Nothrolohmannia thailandica, Fuangarworn, Marut & Lekprayoon, Chariya, 2012

Fuangarworn, Marut & Lekprayoon, Chariya, 2012, Description of two new species of Nothrolohmannia Balogh, 1968 (Acari: Oribatida: Hypochthoniidae) from Thailand, with key to known species, Zootaxa 3170, pp. 45-54 : 45-49

Nothrolohmannia thailandica sp. nov.

( Figs. 1–2 )

Diagnosis. Nothrolohmannia with the following combination of character states: rostral setae with hyaline vane; sensillus pectinate without hyaline coating; two notogastral porose areas between setal pairs c1–d1 large, elongate, and undivided; notogastral setae attenuate with hyaline coating; seta c1 relatively short, not exceeding distance between c1–d1; setae e1–2 relatively short, about half length of other dorsal setae; epimeral setae uniformly simple; posterior sternal apodeme short; genital setae heteromorphic; and three pairs of adanal setae present.

Female. Dimensions. Body length of holotype 325 (range of paratypes, 325–350); body width 200 (200–210); body height 110 (90–125). Color uniformly yellow.

Prodorsum ( Fig. 1 A & C). Outline subtriangular, truncated anteriorly. Anterior portion hammerhead-like, about half maximum width of prodorsum, and bearing rostral seta (ro). Dorsolateral margin with flange partly overhanging retracted leg I, its surface devoid of spicules. Median depression present, flanked by pair of elongate swellings running from bothridium to level of lamellar seta (le), gradually narrowing and lessening in height. True rostral margin entire; submargin with row of about 20 denticles. Seta ro biramous with well developed vane; anterior ramus whip-like and curved ventrally to rostral margin; posterior ramus attenuate, about two-thirds length of anterior ramus and curved posteriorly. Seta le, interlamellar seta (in) and anterior exobothridial seta (exa) long, attenuate with unilateral hyaline and ciliate coating; exa curved upward, le posteriorly, in anteriorly; posterior exobothridial seta (exp) short, simple without hyaline coating. Bothridium typical of subfamily ( Norton 2001); sensillus (ss) 75 long, uniformly pectinate on one side with about 20 barbs, opposite side with sparse microbarbs; hyaline coating absent.

Notogaster. In dorsal view ( Fig. 1 A), anteriorly truncated with parallel sides and posteriorly rounded. In lateral view ( Fig. 1 C), dorsum slightly arched, venter almost straight. Surface with dense spicules; undulating due to presence of shallow depression and lower ridges; in extended specimens, relatively broad transverse groove present behind setal row e, surface on groove with shorter spicules ( Fig. 1 C). Trace of fused transverse scissures evident as transverse lines bordering setal row e; other traces outline paired subtriangular region around seta f2. Humeral tubercle prominent bearing seta c3. With two large, elongate, unpaired porose areas in tandem between setal pairs c1–d1; anterior area longer (63), slightly arched near ends, with nine cross lines; posterior area shorter (43), with four cross lines. Sixteen pairs of notogastral setae present, all attenuate with membranous hyaline and ciliate coating; viewed perpendicular to curvature, coating about twice setal width at base, gradually narrowing to tip; asymmetrical bilateral coating sometimes developed. Seta c2 with simple unbranched core, but with unique, anteriorly directed basal lobe in hyaline coating, giving false impression of bifurcation. Seta c1 not reaching insertion of d1; setae e1, e2 about half size of adjacent setae, and not reaching level of seta f1 insertion. Setae ps2 and ps3, on pleuraspis, shorter than dorsal setae and usually with bilateral hyaline coating. Lyrifissures ia, im, and ips present at normal positions; lyrifissures ip and ih not discerned due to dense spicules.

Coxisternum ( Fig. 1 B). Anterior margin of epimere I truncate near midline, oblique laterally. Short, triangular sclerotized boss present posteriorly to insertion of leg I. Along anterolateral margin of epimere I, apodeme I developed, not fused at midline but turning posteriorly to form short extension; apodeme II almost transverse, and extending close to midline. Anterior sternal apodeme short, located between setae of pair 2a. On fused epimeres III–IV, posterior sternal apodeme broken into two short pieces and widely spaced; shorter anterior piece near sejugal articulation, longer posterior piece between setae of pair 4b ( Fig. 1 B). Apodeme III well developed, slightly curved and reaching near posterior sternal apodeme; apodeme IV inconspicuous. Prominent, elongated tubercle present in position of discidium, between insertions of legs III and IV. Epimeral setation 3-1-3-4; all setae short and simple, without hyaline coating.

