black-legged meadow katydid
Orchelimum nigripes Scudder 1875

map
male
portrait
male
 
male hiding
male cercus
forewing movement  
 

21 s of calling song [1.75MB]; male from Shelby Co., Ohio; 24.0°C. (WTL262-8)


Waveform of 6 s of calling at 24.0°C (from WTL262-8). Peak frequency ca. 11 kHz.
Click on first half of waveform to hear graphed song.
Click on second half of waveform to expand last tick and beginning of last buzz.

Remarks:  Leo Shapiro, who published on his wide-ranging studies of the relationship between Orchelimum nigripes and O. pulchellum in 1998, 2000, and 2001, wrote this update for SINA in December 2005:

Orchelimum nigripes and O. pulchellum are clearly closely allied katydids. They are morphologically and genetically very similar (although clearly distinct over most of their distributions) and no differences are known in their ecology or song despite extensive field experience by several observers. (However, neither ecology nor song have yet been rigorously compared.)

The big picture is that O. nigripes (map) and O. pulchellum (map) are distributed west and east, respectively, of the Appalachian Mountains from the Great Lakes to the Gulf Coast and along the Atlantic Coastal Plain from New York to the Florida Keys, although these katydids are not found in the Appalachians themselves. South of the Appalachians, Shapiro (1998) found that the two taxa meet in a very broad zone of intergradation. However, O. nigripes complicates this picture a bit. Orchelimum nigripes has become established in at least one area east of the Appalachians, in the Potomac River basin, where it has completely replaced O. pulchellum along the river corridor above Washington, D.C., from at least Great Falls to Roosevelt Island (Shapiro 1998). Based on a comparison of current distributions with museum specimens collected from specific sites during the first half of this century and with an early annotated list of the Orthoptera of Plummer's Island, MD (McAtee and Caudell 1918) it appears that O. nigripes has appeared (or, at least, become established) along the Potomac River quite recently, within the last 50-75 years or less.

My examination of museum specimens in the early 1990s found that at least five typical-looking O. nigripes (deposited at the USNM) were collected by Henry Fox in 1913 near the Rappahannock River in Tappahannock, VA (~175 km south of D.C.). However, O. pulchellum were also collected here, also by Fox, in 1915 (specimens deposited at ANSP). In the mid-1990's, Shapiro (1998) found O. pulchellum to be abundant and widespread in this area but found no O. nigripes.

Single O. nigripes specimens were collected at Amherst, MA, in 1964 (deposited in the University of Massachusetts Entomology Department collection) and 1993 (collected by L. Shapiro, singing along a roadside at the edge of an agricultural field). Both of these specimens exhibited typical O. nigripes morphology and coloration and at least the 1993 specimen had characteristic O. nigripes allozyme alleles for MDH and IDH (Shapiro 1998). Perhaps a careful survey would turn up an established O. nigripes population around Amherst.

David Funk (Stroud Water Research Center) found what he believed to be O. nigripes and O. pulchellum occurring together in Kent County on the Eastern Shore of Maryland. Specimens he sent me appeared to be morphologically typical O. nigripes and O. pulchellum. Funk's apparently sympatric nigripes/pulchellum sites could be exceptionally interesting for anyone interested in initiating long-term ecological and/or behavioral and/or genetic studies of their interactions. At a minimum, further, geographically broad collecting in this area is critical. Funk also reports O. nigripes from southeastern Pennsylvania.

Responding to my inquiry in September 2005, Funk wrote:

It looks to me as though [O. nigripes] are getting more common in our area (southern Chester Co., PA). I collected some about an hour north of here in 2003, at Scott's Run Lake in French Creek State Park, Berks Co. PA (one male, one female, ix.10.2003...There were bunches of them a couple weeks ago at that same spot (didn't collect any, though)).

[The area where I have collected O. nigripes and O. pulchellum in sympatry] is really two general areas, about a mile or so apart in Kent Co., MD, between the towns of Betterton and Chestertown on the Eastern Shore. Two creeks enter the Bay there. One is Still Pond Creek. There is a spot near the mouth called Codjus Cove (it shows on some fine-scale maps). There are several little cattail marshes there where I collected both species starting in 1996. The other spot is at Churn Creek. Again, several small cattail and other marshes along a large cove (I don't know if it has a name) near the mouth. I had been visiting those creeks since the early 1980's (a friend of mine has a house there), but I never really paid attention to the Orchs prior to 1996, so I don't know if they were common there or not earlier. I do see that in my collection I have two nigripes (one male, one female) collected at Andelot (about 2 miles away) on August 21, 1984.

I would say nigripes is more common than pulchellum, at least in recent years.

As to fine scale distributions, they look like their habitat preferences are just about identical. Definitely both riparian, anyway.


I have encouraged Dave to collect series of both O. nigripes and O. pulchellum from both Kent County, MD, and southeastern Pennsylvania to deposit at ANSP, FSCA, and USNM, as well as to freeze some vouchers if possible for future genetic studies (he reports that he collected 19 nigripes and 7 pulchellum from these sympatric sites in 1995, 1996, 1997, and 1999, but must retain these as vouchers for his personal collection).

Finally, also in southeastern Pennsylvania, Rob Broekhuis recently discovered O. nigripes in Upper Macungie Township (~Allentown), Lehigh County, Pennsylvania, and collected one male singing on a soybean plant on 24 September 2005. I examined the specimen and it appeared to be a morphologically typical O. nigripes. Broekhuis previously posted a photo of another individual in this area, photographed 12 September 2004: http://bugguide.net/node/view/7010. It is not yet clear how abundant or widespread O. nigripes is in this area, or what the status of O. pulchellum is there. Hopefully someone can do some more extensive prospecting and collecting in this area in the near future. More information on the distribution of O. pulchellum and O. nigripes throughout Pennsylvania might conceivably provide insight on how O. nigripes reached the Potomac River.

If anyone has information to add to this summary of the status and distribution of O. nigripes and O. pulchellum, please forward it to both Leo Shapiro (lshapiro@umd.edu) and Tom Walker (tjw@ufl.edu). I (Leo) would be very happy to provide advice (and encouragement!) to anyone interested in pursuing further investigations of these wonderful beasts, whether through simple avocational scouting and collecting to improve our understanding of their distributions or as part of a formal research project.

In October 2006, Leo added this to his earlier update: "On 22 September 2006, John Himmelman encountered a population of singing O. nigripes at Hurd State Park in Haddam (Middlesex County), Connecticut. They were in grasses and sedges along the sandy banks of the Connecticut River. I have examined two adult male specimens and Himmelman has posted photos on a web site; all appear to be O. nigripes."

More information:  subfamily Conocephalinae, genus Orchelimum

References:  Cabrero et al. 1999; Feaver 1983, 1985; Shapiro 1995b, 1998, 2000, 2001.

Nomenclature:  OSF (Orthoptera Species File Online)