Brachoria, , Hoffman, 1971

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 : 825-826

BRACHORIA TAXONOMY

CLASS DIPLOPODA DE BLAINVILLE IN GERVAIS, 1844 ORDER POLYDESMIDA POCOCK, 1887 FAMILY XYSTODESMIDAE COOK, 1895 SUBFAMILY XYSTODESMINAE HOFFMAN, 1978 TRIBE APHELORIINI HOFFMAN, 1980 GENUS BRACHORIA CHAMBERLIN, 1939 COMMON NAME: ‘THE APPALACHIAN MIMIC MILLIPEDES’

Brachoria Chamberlin, 1939 . Type species: B. initialis Chamberlin, 1939: 3 ; by original designation.

Synonyms: Tucoria Chamberlin, 1939 , synonymized by Keeton, 1959; Anfractogon Hoffman, 1948 , synonymized by Chamberlin & Hoffman, 1958. These taxa were established based on gonopodal morphology: Tucoria for species with bulky and enlarged gonopods ( B. calceata , Brachoria kentuckiana , Brachoria splendida , and B. viridicolens ) and Anfractogon for certain populations of B. ochra with bifurcate acropodal apices. I agree with synonymy of these genera in Brachoria – specifically Tucoria is not monophyletic, and similar ranges of acropodal modification, including bifurcation, are present within other species of Brachoria .

Species: Brachoria badbranchensis sp. nov.; B. blackmountainensis sp. nov.; B. calceata ( Causey, 1955) ; B. campcreekensis sp. nov.; B. cedra Keeton, 1959 ; B. conta Keeton, 1965 ; B. cumberlandmountainensis sp. nov.; B. dentata Keeton, 1959 ; B. divicuma Keeton, 1965 ; B. electa Causey, 1955 ; B. enodicuma Keeton, 1965 ; B. evides ( Bollman, 1887) ; B. flammipes sp. nov.; B. glendalea ( Chamberlin, 1918) ; B. gracilipes ( Chamberlin, 1947) ; B. grapevinensis sp. nov.; B. guntermountainensis sp. nov.; B. hansonia Causey, 1950 ; B. hendrixsoni sp. nov.; B. hoffmani Keeton, 1959 ; B. hubrichti Keeton, 1959 ; B. indianae ( Bollman, 1888) ; B. initialis Chamberlin, 1939 ; B. insolita Keeton, 1959 ; B. kentuckiana ( Causey, 1942) ; B. laminata Keeton, 1959 ; B. ligula Keeton, 1959 ; B. mendota Keeton, 1959 ; B. ochra ( Chamberlin, 1918) ; B. plecta Keeton, 1959 ; B. sheari sp. nov.; B. splendida ( Causey, 1942) ; B. virginia sp. nov.; B. viridicolens Hoffman, 1948 .

Tribal affiliation: Brachoria is placed with other taxa in the tribe Apheloriini based on the following characters: Male gonopodal characters: Telopodite-coxa joint articulated at 180° angle. Prefemoral process present, short and stout; or absent, never long, or acicular. See also diagnoses of Apheloriini in Shelley & Whitehead (1986: 205) and Hoffman (1980: 187).

