More Prairie Meadow Katydids

 

by Carl Strang

Last year I first encountered what I thought were prairie meadow katydids (Conocephalus saltans), in my survey of the Chicago region’s singing insects. Further study confirmed my identifications, and set the stage for finding the species in a third location in 2017. On September 2, Lisa Rainsong and I ran into a cluster of small meadow katydids at the Pembroke Savanna Nature Preserve, a Nature Conservancy savanna in eastern Kankakee County. These proved to be a mix of two species, straight-lanced meadow katydids (Conocephalus strictus) and prairie meadow katydids.

A scene at Pembroke Savanna, which I regard as the most beautiful site in the 22-county Chicago region.

Finding these two similar species together provided us with a tutorial in distinguishing them. Most of the individuals were females, and the contrast in their ovipositors could not be starker. Those of the prairie meadow katydids had a slight curve, and were much shorter.

Female prairie meadow katydid, Pembroke

Straight-lanced females have straight ovipositors that typically are as long as their bodies, or longer.

Female straight-lanced meadow katydid, Judy Burton Nature Preserve, Indiana. This one is atypical in having long wings. Most have wings about a third the length of the abdomen.

Prairie meadow katydids have wings that usually are only a quarter of the abdomen length. The knob at the tip of the head is more pronounced, though both species have this knob. The sides of the hind femurs also are different. In prairie meadow katydids there is a pattern of thin lines that resemble a ladder, on a brown leg. There usually is a diffuse black line that appears to be within the straight-lanced meadow katydid’s green hind femur. Some variation occurs in many of these features, so I advise caution and the examination of several individuals within a population.

Males have been fewer in both species, in the populations I have examined.

 

Male prairie meadow katydid, Pembroke

Again, the more exaggerated head knob, shorter wings, and different femur pattern are helpful. Cerci are very different in the two species, also.

Male straight-lanced meadow katydid, from another eastern Kankakee County savanna site.

I did not get a photo showing the prairie meadow katydid’s cerci, but their ends are much shorter, proportionately, than those of the straight-lanced in the photo, comparable in length to the teeth, and bend outward somewhat rather than being straight.

A final curious note from Pembroke was that the prairie meadow katydids were all brown, as the photos show. The straight-lanced meadow katydids had considerable amounts of green color. This may have been the result of local selective pressures, as this is not a consistent difference across the species’ ranges.

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Rounding Out Conehead Maps

by Carl Strang

This has been a good year in my quest for coneheads. The coneheaded katydids of genus Neoconocephalus are represented by six species (historically, seven) in the 22 counties I define as the Chicago region.

 

Sword-bearing conehead. This katydid is named for the female’s long ovipositor.

Prior to 2017, I had found sword-bearing coneheads (N. ensiger) in every county. In a recent post, I detailed the completion of the search for Nebraska coneheads (N. nebrascensis), which can be found in all but the three Wisconsin counties of the region. In another post I described progress in finding slightly musical coneheads (N. exiliscanorus).

 

Robust conehead in singing posture

 

Today I can report that I now have found two more species in all 22 counties: the robust conehead (N. robustus), and the round-tipped conehead (N. retusus). Though it extends into Wisconsin, the round-tipped thins out rapidly south to north, and some effort was needed to find a singing round-tipped conehead in the southern portion of Racine County, the region’s northernmost county.

 

Round-tipped conehead. The shape of the cone and the amount of black pigmentation help in species identification. The large jaws help them with their diet of seeds, and teach researchers to use caution in handling them.

The sixth species is the marsh conehead (N. palustris), which so far I have found only in Porter County, Indiana. Though I continue seeking the slender conehead (N. lyristes), I fear that it is extinct in the region.

 

Slender conehead. This museum specimen from the early 20th Century was collected in what is now Illinois Beach State Park. I have failed to find the species in my thorough exploration of its habitats there.

Wetland Singing Insects Update

by Carl Strang

For years, now, my biggest conservation concern among the singing insects has been in the wetlands. Though our historically abundant prairies in the Chicago region were diminished nearly to nothing by 19th– and 20th-century agriculture, preservation and restoration projects across the region have halted and, to a small degree, reversed that trend. The same could be said for savannas, and our forests did not suffer as much.

Wetlands, like prairies, declined thanks to agriculture, but a new challenge continues to threaten their integrity: invasive wetland plants. Four of these are especially problematic: common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), hybrid cattails (Typha x glauca), and purple loosestrife (Lythrum salicaria). These plants, released from consumers and competitors, have displaced the diverse native species in a large and increasing portion of our wetland acreage. The loss of native wetland grasses, especially, appears to account for the difficulty I am experiencing in finding wetland katydids.

Reed canary grass

Two species that were here historically, I have not found at all: the delicate meadow katydid (Orchelimum delicatum), and the slender conehead (Neoconocephalus lyristes). In the past these were known to occur in four and three, respectively, of the Chicago region’s 22 counties, and I am nearly out of places to check where they might still live. The stripe-faced meadow katydid (O. concinnum), once found in 8 of the counties, appears to be down to a single population at Illinois Beach State Park.

Stripe-faced meadow katydid

Two wetland katydids are doing well. Gladiator meadow katydids (O. gladiator) and black-legged meadow katydids (O. nigripes) are tolerant of the invasive plants, and remain common in every county.

That leaves an in-between category of wetland singing insects that apparently are limited to invasives-free wetlands, and are managing to hang on in a few to several sites. Northern mole crickets (Neocurtilla hexadactyla) occur in wet prairies as well as marshes. In 2017 I added records for two more sites, one of which represented an additional county record. To date I have found them in 10 counties, and remain optimistic that I can add more populations to the inventory.

Dusky-faced meadow katydids (O. campestre) historically were ubiquitous in our marshes. To date I have found them only in marshes with minimal impact by the invasive plants. These katydids seem able to persist in relatively small wetland areas, however, and each year I have been able to add new populations to my list. In 2017 I found them in the Indiana Kankakee Sands preserve, adding Newton County to the record, and in the Tefft Savanna preserve in Jasper County, also a county record. That brings to seven the number of counties where I have found the species, but there are seven more where it once lived, but where my search has been unsuccessful. Dusky-faced meadow katydids also proved this year to be abundant in the panne wetlands at West Beach in the Indiana Dunes National Lakeshore. That was a good find, but I had hoped for delicate meadow katydids there.

Female dusky-faced meadow katydid, Tefft Savanna

Finally, this year I added a third population and county for the nimble meadow katydid (O. volantum). They were singing from arrowheads (Sagittaria sp.) mixed with cattails along Grant Creek in the Midewin National Tallgrass Prairie. That find was made from a kayak, and that is the vehicle from which further searching for the species will need to happen, as this species likes plants growing in relatively deep water. Some places which historically held nimble meadow katydids no longer have them, but several other sites remain for me to check in future years.

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