Brachoria sheari, Marek, 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 : 874-877

BRACHORIA SHEARI SP. NOV.

‘SHEAR’ S MIMIC MILLIPEDE’

( FIG. 34A–D, FIG . 41M–P)

Diagnosis: Adult males of B. sheari are distinct from other Brachoria species based on the combination of: Colour. Three-spotted ( Fig. 41M), yellow (or red, rare, Fig. 41N) paranotal, metatergal and collum spots, legs. Exoskeleton. Caudolateral corners, paranota 1–8 rounded, lateral margins 1–4 angled cephalically, 5–19 angled posteriorly (8–14 strongly so). Gonopods. Gonopodal acropodite bulky, three-fifths width of tibia on leg pair 9, bulged distally beyond cingulum, semiglobose ( Fig. 34C ). Acropodite curved medially in D-shaped form ( Fig. 34D ). Acropodite slightly curved anteriorly ( Fig. 34C ). Arc immediately distal beyond cingulum orientated dorsolaterally. Acropodal apex projecting laterally 90° from postcingular arc ( Fig. 34B , arrow). Acropodal apex 5 ¥ narrower than postcingular region, hook-shaped ( Fig. 34B , arrow). Note: although the most frequent colour pattern is three-spotted yellow ( Fig. 41M), there are four colour morphs with considerable variation amongst them ( Fig. 41M–P). Colour can vary wildly and be completely misleading for identification purposes.

Description: Holotype (♂) FMNH-INS43079 – measurements: BL = 44.72. CW = 8.70. IW = 5.60. ISW = 1.55. B10W = 11.50. B10H = 6.50. AL = 2.10. 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. Collum with thin carina present on anterolateral margins, absent medially. Paranota 1–8 with caudolateral corners rounded, lateral margins 1–4 angled cephalically, 5–19 angled posteriorly (8–14 strongly so). Paranotal dorsal surface tightly 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 four setae), sterna 9–18 without setae, ventral surface smooth. Gonopods: in situ configuration – acropodite projected ventrally, curved medially in D-shaped form ( Fig. 34D ). Acropodite slightly curved anteriorly ( Fig. 34C ). Terminal arc of acropodite orientated dorsolaterally. Acropodal apex projecting laterally 90° from postcingular arc ( Fig. 34B , arrow). Left, right acropodites crossed midlength, X-shaped. Telopodites – prefemur with thorn-shaped prefemoral process, ~one-tenth length of acropodite, one-third its width at its base. Gonopodal acropodite bulky, three-fifths width of tibia on leg pair 9, bulged distally beyond cingulum, semiglobose. Acropodite with ventrobasal surface facing medially, flat (slightly concave) without flange or swelling. Acropodite base without spines on dorsal surface. Acropodal basal and apical ventral surfaces not coplanar, apical surface facing dorsolaterally; anterior twist weak, acropodite slightly curved cephalically. Acropodal midlength ventral surface with slight ramp-like swell. Acropodite with midlength transverse groove, cingulum. Acropodite with postcingular region swollen, about 2.26 ¥ wider than precingulum at its widest section. Postcingular region of acropodite without ventromedial or lateral teeth. Acropodal apex orientated laterally ( Fig. 34B , arrow). Acropodite with postcingular region ~half its total length. Lateral edge of acropodal postcingular region without laminate flange. Acropodite with an undivided apex. Acropodal apex narrow, 5 ¥ narrower than postcingular region, hook-shaped ( Fig. 34 , arrow). Paratype (♀) FMNH-INS43082 – measurements: BL = 45.51. CW = 7.98. IW = 5.60. ISW = 1.70. B10W = 10.81. B10H = 7.25. Cyphopods: cyphopods with receptacle (at its greatest breadth) equal in width to prefemur length. Receptacle hatchet-shaped, widest edge (the blade) facing anterodorsally. Cyphopodal valves nearly symmetric (right valve slightly more convex). Cyphopods with valvular suture facing posteriorly.