Diagnosis: Large (4–6 cm in length), broad, ‘flatbacked’ millipedes. Bright aposematic coloration in yellow, orange, red, violet that commonly mimics other sympatric apheloriine genera. Brachoria individuals frequently mimic the yellow and black spots or alternating yellow and black bands of Apheloria ( Marek & Bond, 2009) . Members of the genus Brachoria are distinct from other apheloriine genera based on the following combination of characters. Male exoskeletal characters: collum with carinae present on anterolateral margins, absent medially; carinae rarely completely absent. Caudolateral corners of paranota usually rounded cephalically on anterior body rings (1–4), acute, projecting caudally (beyond paranotal caudal edge) throughout posterior body rings (11–19); or acute, projecting caudally on all body rings (1–19) in B. guntermountainensis , B. ochra , and B. initialis . Male gonopodal characters: distinct cingulum present ( Fig. 2 , cg). Cingulum proximal (located distance less than half length of acropodite distally from coxa), or distal (located distance greater than half length of acropodite distally from coxa). Note: other apheloriine genera lack a cingulum, except for individuals in the genus Appalachioria , see below for distinguishing characters between individuals in the genera Brachoria and Appalachioria . Prostatic groove ( Fig. 2 , ps) located marginally on acropodal base. Acropodite occasionally bulky (in ten out of 34 species); width greater than tibia on leg pair nine (species with bulky gonopods: B. splendida , Fig. 2 ; B. blackmountainensis , B. calceata , B. campcreekensis , B. cumberlandmountainensis , B. kentuckiana , B. laminata , B. plecta , B. sheari , and B. viridicolens ). Acropodite distal zone surface usually directed anterolaterally, twisted one-quarter turn clockwise; or occasionally directed posterolaterally, twisted one-quarter turn counterclockwise. Note: individuals of Brachoria may be confused with Apheloria and Appalachioria , but can be distinguished from Apheloria by the presence of the following characters (viewed with a 20¥ loupe): acropodite with midlength transverse groove, cingulum ( Fig. 2A–C , cg); acropodite, when viewed ventrally C- or D-shaped, acropodal apex not coiled, or overlapping prefemoral region, not circular. Individuals of Brachoria can be distinguished from Appalachioria by the presence of the following characters (viewed with a 20¥ loupe): collum with carinae present on anterolateral margins, absent medially; caudolateral corners of paranota usually rounded cephalically on anterior body rings (1–4) and acute, projecting caudally (beyond paranotal caudal edge) throughout posterior body rings (11–19); not rounded on all segments (1–19) as in Appalachioria .

Distribution: Predominately distributed in the Valley and Ridge and Cumberland Plateau provinces from southern West Virginia to north-eastern Kentucky, south to eastern Tennessee, and south-western Virginia ( Fig. 1 ). The range of the genus extends into the historically unglaciated south-eastern corner of Indiana, north-eastern Mississippi and Alabama, and north-western Georgia. The species B. initialis is broadly distributed in the coastal plain in Alabama, Mississippi, and Louisiana (extending west of the Mississippi River).

Ecology: Brachoria are predominately found in Appalachian mixed mesophytic deciduous forests ( B. cedra sometimes occur in cedar glades) beneath decomposing leaf material on the forest floor. Individuals are less frequently encountered in Tsuga canadensis, Rhododendron coves.

BRACHORIA BADBRANCHENSIS SP. NOV.

Figures

Figure 1. Distribution of Brachoria species in the eastern US. Specimens colour-coded by species. A, overview map of North America; inset (solid line), area of Brachoria species distribution in the south-eastern US. B, map of south-eastern US; inset (dashed line), area of highest species density in the Cumberland Mountain Thrust Block region, Cumberland Plateau, and Valley and Ridge regions. Base maps by U.S. Geological Survey, EROS Data Center and the National Atlas of the United States (http://nationalatlas.gov/).

Figure 2. Top, Brachoria species left male acropodites (with setae removed): (left) medial view and (right) magnified apical view. A–C, gonopod scanning electron micrographs, labelled with key anatomical features. A, ‘bulky’ gonopod from Brachoria splendida (SPC000171), scale bar = 1 mm; B, ‘narrow’ gonopod from Brachoria hendrixsoni (SPC000219), scale bar = 1 mm; C, acropodite from B. hendrixsoni, magnified view of cingulum and prostatic groove. D, Brachoria initialis gonopod diagram, colour-coded by region – dashed lines indicate junctions between (moving distally from the prefemur) the precingular region, postcingular region, and apex. Abbreviations: ap, acropodite; ax, acropodite apex; ca, cannula; cg, cingulum; cx, coxa; post-cg, postcingular region of acropodite; pre-cg, precingular region of acropodite; pf, prefemur; pp, prefemoral process; ps, prostatic groove. The gonopod comprises the acropodite, prefemur, and coxa.