Noteworthy records of the millipeds, eurymerodesmus angularis and E. mundus (Polydesmida: Eurymerodesmidae), from northeastern and westcentral texas.
Between October 2001 and May 2003, locations (primarily in State Parks) within 24 Texas counties (Bosque, Bowie, Brown, Cass, Coryell, Dallas, Delta, Fannin, Freestone, Harrison, Hopkins, Jack, Johnson, Limestone, Marion, Morris, Parker, Red River, Shackleford, Somervell, Taylor, Titus, Tom Green and Travis) and Caddo Parish, Louisiana, were examined for millipeds in general and eurymerodesmids in particular. Individuals were encountered primarily in damp spots off park trails by overturning decaying logs and leaf litter with potato rakes. Occasional specimens were collected by peeling bark off fallen trees and rotting stumps. At each locale, specimens were placed in individually labeled vials containing 70% ethanol and returned to the laboratory for identification. Specimens were identified by examining the male genitalia. In eurymerodesmids both the gonopods and gonopodal apertures in males hold taxonomic utility as do the female cyphopods, which possess projections and other unique morphological features. Voucher specimens were deposited in the invertebrate collection of the North Carolina State Museum of Natural Sciences.
Several specimens of E. mundus were found during the study period in Texas; data are as follows:
Cass County, 8.1 mi (12.9 km) S Linden, along Yellow Poplar Trail off US Hwy. 59, 5[male], 3[female], 12 November 2001 and 26 November 2002. Dallas County, Cedar Hill State Park, DORBA and Talala Trails, 5[male], 4[female], 21 January and 16 November 2002. Morris County, Daingerfield State Park, Dogwood Camping Area, [male], [female], 26 November 2002. Taylor County, Abilene State Park, Elm Creek Nature Trail, 4[male], [female], 17 November 2001. Titus County, Lake Bob Sandlin State Park, 3[male], 2[female], juv., 21 December 2002.
Eurymerodesmus mundus is readily recognized by the large, hirsute, clavate lobes on the caudal margin of the gonopodal aperture (Shelley 1990). Shelley speculated that the lobes must alter the millipeds' posture and locomotion because they are so disproportionately large in relation to the rest of the body that they would otherwise scrape the substrate or become impaled. The published record from Grayson County by Shelley was inadvertently omitted from the text; its data are Grayson County, Sherman, in storm cellar, 4[male], 7[female], 3 October 1967, M. Cundliff (Florida State Collection of Arthropods, Gainesville). The sites in Titus and Taylor counties are some 350 miles (563 km) apart, so E. mundus thus occupies the entire breadth of the family's distribution across northern Texas. The species also inhabits a variety of biotopes as habitats at these locales are quite different. The site in Cass County is a climax forest on acreage owned by International Paper Company that consists primarily of pines, yellow poplar and various oak species, while the sites in Morris and Titus counties are within state parks and comprised of mixed hardwoods. However, at the Dallas and Taylor County sites, the dominant trees are live oak, mesquite and eastern red cedar. In addition, the site in Dallas County includes trails situated near native tall grass prairie habitat. Eurymerodesmus mundus ranges northward to Nebraska, and in the "Ark-La-Tex" region (Fig. 1). Its occurrence in southwestern Arkansas (McAllister et al. 2002a) and northeastern Texas near the Louisiana state line suggest potential discovery in northwestern Louisiana (perhaps Bossier and/or Caddo parishes), which would constitute a new state record. Interestingly, a large female Eurymerodesmus resembling E. mundus was collected by the senior author on 6 January 2003 in the vicinity of Oil City, Caddo Parish; however, an authentic male of E. mundus is necessary for specific identification.
[FIGURE 1 OMITTED]
Specimens of E. angularis were also encountered in three counties in the northeastern corner of Texas, confirming Shelley's prediction (1990) of discovery in this area. It represents a new species for Texas and the tenth species of Eurymerodesmus in the state. Data are as follows:
Bowie Co., 5 mi (8 km) W Texarkana, along County Road 1217 off FM 991, [male], juv., 10 October 2001; S of Texarkana (Liberty Eylau) off FM 558 along County Road 1370, 10[male], 6[female], 11 October 2001 and 2[male], 19 December 2001; Texarkana, Texas A & M University campus off Robison Rd., 3[male], 5 November 2001. Cass Co., Atlanta, Ellington Clinic off U.S. Hwy. 59, 2[male], 7 November 2002. Marion Co., Jefferson, 2997 FM 728, Cypress Bend Adventist Elementary School, 3[male], 23 October 2002, and [male], 4 mi (6.4 km) NW Jefferson, 9 November 2002. All specimens above represent new county records.
