Joelia Oudemans 1906
Creators: name: Behan-Pelletier, Valerie M.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Sarcoptiformes
Oribatellidae
Joelia

description: Joelia Oudemans 1906
Type species: Oribates fiorii Coggi 1898, p. 77.
Joelia fiorii (Coggi, 1898), Oudemans 1906, p. 61. Joelia fiorii (Coggi, 1898), Grandjean 1956b, p. 450
Diagnosis. Adult. Species comprising this genus are unique among Oribatellidae (Grandjean 1953b, 1956b, Bernini 1975) in having the following combination of character states. Rostrum with distinct, convex medial crest, rostral margin flattened to slightly undulating. Octotaxic system developed as 4 pairs of porose areas. Notogaster with 10 pairs of setae, c and la positioned laterad lm. Lenticulus absent. Lamellae long, broad, with large cusps, fused along basal half of length. Lamellar cusp with lateral dens, with or without tooth distally; with or without small medial dens. Translamella present or absent. Longitudinal thickened keel present ventrally on lamella (carène a π of Grandjean 1956b). Nerve canal of seta le extending through thickness of keel, from insertion of seta on cusp to prodorsum. Dorsophragmata separate or fused medially, very short, almost effaced on posterior of prodorsum. Lamellar seta arising ventromedially on cusp. Bothridium long, flask-shaped, with indentation laterally. Genal tooth subtriangular in shape, with or without longitudinal ridge ventrolaterally, with or without dens ventrodistally. Tutorium broad, lamelliform, rectangular to slightly tapered, slightly to strongly convex medioventrally, with dens distally or dorsodistally, tutorium extending well anterior of insertion of rostral seta. Pedotectum I and coxisternal region striate. Pedotectum I with small concave indentation in ventral wall; this indentation, weakly to very visible when viewed ventrally with transmitted light. Pedotectum II forming small to large tubercle dorsoposteriorly close to pleural wall. Custodium present. Postanal porose area present, small. Axillary saccule present at base of palp. Chelicera chelate-dentate, narrowed or not. Rutellum normal, pantelobasic. Mentum with large tectum or without tectum; with or without recurved ridge. Seta m of gena subequal in size and shape to seta a. Palp setal formula 0–2– 1–3–9(1); eupathidium acm subequal in length to solenidion, forming double horn with solenidion along length. Humerosejugal porose organs Am and Ah expressed as porose areas, distinct, on plural surface in depressions, or Ah on convex part of plural surface. Porose organ Al present or absent, if present, expressed as porose area. Epimeral setal formula 3-1-3-3 or 3-1-3-2, seta 4c present or absent. Femur III with seta l’ absent; seta v' of genua I and II present. Setae l” of genu and tibia II, and genu I spinose, thicker, more heavily barbed than other setae on these segments. Setae l” of tibia I setose. Anterodorsal spines present between solenidia φ1 and φ2 on tibia I (too small to see on figure 9A).
Immatures. Knowledge of immature Joelia is based solely on one deutonymph described by Grandjean (1956b). He collected it along with nine adults of Joelia fiorii and made the tentative association because of the length of the chelicera, which although shorter than those of J. fiorii adults, were longer than those of nymphs of known Oribatella or Ophidiotrichus. He described long prodorsal setae, setae da equal in size to dm and dp, setae da not serpentine in shape, not showing any modification for attachment of scalp of preceding instar. Setae da, dm, dp long, roughened, directed posteriorly, pairs equidistant, forming two longitudinal rows. The deutonymph did not carry scalps, but he could not determine whether it was because Joelia nymphs do not bear scalps, or because they had fallen off.
Remarks. This diagnosis is based on the description of Joelia fiorii by Grandjean (1956a, 1956b) and the new species described below. Grandjean (1956b) did not describe or illustrate the palp or legs of J. fiorii; thus the palp setal formula and data on leg setation given above are from J. applachica sp. nov., described below.
The gnathosoma of Joelia fiorii is elongated, with a large mental tectum described as being similar to that of Galumnidae (Grandjean 1932, 1956a). The type species of Oribatella, O. quadridentata Banks, also has an elongated gnathosoma, but it lacks the large mental tectum of J. fiorii (Behan-Pelletier 2011). The chelicerae of both species are elongated, but not pelopsiform.
Grandjean (1956b) described the keel on the ventral surface of the lamella, which he labelled a π. Among Oribatellidae, this keel is only known in Joelia, and is well developed in J. appalachia sp. nov.
