Centennial Bioblitz

by Carl Strang

The Forest Preserve District of DuPage County’s Centennial Bioblitz started under rain and somewhat cool temperatures last Friday night. We sent off the first plant survey teams and frog monitors, and a small bird team went out, but the rain continued. As the darkness built, it became clear that light stations for insects would get limited results. I gathered the group who had come for one of the public programs, and Purdue University entomologist Jeff Holland explained that the dripping water would explode their hot bulbs. We set up my ultraviolet light, and Jeff led the team into the forest at St. James Farm.

Dr. Holland examines a beetle one of the participants found.

Dr. Holland examines a beetle one of the participants found.

The kids had a great time catching fireflies, and finding insects and other creatures active in the rain.

Classic kid nature fun was had by all.

Classic kid nature fun was had by all.

When we stopped by the light on the way back, we found a few beetles and small moths, but the sheet mainly held a host of mosquitoes.

Amid hundreds of floodwater and other common mosquitoes, there were a few huge ones.

Amid hundreds of floodwater and other common mosquitoes, there were a few huge ones.

Late into the night, and much of the next day, my focus was on support and organizational work, but I did make two brief field excursions and added a few species to the count on the four preserves of the bioblitz survey.

This green darner showed off its bullseye face paint.

This green darner showed off its bullseye face paint.

Halloween pennants have been common around the county in the past week.

Halloween pennants have been common around the county in the past week.

I recognized the chickweed geometer from my preserve monitoring work at Mayslake.

I recognized the chickweed geometer from my preserve monitoring work at Mayslake.

Roesel’s katydids had begun to sing in the previous week. This mature male has short to medium-length wings.

Roesel’s katydids had begun to sing in the previous week. This mature male has short to medium-length wings.

This coneheaded katydid nymph at the edge of the parking lot meadow was large enough, and its cone the proper shape, to be a sword-bearing rather than round-tipped conehead.

This coneheaded katydid nymph at the edge of the parking lot meadow was large enough, and its cone the proper shape, to be a sword-bearing rather than round-tipped conehead.

The botany teams no doubt caught this one, but I couldn’t resist photographing these starry Solomon’s plume fruits at Blackwell.

The botany teams no doubt caught this one, but I couldn’t resist photographing these starry Solomon’s plume fruits at Blackwell.

Our rough estimate at the end of the bioblitz was 900 species documented for the four preserves. I will report more detailed numbers when we have them.

 

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Sound Ideas: Coneheads

by Carl Strang

When I mention the coneheads to people unfamiliar with singing insects, the response almost always is a smile. I have to agree: one reason why the slightly musical conehead is my favorite singing insect (at the moment) is that name. Our coneheads are all katydids in genus Neoconocephalus. I have been fortunate to spend some time in the field with Gideon Ney, a Ph.D. student at the University of Missouri who is working out of a lab led by Johannes Schul that has done a lot of work with the evolution of that group. Thanks to Gideon I am aware of two species of coneheads that are not supposed to occur as far north as the Chicago region, but turn out to be at least locally common. Today I share recordings of the 6 documented species in the region. Warning: these are not delightfully musical or even (despite the name mentioned above) slightly so. We’ll ease into it with one that is somewhat pleasant to hear: the sword-bearing conehead. Its song:

That recording was made in a grassy upland meadow, typical habitat for the species, but close enough to the edge of the woods that a few common true katydids came through loud and clear. The conehead’s song is the continuous string of rasping ticks or brief buzzes. It has been compared to the sound of a sewing machine or a distant steam locomotive.

The sword-bearing conehead is named for the very long, straight ovipositor on the female.

The sword-bearing conehead is named for the very long, straight ovipositor on the female.

The next species also has a discontinuous song. The slightly musical conehead was given that name because W.T. Davis, who described it, thought it was not very loud (though he later changed his mind on that point).

The rasping sounds are easy for me to hear even with my older ears. This is a wetland species, and the males typically sing in unison.

The coneheads are named for the structure on the tip of the head, especially prominent in the slightly musical conehead.

The coneheads are named for the structure on the tip of the head, especially prominent in the slightly musical conehead.

Another species with an interrupted song is the Nebraska conehead.

The buzzes are not as rough as in the previous species, and will be heard in bushy undergrowth of woodlands, or sometimes bushes out in fields. In the southern part of the Chicago region, where the species is more common, the males sometimes sing in unison as well.

Male coneheads often sing head down. It has been speculated that the cone helps them penetrate the vegetation beneath when they are disturbed and drop to hide. Nebraska coneheads have medium sized, all black cone undersides.

Male coneheads often sing head down. It has been speculated that the cone helps them penetrate the vegetation beneath when they are disturbed and drop to hide. Nebraska coneheads have medium sized, all black cone undersides.

