Brachoria virginia, , Mercer County, Camp Creek, 2010

Marek, Paul E., 2010, A revision of the Appalachian millipede genus Brachoria Chamberlin, 1939 (Polydesmida: Xystodesmidae: Apheloriini), Zoological Journal of the Linnean Society 159 (4), pp. 817-889 : 877-880

‘THE VIRGINIA MIMIC MILLIPEDE’

( FIG. 36A–D, FIG . 41S–U)

Diagnosis: Adult males of B. virginia are distinct from other Brachoria species based on the combination of: Exoskeleton. Caudolateral corners, paranota 7–11 rounded 90° angles, lateral margins 1–6 angled cephalically (lateral margins 1–4 angled stronger than others). Caudolateral edge of collum strongly angled cephalically at 35° from posterior medial margin. Gonopods. Gonopodal acropodite very narrow, half width of tibia on leg pair 9, slightly bulged beyond cingulum, distally acuminate. Acropodite curved medially in an oval-shaped form with foci pointing laterally; not curved anteriorly as in other species ( Fig. 36D ). Arc immediately distal beyond cingulum curved medially ( Fig. 36A ). Acropodal apex projecting laterally, directed towards acropodite base ( Fig. 36A ). Apex gradually tapered distally ( Fig. 36B ). Anterior edge of acropodite distal to postcingular bulge, slightly wavy. Apex tip curved 90° laterally, and bent 90° dorsally, thin fin-shaped ( Fig. 36D , arrow), ~1/20 length of acropodite ( Fig. 36B , arrow). Note: there are three very different colour morphs of B. virginia with considerable variation amongst them ( Fig. 41S–U). Colour can vary wildly and be completely misleading for identification purposes.

Description: Holotype (♂) FMNH-INS43084 – measurements: BL = 46.38. CW = 7.81. IW = 5.30. ISW = 1.60. B10W = 10.85. B10H = 6.50. AL = 2.05. Head: antennae extending backwards to middle of third tergite, relative antennomere lengths 2> 5> 3> 4> 6> 1> 7. Tergites: collum with straight cephalic edge, tapering laterally. Caudolateral edge of collum strongly angled cephalically at 35° from posterior medial margin. Collum with faint carina present on anterolateral margins, absent medially. Paranota 7–11 with caudolateral corners rounded 90° angles, lateral margins 1–6 angled cephalically, 1–4 angled stronger than others. Paranotal dorsal surface loosely wrinkled, appearing leathery. Ozopores orientated dorsolaterally. Paranota with anterodorsal corner flattened. Gonapophyses goblet-shaped apically, hirsute. Pleural tubercle absent. Sterna without posterior-projecting spines, with flat caudal margin. Sterna 2–8 sparsely setose (Ể ten setae), sterna 9–18 without setae, ventral surface smooth. Gonopods: in situ configuration – acropodite projected ventrally and curved medially in an oval-shaped form with foci pointing laterally ( Fig. 36D ). Acropodite curved cephalically, as in other species. Terminal arc (i.e. medial focus) of acropodite orientated laterally. Acropodal apex projecting laterally, directed towards acropodite base. Left, right acropodites crossed midlength, not appearing intertwined. Telopodites – prefemur with thorn-shaped prefemoral process, with apex tapered gradually to sharp curved point, ~one-eighth of length of acropodite, one third of its width at its base. Gonopodal acropodite very narrow, half width of tibia on leg pair 9, slightly bulged beyond cingulum, distally acuminate. Acropodite with ventrobasal surface facing medially, flat (slightly convex) without flange or swelling. Acropodite base without spines on dorsal surface. Acropodal basal and apical ventral surfaces coplanar, apical surface facing medially; anterior twist absent, not curved anteriorly as in other species. Acropodal ventral surface not swollen, smooth. Acropodite with midlength transverse groove, cingulum. Acropodite with postcingular region bulged, about 1.33 ¥ wider than width of pre-cingulum at its widest section. Postcingular region of acropodite without ventromedial or lateral teeth. Acropodal apex orientated laterally. Acropodite with postcingular region ~half its total length. Anterolateral edge of acropodal postcingular region (distal to bulge) slightly wavy. Acropodite with an undivided apex. Apex gradually tapered distally. Apex tip curved 90° laterally, and bent 90° dorsally, thin fin-shaped, ~1/20 length of acropodite ( Fig. 36B , arrow). Paratype (♀) FMNH-INS43086 – measurements: BL = 44.94. CW = 8.70. IW = 6.25. ISW = 2.09. B10W = 12.30. B10H = 8.50. Cyphopods: cyphopods with receptacle (at its greatest breadth), very small, half prefemur length. Receptacle pebble-shaped, convex dome top facing dorsally. Cyphopodal valves nearly symmetric (left valve slightly more convex). Cyphopods with valvular suture facing anteriorly.