Variation: Brachoria sheari is known only from three areas (the type locality, the ridge and on the north slope of Cumberland Mountain, near Shillalah Creek) and 11 specimens. There is some variation in coloration amongst these specimens with four morphs: (1) three-spotted ( Fig. 41M), yellow (10YR 3/14) paranotal, metatergal and collum spots, legs; (2) threespotted, yellow (10YR 7/14) paranotal spots, leg tips; orange (7.5YR 6/12) metatergal spots, leg bases; (3) three-spotted ( Fig. 41N), red (8.5R 5/14) paranotal, metatergal and collum spots, legs; (4) four-spotted ( Fig. 41P), yellow paranotal, metatergal, prozonal and collum spots, legs. Some three-spotted, yellow individuals have very faint metatergal spots, appearing two-spotted ( Fig. 41O). There is negligible variation in measurements amongst these specimens. Measurements: ♂ (N = 6) BL = 44.08–50.80 (46.37/2.79). CW = 8.04–9.33 (8.56/0.49). IW = 5.22–5.86 (5.50/ 0.26). ISW = 1.50–1.70 (1.56/0.07). B10W = 10.50–11.81 (11.11/0.48). B10H = 5.85–7.10 (6.40/ 0.44). ♀ (N = 5) BL = 44.09–49.35 (46.79/2.09). CW = 7.89–9.00 (8.27/0.45). IW = 5.60–6.01 (5.83/ 0.16). ISW = 1.70–1.83 (1.76/0.06). B10W = 10.81– 12.15 (11.43/0.56). B10H = 7.25–7.93 (7.60/0.28).

Ecology: Brachoria sheari specimens were collected during the day (12:06) in a forest comprising maple, sycamore, dogwood, oak, and buckeye trees. Individuals were found beneath layers of decomposing leaf material at the bottom of a dry streambed just east of the trail. Other xystodesmids encountered sympatrically at these localities are B. cedra , B. dentata , and A. v. corrugata . Note: individuals of B. sheari may easily be confused in the field with B. cedra , B. dentata , and A. v. corrugata as a result of very strong similarity in colour patterns, but can be distinguished from the other Brachoria by the diagnostic characters and from A. v. corrugata by the presence of the following characters (viewed with a 20¥ loupe): acropodite with midlength transverse groove, cingulum; acropodite bulky, three-fifths width of tibia on leg pair 9, bulged distally beyond cingulum, semiglobose ( Fig. 34C ); acropodal apex 5 ¥ narrower than postcingular region, hook-shaped ( Fig. 34B , arrow); acropodite not circular like in A. v. corrugata .

Distribution: Known only from four localities on Cumberland Mountain: two sites very close to each other on the Virginia side of the mountain at its base, one from the Ridge Trail on top of the mountain, and another on the Kentucky side of the mountain near Shillalah Creek. The closest known Brachoria species , B. cedra and B. dentata , co-occur with B. sheari and share a strong mimetic resemblance. This species was provisionally referred to as Brachoria species ‘n’ in Marek & Bond (2009).

Etymology: This species is named in honour of Professor William Shear of Hamden-Sydney College, Virginia. A mentor and friend who collected this species atop Cumberland Mountain while hiking its ridge trail and documenting the millipede biodiversity of the region. (The specific name is a genitive noun derived from the person who discovered it, Professor William Shear.)

Material examined: Type specimens. ♂ holotype ( FMNH-INS43079 *: EU127871 ), 2 ♂, 2 ♀ paratypes ( FMNH-INS43080-83 ), 1 ♂, 1 ♀ paratypes ( USNM, SPC001038 , 1037 ) from Virginia, Lee County, Cumberland Gap National Historical Park, Gibson Gap Trail , about 1.0 km north of junction US-58 (36.60764°N, - 83.62952°W, 396 m), 28.vii.2006, 12:06 (colls: P. and B. Marek). Nontype specimens. Kentucky: 1♀ ( MMC0373 ), Bell County, rhododendron cove east of Shillalah Creek trailhead (36.66770°N, -83.58262, 493 m), 1.x.2006, 14:30 (coll: P. Marek). Virginia: 1♂ ( PMLN0163 ), Lee County , Cumberland Gap National Historical Park, Ridge Trail between Gibson and Woodson Gaps (36.6373°N, - 83.6041°W), 6.ix.1970 (coll: W. Shear). 1♂ ( MMC0319 ), 1♀ ( MMC0325 ), Lee County , Cumberland Gap National Historical Park, Honey Tree Trail, 0.2 trail km east of junction with Gibson Gap Trail (36.6078°N, - 83.6322°W), 29.ix.2006, 11:00 (coll: P. Marek) .