The remaining 3 species all have continuous buzzes. Most common region-wide is the round-tipped conehead, a katydid of meadows and roadsides.

Listen for a crackling sound in this continuous buzz.

Here the cone is short, round, and has a small black area near the tip.

Here the cone is short, round, and has a small black area near the tip.

Next is the marsh conehead, which so far has turned up only in the marshes of the Indiana Dunes parks.

The sound resembles that of the round-tipped, but comes from a wetland rather than dry upland habitat.

The cone of the marsh conehead may be all green as in this female, or show variable darkness of color.

The cone of the marsh conehead may be all green as in this female, or show variable darkness of color.

For the grand finale, here is the very loud song of the robust conehead:

This can be so loud as to be painful to the ears. It carries for long distances, as you may imagine, and is easy to hear from a car at any speed.

The robust conehead’s cone is unmarked and proportionately short. Any conehead species can come in green or brown.

The robust conehead’s cone is unmarked and proportionately short. Any conehead species can come in green or brown.

The robust conehead is most abundant in areas with dry sandy soils. Its habitat range is fairly broad, from open woodlands to prairies to corn fields.

There are at least two other species which are supposed to occur in the region, but which I have not found. Perhaps next winter I will have recordings of false robust coneheads and slender coneheads to share.

Mayslake Update

by Carl Strang

Today, some accumulated photos from, or at least connected to, Mayslake Forest Preserve.

The stream corridor marsh has become dry for the second year in a row, though this time it happened a couple months later.

The stream corridor marsh has become dry for the second year in a row, though this time it happened a couple months later.

Insects provided some photo ops.

This female sword-bearing conehead was the first of its kind I have seen at Mayslake in three years.

This female sword-bearing conehead was the first of its kind I have seen at Mayslake in three years.

Scissor-grinder cicadas occur in greater densities at Mayslake than in any other place I have found them to date.

Scissor-grinder cicadas occur in greater densities at Mayslake than in any other place I have found them to date.

This short-winged grasshopper appears to be a Melanoplus borealis, but I am not entirely sure.

This short-winged grasshopper appears to be a Melanoplus borealis, but I am not entirely sure.

The backdrop for the final photo is from Mayslake, but the pine tree cricket is the one Nancy Collins sent me from Wisconsin, still singing weeks later.

The cricket’s camouflage is superb.

The cricket’s camouflage is superb.

Snow fell for the first time yesterday: time for a new seasonal transition.

The Other Side of Range Extensions

by Carl Strang

The aspect of singing insect studies that has been of greatest general interest, and about which I have presented talks most frequently, is range extensions. Most of the several examples uncovered so far have been northward extensions of species ranges, and it is easy to jump to the conclusion that this is a product of global climate change.

The first species I found well north of where it previously had been known was the broad-winged tree cricket.

The first species I found well north of where it previously had been known was the broad-winged tree cricket.

If climate is the primary influence in these range extensions, we would expect the southern boundary of a species’ range to shift north as well. However, sticking with the example of the broad-winged tree cricket, its range has expanded south as well as north. I know that only because Tom Walker, the authority responsible for the Singing Insects of North America website, informed me that he has found them spreading down into parts of Florida where they had not been before.

Documenting an expansion northward is easier than demonstrating a disappearance in the south portion of a species’ range. It is easier to prove a positive than a negative. Also, when one has limited time and financial resources, it is not possible to travel south and conduct the necessary regional surveys. So, what to do?

The best idea I have had so far is to identify species whose southern range boundaries occur in my region, and make a point of documenting their presence and estimating their abundance from year to year. There are four best candidates.

The dog day cicada Tibicen canicularis has the northernmost southern range boundary. It is mapped down into the very northern edges of Indiana and Illinois, but I have found it a little farther south, at Braidwood Dunes in Will County, Illinois, and in southern Marshall County, Indiana. My notes suggest that its numbers may vary considerably from year to year in the latter location.

Dog day cicada

Dog day cicada

The broad-winged bush katydid Scudderia pistillata is mapped a little farther south, but I have found it infrequent in DuPage County, Illinois, and its season of activity seems to conclude sooner here than it does farther north. So far my surveys have turned it up in Lake County, Illinois, as well, but not farther south.

Broad-winged bush katydid

Broad-winged bush katydid

The striped ground cricket and sword-bearing conehead are abundant in the region. Their southern range boundaries are mapped about half a state south, but that is the same distance as a number of the northern range shifts I have observed. If entire ranges are shifting, one would expect them to be more scarce.

Sword-bearing conehead

Sword-bearing conehead

This is yet another topic of interest I am keeping in mind while surveying the region’s singing insect species.