Joelia appalachia sp. nov. (Figs. 2E, F, 6, 7, 8A, 9A–D)
Material examined: Holotype: adult female, West Virginia, Pocahontas Co., Hills Creek Falls area, 27km E Richmond, 3.viii.1986 (EEL) 3000’, from deciduous litter, rotten wood, moss and substrate, deposited in the CNC, type number 24129. Paratypes 18 females, 17 males with same data as holotype; West Virginia, Randolph Co., Stuart Park Recreation Area, 8km W. Elkins, 30.vii.1986 (EEL) 1 female, 2 males from mixed deciduous litter, primarily Rhododendron. Paratypes deposited in the CNC, FMNH, USNM, and RNC.
Diagnosis. Adult. Total length 300–335 µm. Rostrum with distinct, strongly convex medial crest (Figs. 6, 2E). Notogastral porose areas about 5 µm in diameter. Notogastral setae smooth, 28–42 µm, with c seta longest; lm posteromediad Aa and lp anteriad A1; mutual distance h1–h1 about 23 µm, p1–p1 about 18 µm. Lamella 120–131 μm long, of which cusp 104–109 μm; 48–54 μm wide at level of insertion of seta le. Lamellar cusps fused proximally for length of 45–48 µm. Lateral edge of lamella curved medioventrally; anterolateral edge of lamella curved or not ventrally (Figs. 7, 2E). Length of lamellar keel about 45 µm, distance between lamellar keels about 8 µm (Figs. 6, 2F). Lamellar cusp with large lateral dens, about 64 µm, pointed anterolaterally, medial dens absent; lamellar seta arising at anterior end of keel, about 91 µm in length. Insertion of lamellar seta expanded and flaskshaped (Fig. 2F, arrow). Seta ex very thin, about 12 µm. Genal tooth broad, subtriangular in shape, with longitudinal ridge ventrolaterally, with dens ventrodistally (Fig. 8A). Tutorium broadly subrectangular, slightly tapered, 91–103 μm long, of which cusp 49–53 μm, concave proximoventrally, distal margin with 3–4 dentes. Custodium 34–40 μm long (Figs. 7, 8A). Epimeral seta 3c similar in shape to other epimeral setae, about 27 µm; 4c thin, short, about 11 µm (Fig. 7). Chelicera not elongated. Mentum without tectum, with recurved ridge distally (Fig. 7).
Description. Adults. Dimensions: Total length: females (n = 10) 325 µm (range 320–335); males (n = 5) 310 µm (range 300–315). Notogastral width: females (n = 9) 211 µm (range 200–215); males (n = 5) 212 µm (range 205–215).
Integument: Prodorsum, notogaster, anal plates, genital plates, venter and mentum smooth to microtuberculate. Lamellae with distinct irregular striae laterally (Fig. 6); pedotectum I proximally with irregular transverse striae (Fig. 7).
Prodorsum: Rostrum with distinct medial crest (Figs. 6, 2E); rostral margin medially rounded (Figs. 6, 7). Lamella 120–131 μm long, of which cusp 64–70 μm; 48–54 μm wide at level of insertion of seta le. Lateral edge of lamella curved medioventrally; anterolateral edge of lamella curved or not ventrally (Fig. 7). Lamellar cusps fused along proximal 45–48 μm (Figs. 6, 2E). Translamella without tooth, 3–9 μm at greatest width. Medial dens on lamellar cusp absent; lateral dens without teeth, pointed anterolaterally (Figs. 6, 2E). Seta ro 77–90 µm long, strongly barbed along length, acuminate, curved anteromedially. Seta le 92–97 µm long, thick, very heavily barbed, tapered, arising from anterior of lamellar keel (Figs. 6, 2E); insertion expanded and flask-shaped (Fig. 2F). Seta in 131–155 µm long, barbed (less so than le), tapered; pair parallel, mutual distance 51–53 µm (Fig. 6). Bothridial seta 100–110 µm long, fusiform, with barbed, distally tapered head; head directed slightly anteromedially (Figs 6, 2E). Exobothridial seta about 27 µm long, thin, weakly barbed.
Lateral region of podosoma: Genal tooth subrectangular, with dens ventrodistally, with longitudinal ridge ventrolaterally; covered by edge of rostrum dorsally (Fig. 8A). Tutorium narrowly subrectangular, slightly tapered, 91–103 μm long, of which cusp 49–53 μm, concave proximoventrally, distal margin with 3–4 dentes (Fig. 8A). Custodium 34–40 μm long (Figs. 7, 8A). Porose area Al about 5 μm in diameter (not illustrated on fig. 8A).
