forest blocks, but it seems likely that the species no longer occurs in northern Indiana.

Incidentally, the other expected early-season singing insect, the green-striped grasshopper, lives in Eagle Creek Park’s meadows and prairie areas.

Next year’s bioblitz is expected to take place in one of my counties, and I am looking forward to the experience.

 

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Down the Rabbit Hole in Indy

by Carl Strang

Most bioblitzes occur in the spring, ahead of the main singing insects season. When one was announced for mid-September in Indianapolis, I was quick to sign on. Bioblitzes are good opportunities to go beyond one’s familiar region and gain wider experience, but this one brought enough strange observations that it was somewhat disorienting. The dominant singers everywhere were Japanese burrowing crickets.

Japanese burrowing cricket

Japanese burrowing cricket

That Asian species has been spreading from Mobile, Alabama, where it was introduced to North America in the 1950’s. I expect it eventually to become common in the Chicago region.

Walking a streamside trail at dusk on the first evening, I heard a meadow katydid that did not quite match other species of my acquaintance.

The pale face and eyes reminded me of a recent find by Lisa Rainsong in Ohio.

The pale face and eyes reminded me of a recent find by Lisa Rainsong in Ohio.

Oblique ventral view of the male’s cerci.

Oblique ventral view of the male’s cerci.

Another angle on the cerci. The tips are round rather than blade-like, and the teeth are not unusually long.

Another angle on the cerci. The tips are round rather than blade-like, and the teeth are not unusually long.

The song also was distinct, with very brief buzzes rather than ticks between the major buzzes, and significant pauses between. All of this points to the agile meadow katydid (suggested as a possibility by Wil Hershberger), a southern species not previously documented any closer than Tennessee or Virginia, according to the map in the Singing Insects of North America website.

If that weren’t enough, there were the strange finds in a little wetland area surrounded by a mowed Frisbee golf course at one of the parks.

Two little patches of cattails, grasses and sedges, with wet soil between.

Two little patches of cattails, grasses and sedges, with wet soil between.

There I found a female green-striped grasshopper.

This is a spring species in the Chicago area, totally unexpected in mid-September.

This is a spring species in the Chicago area, totally unexpected in mid-September.

They are known to have two annual generations in the South, and apparently such is the case as far north as Indy.

The bigger surprise was that these little habitat islands held a dense population of dusky-faced meadow katydids.

I caught and photographed males and females to be sure. There was only a little of the red facial spotting and network, but the cerci and ovipositors were definitive.

I caught and photographed males and females to be sure. There was only a little of the red facial spotting and network, but the cerci and ovipositors were definitive.

Also, the song was exactly the same as in the Chicago region. Perhaps this species is more abundant downstate, where invasive wetland plants reportedly are not as thoroughly established as they are farther north.

All in all, it was a horizon-expanding weekend.

 

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.

 

Singing Insect Season Opens

by Carl Strang

There have been several early season warm periods this year, allowing the greening of food plants and the higher temperatures that support invertebrate growth. I have anticipated that this might be a relatively early year for the first sound displays by green-striped grasshoppers, and that expectation was realized on Monday when I heard the fluttering buzz of a flying male, and got a glimpse of him as he landed.

Male green-striped grasshopper photographed in an earlier year.

Male green-striped grasshopper photographed in an earlier year.

This was the second-earliest date in 11 years of observations, and was 15 days ahead of the median first display date. As you walk though areas with unmowed grassy growth, listen for a soft buzzing sound. This is the controlled rattling of wings by a grasshopper at the end of a display flight. With some luck you may catch the insect’s motion and get a look at one.

Early Season Survey: North

by Carl Strang

On Tuesday of last week I drove north to seek early season singing insects in 5 Wisconsin and northern Illinois counties. I was prepared to camp overnight, but with rain in the forecast for the next day I was happy to complete the run in one day.

My first stop was Middlefork Savanna in Lake County, Illinois.

My first stop was Middlefork Savanna in Lake County, Illinois.

Spring field crickets were singing, but vegetation still was wet from an overnight rain, and I was lucky to spot this greenstriped grasshopper to give me that county record.

Spring field crickets were singing, but vegetation still was wet from an overnight rain, and I was lucky to spot this greenstriped grasshopper to give me that county record.

From that point it was rapid-fire site hopping, and I didn’t take many photos.

An exception was this Roesel’s katydid nymph at Wadewitz Nature Camp, a Racine County (Wisconsin) Park.

An exception was this Roesel’s katydid nymph at Wadewitz Nature Camp, a Racine County (Wisconsin) Park.

Wadewitz has extensive grassy meadows, and the biggest surprise of the day was not finding displaying greenstriped grasshoppers in the warm sunny mid-day. Ultimately I was able to find both spring field crickets and greenstripeds in all 5 counties, but several stops were required in some cases.

Singing Insect Season Opens

by Carl Strang

Last Wednesday the long silent drought of insect song was broken as I heard the first displaying green-striped grasshopper of the year, at Churchill Woods Forest Preserve. Then, on Friday, I found many of them buzzing in the south stream corridor prairie at Mayslake Forest Preserve.

This male rested after a relatively long flight.

This male rested after a relatively long flight.

If you want to listen for the crackling-wing songs of these grasshoppers, I posted a recording HERE not too long ago. They show up in all kinds of grassy areas.