Dispersal Ability

by Carl Strang

In order for us to understand insects well enough to know which ones need the most attention in conservation, there are some pieces of information we need: how abundant they are, how broad or narrow their habitat needs, their reproductive potential, and their dispersal ability. The first two items are readily obtained in the course of a regional survey such as I am conducting for singing insects in northeast Illinois and counties in neighboring states. Reproductive potential has been studied to some extent and can be found in the literature for some species. Dispersal ability is a critical point that is not well studied as far as I can tell, and so it is good to take advantage of observations that reveal which species spread easily, and which ones do not.

Over the past two weeks I spent much time in the St. Joseph Hospital in Mishawaka, Indiana, where the medical professionals saved my mother’s life.

The hospital was built 3-4 years ago, and is surrounded by extensive areas planted mainly in native prairie plants.

The hospital was built 3-4 years ago, and is surrounded by extensive areas planted mainly in native prairie plants.

Occasionally I took walks along the paths, or made observations while arriving or departing. The species present in the plantings can be regarded as ones with high dispersal ability. These included field crickets (I cannot be sure which, as this was the cusp between the spring and fall field cricket seasons), striped and Allard’s ground crickets, Carolina grasshoppers, Roesel’s katydids, and a sword-bearing conehead. All of these are regionally abundant, and fairly broad in their habitat (dry to mesic mixes of grasses and forbs). Three have good flying ability (in the case of Roesel’s, there are long-winged individuals as well as medium and short-winged ones). Field crickets and the ground crickets can take advantage of their regional abundance and tendency to hop and walk over land. One limitation here is that I was only able to make observations over a brief portion of the season.

If I had to point to the weediest singing insect in our region, I’d have to say it’s the striped ground cricket, which is the quickest to appear in a new site.

Learning to Identify Insect Songs

by Carl Strang

One of the obstacles to a singing insect monitoring program is the large number of various songs that need to be learned for identification. This is not really much different from learning bird songs for breeding bird monitoring, however (except that the total number of species is smaller here). Instead of being daunted by the entire process, it is possible to take the learning process in stages, beginning with the songs that are common and easy to recognize, the ones you have been hearing all along but simply didn’t have the species labels. Here is a list of a dozen suggested species to start with in the first stage: spring field cricket/fall field cricket (their songs are identical), Allard’s and striped ground crickets, snowy tree cricket, common true katydid, black-legged meadow katydid, greater angle-wing, round-tipped conehead, dog day cicada, scissor-grinder cicada, and Linne’s cicada (for more information on these species, try the tags at the head of this post).

Snowy tree cricket, one of the species on the starter list

This list and those that will follow are for northeastern Illinois and northwestern Indiana. There would be substitutions in other parts of the country (I encourage readers elsewhere to make comments here with their own suggestions). Go to reference recordings of these species’ songs, either on-line at the Singing Insects of North America website or through the CD that accompanies the Songs of Insects book. It is not too late this year to hear many of the species on this list on the warmer days, though some are finished or nearly so.

My recommended species list to focus on in the second stage of learning consists of 8 species and groups of species: greenstriped grasshopper, gladiator meadow katydid, Roesel’s katydid ( three species that sing relatively early in the season), and then later, Carolina ground cricket, Say’s trig, sword-bearing conehead, two-spotted/narrow-winged tree crickets (no need to worry yet about separating the two), and the meadow tree cricket group (3-4 species whose songs are essentially identical to the ear and will remain so).

Roesel’s katydid is a species from the second-stage list.

This list of common species either will take you to additional, though still readily available, habitats, or else require a little more of a practiced ear (which practice you got with the first species group). In particular, seek out and spend some time getting familiar with the songs of the Carolina ground cricket and Say’s trig. They need a little more effort to recognize in the field, but once you have them, they will be touchstones for many other species (much as robin songs are for learning bird vocalizations). If you are starting now, you might push the Carolina ground cricket to the first list, as it is one of the few species singing on the cooler days and evenings.

Once you have mastered the second list of species, you are ready for the more subtle distinctions needed to distinguish the songs in the third species list. This includes separating out the song of Linne’s cicada from similar songs by the lyric cicada, and in some areas, swamp and/or northern dusk-singing cicada.

Linne’s cicada

Also, by this point you are ready to distinguish the two-spotted tree cricket song from that of the narrow-winged tree cricket. Also, the broad-winged tree cricket should stand out now from other long-trilling species. In addition, you no doubt have noticed and begun to puzzle out other species that are more idiosyncratic in their distribution or smaller in numbers that you have encountered in your favorite places.

And that brings you to the fourth stage, learning the songs of whatever remaining species may live in the area you wish to monitor. For this you will need a regional guide. In the Chicago region, you can meet this need with the guide I am developing. It is available for free as a .pdf e-mail attachment. Simply request it at my work e-mail address: cstrang@dupageforest.com

As you are learning and listening, pay attention to which songs you can hear clearly, and at what distances, and which are marginal. This will inform the limitations you will need to address or acknowledge in your monitoring.