Notogaster: Length subequal to width. Anterior margin undulating, almost straight in interlamellar region; convex region lateral of bothridium with about 8–10 transverse ridges (Fig. 6). Pteromorph striate distally, with minute dens anteroventrally. Porose areas Aa about 5 μm in diameter, A1–A3 about 4 μm. Notogastral setae very weakly barbed, 20–43 μm long, with c seta longest, lm posteromediad Aa, and lp anteriad A1; mutual distance p1– p1 about 18 μm, h1–h1 about 23 μm (Fig. 6).
Ventral Region: Epimeral setae mostly about 11–27 μm long, barbed acuminate, 3c about 27 μm long, distinctly barbed, 4c about 11 μm long, similar in shape and length to 1a, shortest epimeral setae (Fig. 7). Genital, aggenital, anal and adanal setae smooth; genital setae about 8–10 µm, others 4–6 µm. Genital setae 2+4 or 1+5. Lyrifissure iad anterolateral of anal plate, almost perpendicular. Postanal porose area about 8 x 8 μm.
Gnathosoma: Small axillary saccule present at base of palp, 4 x 2 µm. Chelicera chelate-dentate, not elongated; length about 70 μm. Mentum without tectum, with small recurved ridge distally (Fig. 7, arrow).
Legs: Setation (I to IV) (Figs. 9A–D): trochanters, 1-1-2-1; femora, 5-5-2-2; genua, 3(1)-3(1)-1(1)-2; tibiae 4(2)-4(1)-3(1)-3(1); tarsi, 20(2)-15(2)-15-12. Setae l” of genu and tibia II about 21 and 18 μm, respectively. Setae l” of genu I, and genu and tibia II spinose, thicker than other setae on these segments. Seta l’ of genu III and tibia IV spinose (Figs. 9A–D). Setae l” of genu and tibia I about 20 and 32 μm, respectively. Two very small anterodorsal spines present on tibia I between solenidia φ 1 and φ 2 (not illustrated on Fig. 9A).
Immatures. Unknown.
Etymology. This species is named as a noun in apposition from Appalachia, a cultural region in Eastern USA that is dominated by habitats of the Appalachian Mountains, and home to this species.
Remarks. This species is considered a member of Joelia because of the presence of the distinct, strongly convex medial crest on the rostrum, the longitudinal thickened keel ventrally on lamella with the nerve canal of seta le extending through the thickness of the keel, and pedotectum II having a small tubercle dorsoposteriorly close to the pleural wall. However, J. appalachia differs from the type-species, J. fiorii, in the following characters, and when immatures are discovered its placement may be challenged. The chelicera of J. appalachia is not elongated and the subcapitulum lacks the large mental tectum of J. fiorii (Grandjean 1956a). The attachment of the tutorium of J. fiorii to the prodorsum is forshortened in comparison to that of other known Oribatellidae (Grandjean 1956a, his Fig. 2A), that of J. appalachia is normal for the family. The genal tooth of J. fiorii is rounded distally (Grandjean 1956a, his Fig. 2A), whereas that of J. appalachia is pointed ventrodistally (Fig. 8A); however, this character is variable among species of Oribatella (Behan-Pelletier 2011). In J. fiorii the distance between the anterior of the coxisternum and the genital plates is longer than in other known species of Oribatellidae (Grandjean 1956b, his Figs B, C); this region is not elongated in J. appalachia.
Marshall et al. (1987) omitted Joelia americana (Haller 1884) from their treatment of North American Oribatida as they found no confirmation of its occurrence in North America, though its occurrence was reported by Michael (1898, p. 18) and Ewing (1909, p. 380). I have not found J. americana in North America. The illustration of J. americana by Haller (1884) shows the lateral dens of the lamellar cusp as having teeth, which are absent from J. appalachia. In addition, Haller’s description gives a body length of 390 µm, which is significantly larger than that of J. appalachia.
Distribution and Ecology. This species is only known from rich deciduous forest litter in the central Appalachians. Gravid females carry two eggs; gut contents include dark fungi and spores.
description: Published as part of Behan-Pelletier, Valerie M., 2013, Adoribatella, Ferolocella, Joelia and Ophidiotrichus (Acari, Oribatida, Oribatellidae) of North America, pp. 254-284 in Zootaxa 3637 (3) on pages 265-271, DOI: 10.11646/zootaxa.3637.3.2, http://zenodo.org/record/224260