I continue to be puzzled by green-striped grasshoppers. Sometimes their buzzing display flights are long, and fairly easy to see. Most of the time, though, I hear briefer buzzes and do not see any movement. Either I am not correctly locating the displaying insect, or they can buzz within the vegetation without flying. I don’t think these simply are very short display flights, because the grasses in that prairie are matted nearly to the ground. On the other hand, the males are well camouflaged, their wings are not colored like those of many of their relatives. On the longer flights they are most visible at the beginning and end, practically disappearing in the fast major portion.

Sound Ideas: Green-striped Grasshopper

by Carl Strang

We are within two months of the start of the singing insect season in the Chicago region. Opening day is marked by the first displays of the green-striped grasshopper.

Male green-striped grasshopper

Male green-striped grasshopper (females usually are green)

These grasshoppers get their early start because they overwinter as nymphs, and so can mature quickly in the spring. Their displays, which qualify them as singing insects, consist of short flights in which they rattle their wings, producing a buzzing sound:

That this is a display is demonstrated by the fact that when they are flying to avoid the pursuit of a possible predator, they do not make that sound.

Mayslake Catch-up

by Carl Strang

Now that we are getting autumnal weather, it’s a good moment to look back at the summer just past, and at the current hints of what is coming. Here are photos from the past month at Mayslake Forest Preserve.

This dorsal view of a black-legged meadow katydid doesn’t show off his colors, but as he pauses between songs we can see the sound-production structures in the bases of his wings.

This dorsal view of a black-legged meadow katydid doesn’t show off his colors, but as he pauses between songs we can see the sound-production structures in the bases of his wings.

Usually I’m good at spotting bee mimics, but this large syrphid fly had me calling it a common eastern bumblebee for several seconds before I realized my error.

Usually I’m good at spotting bee mimics, but this large syrphid fly had me calling it a common eastern bumblebee for several seconds before I realized my error.

According to BugGuide, “larvae are deposit filter-feeders in water-filled tree holes,” which explains why Mallota bautias don’t turn up very often.

When I spotted the scissor-grinder cicada on the horizontal branch I took advantage of the opportunity for an unobstructed telephoto. Only when I was cropping the picture in the computer did I notice the second individual on the vertical branch.

When I spotted the scissor-grinder cicada on the horizontal branch I took advantage of the opportunity for an unobstructed telephoto. Only when I was cropping the picture in the computer did I notice the second individual on the vertical branch.

So much for summer. Now for hints of the season to come.

This brown, probably male, nymph is a greenstriped grasshopper, the species that will kick off the singing insect season next spring. They get started early because they overwinter in this form rather than in eggs as do most of the species singing now.

This brown, probably male, nymph is a greenstriped grasshopper, the species that will kick off the singing insect season next spring. They get started early because they overwinter in this form rather than in eggs as do most of the species singing now.

This Henry’s marsh moth caterpillar was clambering over the tangled stems of a reed canary grass patch, probably seeking a pupation spot for its winter hibernation.

This Henry’s marsh moth caterpillar was clambering over the tangled stems of a reed canary grass patch, probably seeking a pupation spot for its winter hibernation.

These mink scats, freshly deposited on a path near the stream, are the first sign of that species I have seen in a while. Perhaps this mink will center its winter activities around Mayslake’s wetlands.

These mink scats, freshly deposited on a path near the stream, are the first sign of that species I have seen in a while. Perhaps this mink will center its winter activities around Mayslake’s wetlands.

Reptiles and amphibians are moving toward their hibernacula. Recently I spotted a garter snake that looked different from the usual Chicago version of the eastern garter snake.

It was paler around the head and neck.

It was paler around the head and neck.

The side stripe is on scale rows 3 and 4, and other details support the identification of plains garter snake, a new species for the Mayslake list.

The side stripe is on scale rows 3 and 4, and other details support the identification of plains garter snake, a new species for the Mayslake list.

Singing Insects in Transition

by Carl Strang

We are at a point in the season where the spring-singing insects are finishing, and the early summer brings new voices to the chorus. Green-striped grasshoppers seemed to tail off rapidly in their crepitating flights this year. I have heard very few in recent weeks.

The male green-striped grasshopper usually is brown. He’s the one who does the displaying.

The male green-striped grasshopper usually is brown. He’s the one who does the displaying.

The object of his displays usually is green, and a bit bigger than him.

The object of his displays usually is green, and a bit bigger than him.

Roesel’s katydids rapidly are increasing the number of buzzes they are contributing to the meadows and prairies.

Note the blur in the wings as this short-winged Roesel’s katydid sings. Some individuals have much longer wings.

Note the blur in the wings as this short-winged Roesel’s katydid sings. Some individuals have much longer wings.

Over the weekend I heard first songs from three additional species: Linne’s and dog day cicadas, and the gladiator meadow katydid.

This was one of several gladiators singing beside the Regional Trail in south Blackwell Forest Preserve Saturday evening.

This was one of several gladiators singing beside the Regional Trail in south Blackwell Forest Preserve Saturday evening.

Those Tibicen cicadas, especially, characterize the sound of summer for me.

Singing Insect Season Opens

by Carl Strang

The first displays by greenstriped grasshoppers always mark the start of our singing insect season, and this happened yesterday as I heard two displaying males in the prairie at Mayslake Forest Preserve. The rattling crepitations of the display flights at last ended the long winter’s drought. The May 12 date is relatively late, ranking 7th out of the 8 years in which I have kept records. The next anticipated singer is the spring field cricket, which I hope to start hearing in another 2 weeks or so.

The greenstriped grasshopper gets the jump on other singing species because it overwinters as a nymph rather than an egg.

The greenstriped grasshopper gets the jump on other singing species because it overwinters as a nymph rather than an egg.

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