Chain O’Lakes

by Carl Strang

Last week I spent a day and night at Chain O’Lakes State Park, near the Wisconsin border in Illinois. There are extensive wetlands in that park as well as dry upland areas. Though my singing insect search for the most part turned up common, expected species, I have hope for better results in a future wetter year. In the extensive upland restored prairie areas Allard’s ground crickets were the main daytime singers. In a lower, damper, goldenrod-dominated patch were some black-horned tree crickets (or, possibly, their sibling species the Forbes’s tree cricket).

The heavy but well separated basal spots on the antennae plus the dark antennal color identify this as a black-horned.

In a higher-quality prairie patch not far from some trees I found a bush katydid.

The species cannot be determined from this angle.

A quick capture made for an easy identification.

The brown, curved ovipositor distinguishes the female fork-tailed bush katydid.

Later, after dark, I heard a number of sword-bearing coneheads in the prairie areas.

This species, with its distinctive sewing-machine song, is common in meadows and prairies of the region.

Wetlands are abundant at this park, and some appear to be relatively high in quality.

Pike Marsh

The singing insects were of common species for the most part.

The slender meadow katydid is abundant in wet places.

The most conservative species I found at Chain O’Lakes was a female long-tailed meadow katydid.

This was the first green-legged female of this species I have seen. Usually they are all brown.

I will return to that park in a wetter year.

Chasing Coneheads 1: Illinois Beach State Park

by Carl Strang

Last winter I was contacted by Gideon Ney, a graduate student at the University of Missouri in the laboratory led by Johannes Schul. Their focus is the evolutionary relationships among katydids, and members of that research group have published significant analyses of coneheaded katydids, genus Neoconocephalus. One species which they had not yet studied is the slender conehead, Neoconocephalus lyristes, and Gideon found my post in this blog on that species last winter. There I mentioned my interest in finding lyristes, and we corresponded through the succeeding months as we planned our hunt for it. Gideon and another student from that lab, Nathan Harness, who is beginning a study of Orchelimum meadow katydids, came up last week. They started at Chain O’Lakes State Park in Illinois, and I joined them the next day at Illinois Beach State Park. We set up camp, did some scouting, then relaxed in the afternoon.

Gideon and Nathan enjoy the inland sea waters of Lake Michigan.

Coneheads for the most part sing after dark, and we began to drive the roads with windows and ears open as dusk deepened to night. The first conehead we found was the sword-bearing conehead, a common species of dry meadows.

The face of a sword-bearing conehead. The English name for the group refers to the structure protruding from the top of the head between the eyes. In this species the cone has a crescent-shaped black mark near the tip.

The sword-bearing conehead is named for the female’s ovipositor. Gideon caught one and held it for my photo.

Here you can see that the ovipositor extends slightly beyond the wings.

Most of the coneheads we found had unornamented cones like those of the robust conehead, which I found at Kankakee Sands last month. However, the song was not nearly as loud, and the tentative conclusion was that these belonged to a different species, the false robust conehead. We heard a good variety of singing insects, but no slender coneheads, and so made plans to shift to Indiana Dunes National Lakeshore the next day (to be continued).

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.

Coneheads

by Carl Strang

The singing insect season is drawing to a close, and I have not mentioned one group to which I devoted some attention this season. The coneheaded katydids are a fairly diverse group of relatively large katydids characterized by cone-shaped structures that rise from the tops of their heads.

Nebraska conehead b

This is a Nebraska conehead. Its song consists of loud, shrill buzzes about 1.5 seconds long, with 1-second pauses between. It sings starting at dusk, in habitat that in my experience always has bushes and usually trees. The only location I have found so far with more than 3 or so singing individuals is Parson’s Grove at Danada Forest Preserve. The scattered bushes against the savanna edge seem to be ideal for this species.

There are two common, widely distributed coneheads in DuPage County’s meadows and prairies. The first to start singing, in the second half of July, is the sword-bearing conehead.

Sword-bearing 2b

Its rapidly ticking song has been compared to the sounds of a distant steam engine or a sewing machine. The other common meadow species is the round-tipped conehead.

Round-tipped conehead 3b

As you can see, these katydids look much alike. The round-tipped has a relatively short cone with a small black area at the tip (compare to the longer cone with a nearly all black surface on the Nebraska conehead, above).

Round-tipped conehead 5b

This one is more of a late season species, starting up in the second half of August and continuing through October. Its song to my ear is much like that of the Nebraska conehead, except that it has very long continuous buzzes rather than interrupted ones.

The possibility that I need to clear up is whether the robust conehead also is present. Its song is continuous, like that of the round-tipped, but reportedly is much louder and at a lower pitch. Its similar cone typically lacks the black tip, and body size is larger. I may have heard some of these at night while driving in past years, but so few in 2009 that I will have to hold this possibility for investigation until next year.

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