Variation: Brachoria virginia is known only from the type locality and five specimens (3♂ and 2♀ from type series collected in 2007). There is strong variation in coloration amongst these specimens with three very different morphs: two-spotted ( Fig. 41S), red paranotal and anterior collum spots, legs orange; three-spotted ( Fig. 41U), yellow paranotal, metatergal, anterior and posterior collum spots, legs; twospotted ( Fig. 41T), orange paranotal and anterior collum spots, legs. There is negligible variation in measurements amongst these specimens; however, one male was much smaller in body length compared to the other two. Measurements: ♂ (N = 3) BL = 40.48–49.52 (45.46/4.59). CW = 7.35–8.33 (7.83/ 0.49). IW = 4.90–5.60 (5.27/0.35). ISW = 1.55–1.72 (1.62/0.09). B10W = 9.69–11.30 (10.61/0.83). B10H = 5.60–6.95 (6.35/0.69). ♀ (N = 2) BL = 44.94, 51.41 (48.18). CW = 8.70, 8.73 (8.72). IW = 6.20, 6.25 (6.23). ISW = 2.02, 2.09 (2.06). B10W = 12.10, 12.30 (12.20). B10H = 8.20, 8.50 (8.35).

Ecology: Brachoria virginia specimens were collected during the day (11:00) in a forest predominately comprising maple trees. Individuals were found beneath layers of decomposing leaf material near Ketron Branch, within about 5 m of the water. No other xystodesmids were encountered sympatrically at this locality. Note: individuals of B. virginia may be confused in the field with A. v. corrugata because of similarity in colour patterns and overlap in distribution, but can be distinguished by the presence of the following characters (viewed with a 20¥ loupe): acropodite with midlength transverse groove, cingulum; acropodite bulged beyond cingulum, 1.33 ¥ wider than width of pre-cingulum at its widest section; acropodite curved medially in an oval-shaped form with foci pointing laterally ( Fig. 36D ); not curved anteriorly; apex tip curved 90° laterally, and bent 90° dorsally, thin fin-shaped, ~1/20 length of acropodite ( Fig. 36B ); acropodite not circular as in A. v. corrugata .

Distribution: Known only from the type locality. The closest known Brachoria species , B. mendota , occurs about 10.5 air km north on Clinch Mountain in the town of Mendota, Washington County, Virginia.

Material examined: Type specimens. ♂ holotype ( FMNH-INS43084 *: GU150157 ), 1♂, 1♀ paratypes ( FMNH-INS43085 , 86 ), 1♂, 1♀ paratypes ( VMNH, SPC0001093 , 1095 ) from Virginia, Scott County , US-421, Ketron Branch valley , about 2.2 rd km east of junction with VA-617, about 2.0 rd km west of county line (36.63050°N, - 82.32248°W, 496 m), 10.v.2007, 11:00 (colls: P. Marek, C. Hall, D. and M. Beamer) .

Etymology: This species is named after the great Commonwealth of Virginia. (The specific name is a noun in apposition to the generic name derived from the type locality).

BRACHORIA VIRIDICOLENS ( HOFFMAN, 1948) ‘THE GREEN RIVER MIMIC MILLIPEDE’

( FIG. 37A–D, FIG . 41V–X)

Tucoria viridicolens Hoffman, 1948: 349 . Brachoria viridicolens – Keeton, 1959.

Diagnosis: Adult males of B. viridicolens are distinct from other Brachoria species based on the combination of: Exoskeleton. Caudolateral corners, paranota 1–4 rounded, lateral margins 1–4 angled cephalically. Caudolateral edge of collum strongly angled cephalically at 35° from posterior medial margin. Gonopods. Gonopodal acropodite bulky, subequal in width to tibia on leg pair 9, swollen distally beyond cingulum, comma shaped ( Fig. 37B ). Prefemur without prefemoral process. Acropodite curved medially in D-shaped form ( Fig. 37D ). Acropodite curved cephalically 45° in C-shape form ( Fig. 37B ). Arc immediately distal beyond cingulum orientated dorsally. Swollen acropodite distal beyond cingulum comma shaped ( Fig. 37B ). Three–four stout sawtooth-shaped teeth dorsally on comma one-third of length distal from cingulum ( Fig. 37A, B, D , top arrows). Acropodal apex nubbin-like, projecting laterally from tip of swollen acropodite ( Fig. 37A, B, D , bottom arrows). Note: there are three colour morphs ( Fig. 41V–X) with considerable variation amongst them (hence the specific epithet). Colour can vary wildly and be completely misleading for identification purposes.