BRACHORIA SPLENDIDA ( CAUSEY, 1942) ‘THE SPLENDID MIMIC MILLIPEDE’

( FIG. 35A–D, FIG . 41Q–R)

Cleptoria splendida Causey, 1942: 167 . Tucoria dynama Chamberlin, 1947 ; synonymized by Chamberlin & Hoffman, 1958. Brachoria splendida – Chamberlin & Hoffman, 1958. I agree with the synonymy of T. dynama with B. splendida . I have seen the type (ANSP) and agree with Chamberlin and Hoffman that it does not exhibit significant enough differences from B. splendida to warrant nomenclatural status.

Diagnosis: Adult males of B. splendida are distinct from other Brachoria species based on the combination of: Size. Body length on average larger than other species (♂ 47.69, ♀ 47.08). Colour. Three-spotted ( Fig. 41Q), yellow (pink or red, Fig. 41R) metatergal spots, paranotal spots, anterior and posterior collum spots (sometimes merged together in an hourglass shape), legs. Metatergal spots often notched anteriorly. Exoskeleton. Caudolateral corners, paranota 1–5 rounded, lateral margins 1–7 angled cephalically. Caudolateral edge of collum strongly angled cephalically at 35° from posterior medial margin. Gonopods. Gonopodal acropodite bulky, about equal to width of tibia on leg pair 9 (or slightly wider). Acropodite bulged distally beyond cingulum, narrowed, bulged again apically. Gonopodal sternal opening anterior margin excised semicircularly. Sterna on leg pair 7 recessed. Prefemur with small, stout thorn-like prefemoral process. Acropodite rotated 45° anteriorly on prefemur. Acropodite curved medially in D-shaped form ( Fig. 35D ). Acropodite posterior edge hirsute. Acropodite slightly curved anteriorly. Acropodite distal beyond cingulum S-shaped medially ( Fig. 35B ). Ventromedial surface (side opposite cingulum) of second postcingular bulge with thin, fin-shaped keeled carina ( Fig. 35D , top arrow). Acropodal apex nubbin-like, projecting dorsally from second bulge ( Fig. 35D , bottom arrow).

Variation: Brachoria splendida is known from several areas on Pine Mountain from Pine Mountain State Park to Bickford Nature Preserve. There is some variation in hue amongst individuals with two less frequent variants of the common yellow three-spotted morph ( Fig. 41Q): pink and red ( Fig. 41R). One yellow striped morph and one combined yellow striped/threespotted morph have been observed. Gonopodal form varies regionally. Some specimens with sawtoothshaped denticle on first postcingular bulge. However, all male specimens have distinctly S-shaped acropodites distal beyond cingulum ( Fig. 35B ). There is some variation in length and width measurements amongst these specimens. Measurements: ♂ (N = 7) BL = 44.10–51.84 (47.69/3.21). CW = 7.79–8.80 (8.39/ 0.39). IW = 5.23–5.70 (5.42/0.20). ISW = 1.55–1.71 (1.62/0.06). B10W = 10.30–11.30 (10.75/0.32). B10H = 6.45–7.15 (6.66/0.27). ♀ (N = 5) BL = 43.46– 49.74 (47.08/2.57). CW = 7.18–8.29 (7.87/0.42). IW = 5.39–5.98 (5.74/0.23). ISW = 1.61–1.83 (1.73/ 0.09). B10W = 9.86–11.40 (10.87/0.60). B10H = 6.80– 7.60 (7.28/0.31).

Description: Male described by Causey (1942); redescribed by Keeton (1959).