Habitat at these sites is typical east Texas pineywoods, and specimens were encountered while moving along the ground after brief fall showers. Eurymerodesmus angularis is a highly variable and widely ranging species (Fig. 1), and the most proximate prior record to this current study is that from the vicinity of Myrtis, ca. 30 miles (48.3 km) NNW Shreveport, Caddo Parish, Louisiana (Shelley 1990). Despite several efforts, no specimens of E. angularis were encountered in the vicinity of Caddo Lake State Park in adjacent Harrison County, but its presence is anticipated during the cooler and wetter months of fall and winter. Shelley (1990) depicted four gonopodal variants of E. angularis that he considered to be conspecific, and the northeast Texas form is that found in Caddo Parish, with lightly sinuate gonopodal acropodites and an aperture in which the caudolateral "pouch" flares strongly laterally.
To date little milliped sampling has taken place in northeast Texas (Stewart 1969). In addition, northeast Texas likely forms the western distribution boundary for a number of "eastern" diplopods and hence justifies more intensive investigation. Recent studies in proximate parts of Arkansas and Oklahoma produced several important discoveries (McAllister et al. 2002a; 2002b; 2003a; 2003b; Shelley et al. 2003), lending credence to this statement. Focused studies on the northeast corner of Texas may be similarly profitable and are a primary objective of future research.
The senior author thanks TAMU-T, particularly Drs. J. Johnson and G. Mueller for providing Faculty Senate Research Enhancement Grants nos. 140000 and 200900 to fund a portion of this study. We also thank James T. McAllister, III (Brookhaven College, Dallas, Texas), and Nancy Solley (TAMU-T) for assistance in collecting.
McAllister, C. T., C. S. Harris, R. M. Shelley & J. T. McAllister, III. 2002a. Millipeds (Arthropoda: Diplopoda) of the Ark-La-Tex. I. New distributional and state records for seven counties of the West Gulf Coastal Plain of Arkansas. J. Arkansas Acad. Sci., 56:91-94.
McAllister, C. T., R. M. Shelley & J. T. McAllister, III. 2002b. Millipeds (Arthropoda: Diplopoda) of the Ark-La-Tex. II. Distributional records for some species of western and central Arkansas and eastern and southeastern Oklahoma. J. Arkansas Acad. Sci., 56:95-98.
McAllister, C. T., R. M. Shelley & J. T. McAllister, III. 2003a. Millipeds (Arthropoda: Diplopoda) of the Ark-La-Tex. III. Additional records from Arkansas. J. Arkansas Acad. Sci., 57:(In press).
McAllister, C. T., R. M. Shelley & J. T. McAllister, III. 2003b. Millipeds (Arthropoda: Diplopoda) of the Ark-La-Tex. IV. New geographic distribution records from southcentral and southeastern Oklahoma. Proc. Oklahoma Acad. Sci., 83:(In press).
Shelley, R. M. 1990. Revision of the milliped family Eurymerodesmidae (Polydesmida: Chelodesmidea). Mem. Amer. Entomol. Soc., 37:1-112.
Shelley, R. M., C. T. McAllister & S. B. Smith. 2003. Discovery of the milliped Pleuroloma flavipes Rafinesque in Texas, with a disjunct record from Louisiana, and new localities from west of the Mississippi River (Polydesmida: Xystodesmidae). Entomol. News 114:(In press).
Stewart, T. C. 1969. Records of millipeds in twenty five northeast Texas counties. Texas J. Sci., 20(4):383-385.
Chris T. McAllister, Rowland M. Shelley* and Dawn I. Moore
Department of Biology, Texas A & M University-Texarkana Texarkana, Texas 75505 and *Research Laboratory, North Carolina State Museum of Natural Sciences 4301 Reedy Creek Road, Raleigh, North Carolina 27607
CTM at: firstname.lastname@example.org
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|Title Annotation:||General Notes|
|Author:||McAllister, Chris T.; Shelley, Rowland M.; Moore, Dawn I.|
|Publication:||The Texas Journal of Science|
|Date:||Feb 1, 2004|
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