Variation: Brachoria viridicolens is known only from the type locality and 14 air km east by the Green River . It is only known from five specimens (1♂, the type, collected in the 1800s and 2♂ and 2♀ collected in 2005). There is extreme variation in coloration. Amongst four specimens there are three colour morphs: (1) three-spotted ( Fig. 41V), yellow (5Y 8.5/ 10) paranotal spots, anterior collum stripe, legs; metatergal spots (sometimes very faint) light orange (7.5YR 7/10); (2) three-spotted ( Fig. 41W), pink (7.5 R 6 /10) paranotal and metatergal spots, anterior collum stripe, legs; (3) combined striped and three-spotted ( Fig. 41X), yellow paranotal and metatergal spots, stripes, legs. Measurements: ♂ (N = 3) BL = 39.81– 43.33 (41.28/1.83). CW = 7.60–8.36 (7.95/0.38). IW = 4.94–5.29 (5.09/0.18). ISW = 1.50–1.60 (1.53/ 0.06). B10W = 9.60–10.61 (9.97/0.55). B10H = 6.01– 6.60 (6.24/0.32). ♀ (N = 2) BL = 40.74, 44.07 (42.41). CW = 7.73, 8.00 (7.87). IW = 5.60, 5.77 (5.69). ISW = 1.66, 1.80 (1.73). B10W = 9.95, 11.00 (10.48). B10H = 7.10, 7.50 (7.30) .

Description: Male described by Hoffman (1948); rediagnosed by Keeton (1959).

Ecology: Brachoria viridicolens specimens were collected during the day and evening (14:00 and 19:00) in a maple forest near a small shaded tributary of Green River and in a dry oak forest next to Green River. Individuals were found beneath layers of decaying leaf material, predominately maple and oak. At the first locality, specimens were collected on the banks of a stream beneath stacks of maple leaves; whereas at the second locality, specimens were collected in moist depressions filled with decaying leaves at the bottom of a gully in an oak forest. One other xystodesmid encountered sympatrically at this locality is A. v. corrugata , which appears similar in coloration to the B. viridicolens three-spotted-striped morph. Note: individuals of B. viridicolens may be confused in the field with A. v. corrugata because of similarity in colour patterns, but can be distinguished by the presence of the following characters (viewed with a 20¥ loupe): acropodite with midlength transverse groove, cingulum; acropodite bulky, about equal to width of tibia on leg pair 9, swollen beyond cingulum, comma shaped ( Fig. 37B ); acropodite not circular, without an acuminate apex as in A. v. corrugata .

Distribution: Known only from the type locality and 14 air km east on the western banks of the Green River. The closest known Brachoria species , B. electa and B. kentuckiana , occur about 80 air km north-east in Mercer County and about 80 air km south-east in Pulaski County, Kentucky, respectively.

Material examined: Type specimens. 1♂ holotype ( USNM) from Green County, Kentucky, Greensburg, Trace Creek , 15.vii.?, year not indicated on label, probably between 1889 and 1929. (coll: H. Garman) (vidi). Nontype specimens. Kentucky: 1♂ ( SPC000606 *: EU127859 ), 1♀ ( SPC000558 ), Green County , Greensburg , Bluff Boom Rd. , about 1.0 rd km north-east of junction with KY-70, Green River tributary (37.27314°N, - 85.49036°W, 200 m), 25.vi.2005, 14:00 (coll: P. Marek). 1♂ ( SPC000610 ), 1♀ ( SPC000611 ), Taylor County , Green River Lake State Park , Deer Creek Trail, near trailhead (37.2789°N, - 85.3296°W, 222 m), 25.vi.2005, 19:00 (coll: P. Marek) .

Figures

Figure 36. Brachoria virginia sp. nov. A–D, holotype specimen gonopods: A, left male gonopod, anterior view; B, left male acropodal apex, magnified; C, left male gonopod, medial; D, same, posterior (acropodite length = 2.05 mm).

Figure 37. Brachoria viridicolens (Hoffman, 1948). A–D, holotype specimen gonopods: A, left male gonopod, anterior view; B, left male acropodal apex, magnified; C, left male gonopod, medial; D, same, posterior (acropodite length = 1.75 mm).