Anogenital region ( Fig. 1 B). Genital shield slightly shorter than anoadanal shield; usually with 10 genital setae of which six setae simple, located along inner margin and four setae longer with hyaline coating, located near outer margin. All three genital papillae similar. Preanal shield similar to that of congeners. Fused anoadanal shield with longitudinal groove, interrupted anteriorly in region of valve interdigitations; with two simple anal setae (an1–2), and three hyaline coated adanal setae (ad1–3), seta ad3 smallest.

Gnathosoma ( Figs. 1 B, 2A–C). Subcapitulum anarthric, posteriorly truncate, laterally oblique; with four pairs of setae; setae h, m, and a attenuate with hyaline coating, seta n basally barbed without coating. Adoral setae (or1– 3) and rutellum ( Fig. 2 A–B) characteristic of family. Palp setation (trochanter to tarsus, solenidion in bracket): 0-2- 1-3-9(1); setal homology depicted in Fig. 2 C. With short sclerotized turbercle posterior to palp insertion; supracoxal seta (ep) spine-like, born on (and almost perpendicularly to) short turbercle. Chelicera chelate-dentate, relatively slender distally; with one minute cheliceral seta.

Legs ( Fig. 2 D–H). Legs relatively short; all monodactyl, all claws with dorsal scale. Basal segments usually provided with ridges or tubercles; trochanter I–IV distally with half-collar tubercle, but less developed on trochanter III–IV; femora I – IV with basal apophysis: auriculate on femora I–II, subtriangular on femora III–IV; femur I with half-collar tubercle at level of apophysis on abaxial face. Surface of all trochanters and femora spiculate, except basal portion of femoral segments; genua, tibiae and tarsi microreticulate. Setation of legs I–IV (from trochanter to tarsus, famulus included, solenidion in brackets) as follows: leg I 0-5-3(1)-5(1)-19(2); leg II 0-5-3(1)- 5(1)-13(2); leg III 2-3 -2(1)-3(1)-11 and leg IV 2-3 -2(1)-3-12. Setal homologies illustrated in Fig. 2 D–H. Forms of leg setae generally similar to those of N. baloghi Norton , except seta bv” on femur I, with broader vane basally but abruptly narrowed in distal half. Seta d on tibiae I–II coupled with its respective solenidion; famulus setiform; solenidion φ of tibia I, extremely long, flagellate; other solenidia elongate but not tapered, ω 1 on tarsus I curving to abaxial face.

Males and immatures. Unknown.

Material examined. Female holotype (in alcohol, CUMN-AC20012.01), Wua Ta Larb Island, Ang-Thong Archipelago National Park, Surat Thani Province, Thailand (9°38'12"N, 99°40'13"E); ex. leaf litter at forest margin; 24-IV-2009; coll. M. Fuangarworn (Field No. MF 2009-16 /1). Five paratypes, (CUMN-AC2012.02–06) with same data as holotype.

Distribution. Known only from its type locality — Surat Thani Province, southern Thailand ( Fig. 6 ).

Etymology. The new species is named after the country of its type locality, Thailand.

Remarks. See Remarks of N. flagellata sp. nov., described below.

Figures

FIGURE 1. Nothrolohmannia thailandica sp. nov., female. A) Dorsal view; B) ventral view; and C) lateral view; legs and palps omitted or partially drawn.

FIGURE 2. Nothrolohmannia thailandica sp. nov., female. A) Adoral setae, or 2 - 3 removed on right side; B) rutellum, ventral view; C) palp and corner of subcapitulum, ventrolateral view; D) leg I; E) leg II; F) tarsus II; G) leg III; and H) leg IV; all legs in abaxial view.

FIGURE 6. Distributional records of Nothrolohmannia species in the Indo-Australasian region.