Ecology: Brachoria splendida is common in the Appalachian mixed mesophytic deciduous forests along Pine Mountain in Kentucky. It occurs in upland forests comprising oak, maple, tulip poplar, sycamore, and sassafras (e.g. Kentenia State Forest localities); and in moist lowland forests comprising hemlock, birch, umbrella magnolia, and rhododendron (e.g. Hemlock Garden, Cawood, and Blanton Forest). Other xystodesmids encountered sympatrically at these localities are: B. hansonia (Hemlock Garden) , B. flammipes (Cawood) , B. gracilipes and B. badbranchensis (Bickford Nature Preserve), and C. g. latassa (Kentenia State Forest localities). Note: individuals of B. splendida may be confused in the field with B. hansonia , B. flammipes , B. gracilipes , B. badbranchensis , and C. g. latassa as a result of similarity in colour pattern, but can be distinguished with the diagnostic characters for Brachoria species and by the presence of the following characters for C. g. latassa (viewed with a 20¥ loupe): dorsal cuticle smooth, not rugose like C. g. latassa; gonopodal acropodite bulky, about equal to width of tibia on leg pair 9; prefemur with small, stout thorn-like prefemoral process, not long, aciculate as in C. g. latassa; acropodite distal beyond cingulum S-shaped medially ( Fig. 35B ), not straight as in C. g. latassa; acropodite curved medially in D-shaped form ( Fig. 35D ); acropodite projecting straight from prefemur, whereas in C. g. latassa (and other individuals in the tribe Rhysodesmini ) acropodite is bent anteriorly at 90° from prefemur.

Distribution: Brachoria splendida occurs predominately on Pine Mountain, a linear mountain ridge, from Kentucky Ridge State Forest in Bell County to about 55 air km north-east to James E. Bickford Nature Preserve in Harlan County, Kentucky. Brachoria splendida also occurs in two apparently disjunct populations in Cumberland Gap National Park and in Daniel Boone National Forest, Leslie County. The closest known Brachoria species , B. hansonia and B. flammipes , co-occur with B. splendida in Pine Mountain State Park and Daniel Boone National Forest.

Material examined: Type specimens. ♂ holotype ( ANSP) from Bell County, Kentucky, Pine Mountain State Park , 16.vi.1940 (coll: N. Causey) (vidi). Nontype specimens. Kentucky : 1♂ (SPC000351), Bell County, Kentenia State Forest, south slope of Pine Mountain , KY-2010 (36.92733°N, - 83.19144°W, 710 m), 18.viii.2004, 15:30 (coll: P. Marek) . 1♂, 1♀ (A801), Bell County, Cumberland Gap National Historical Park, Tri-State Trail (36.60387°N, - 83.67395°W), 11.vi.1976 (coll: R. Shelley) . 1♂ (SPC000341*: DQ 490693 ) , 1♀ (SPC000345), Bell County, Pine Mountain State Park, Hemlock Garden Trail , near alternative return entrance (36.73537°N, - 83.73924°W, 430 m), 19.viii.2004, 11:00 (coll: P. Marek) . 1♂ (SPC000587), Bell County, Kentucky Ridge State Forest, Little Clear Creek Rd. , about 0.4 rd km south of junction with KY-190 (36.71808°N, - 83.72353°W, 392 m), 24.vi.2005, 9:00 (coll: P. Marek) . 1♀ (SPC000176), Harlan County, Pine Mountain, Blanton Forest State Nature Preserve, High Fork Branch , near campground ranger station (36.85942°N, - 83.38239°W, 430 m), 10.viii.2003, 13:00 (colls: P. Marek and D. Beamer) . 1♂ (SPC000171), 1♀ (SPC000170), Harlan County, Pine Mountain , Kentenia State Forest, Goss Park Campground (36.92358°N, - 83.22477°W, 777 m), 9.viii.2003, 23:30 (colls: P. Marek and D. Beamer) . 1♂ (SPC001017), 1♀ (SPC001024), Leslie County, Cawood Recreation Site , about 5.4 rd km north of junction KY-221 and US-421 (36.93645°N, - 83.37294°W, 404 m), 27.vii.2006, 19:00 (colls: P. and B. Marek) .

Figures

Figure 34. Brachoria sheari 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 = 2.10 mm).

Figure 35. Brachoria splendida (Causey, 1942). 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 = 2.00 mm).